technetium-tc-99m-exametazime and Brain-Neoplasms

Radiotracers called chemical microsphere are widely accepted as brain perfusion agents. Following the intravenous administration, these drugs are transported via the artery to the brain, cross the intact blood-brain barrier, and enter the brain tissue. Once the tracer flows into the brain, the efflux of the tracer is prevented by some trapping mechanism, resulting in prolonged retention. Because the distribution of the accumulated tracer remains approximately consistent with regional cerebral blood flow for a relatively long period, high-quality SPECT images reflecting the distribution pattern of cerebral blood flow can be acquired. However, unlike true microsphere, cerebral kinetics of the brain perfusion agents is complicated, and various causes may produce discrepancy between the distributions of the tracer and blood flow. In this review, cerebral kinetics of the brain perfusion agents used commonly is discussed. The knowledge of the mechanism of brain accumulation appears to be essential to appropriately determine the tracer of choice and interpret the obtained images.

Topics: Amphetamines; Brain; Brain Neoplasms; Cerebral Infarction; Cerebrovascular Circulation; Cysteine; Humans; Iodine Radioisotopes; Iofetamine; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals; Technetium Tc 99m Exametazime

Recent and future evolutions in neuroSPECT apply to radiopharmaceuticals techniques and the synergistic use of different imaging modalities in the work-up of neurological disorders. The introduction of Technetium labelled perfusion tracers, which could pass the intact blood-brain barrier, together with the implementation of the tomographic principle, by making the conventional gamma camera rotating, enabled estimation of regional cerebral blood flow and indirectly of local brain metabolism. In addition at present Thallium-201 and Tc-99m sestaMIBI allow functional detection of viable tumor tissue, without interference from previous surgery or radiotherapy as seen using CT-scan or MRI. In neurology this has led to the recognition of SPECT by the American Academy of Neurology (Therapeutics and technology subcommittee) as an established or promising tool in major neurological disorders such as dementia, stroke and epilepsy, while other domains such as brain oncology are considered investigational. With regard to radiopharmaceuticals, recent evolutions mainly include the development of mostly Iodine-123 labelled receptor ligands, some of which are already commercially available. For instrumentation advances consist e.g. of multidetector systems equipped with fanbeam collimators, attenuation and scatter correction or coincidence detection. Given the present role for nuclear neurology it may be expected that these additional radiopharmaceutical and technical innovations will continue to stimulate the development of SPECT of the brain. The synergistic use of several imaging techniques such as CT, (functional) MRI, source imaging, SPECT and PET represents a multimodal holistic approach to probe cerebral functions for research and clinical purposes. Clinical indications, in which this synergistic use is illustrated include e.g. support of the clinical diagnosis of dementia of the Alzheimer type, presurgical ictal detection of seizure focus, detection of acute ischemia and differential diagnosis between radiation necrosis and brain tumor recurrence. The synergistic use of imaging modalities, optimally applied using image fusion, allows to overcome the intrinsic limitations and to enhance the specific advantages of the different approaches as it leads to increased precision and accuracy, as well for spatial anatomofunctional correlation as for quantification.

Topics: Alzheimer Disease; Brain Ischemia; Brain Neoplasms; Epilepsy; Humans; Image Processing, Computer-Assisted; Magnetic Resonance Imaging; Mental Disorders; Nervous System Diseases; Neurology; Nitriles; Technetium Tc 99m Exametazime; Tomography, Emission-Computed; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

Brain imaging has become an integral part of the evaluation of neurological and psychiatric disorders. Functional imaging techniques, SPECT and PET, together with structural modalities, CT and MRI, are widely employed. Functional imaging studies are routinely used in the diagnostic workup of patients with well-characterized neurological disorders, such as epilepsy and brain tumors, and have a growing role in research on psychiatric disorders without known mechanisms such as depression and schizophrenia. Furthermore, many well-defined neurological disorders manifest prominent psychiatric symptomatology which may pose difficulties in differential diagnosis. This review addresses the current knowledge of SPECT findings in patients who present with psychiatric phenomena, associated with disorders at the interface of neurology and psychiatry.

Topics: Alzheimer Disease; Brain; Brain Damage, Chronic; Brain Diseases; Brain Injuries; Brain Neoplasms; Dementia; Diagnosis, Differential; Epilepsy, Temporal Lobe; Humans; Huntington Disease; Neurocognitive Disorders; Organotechnetium Compounds; Oximes; Parkinson Disease; Regional Blood Flow; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Topics: Amphetamines; Animals; Brain Neoplasms; Deoxyglucose; Fluorine Radioisotopes; Fluorodeoxyglucose F18; Humans; Iodine Radioisotopes; Iofetamine; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Thallium Radioisotopes; Tomography, Emission-Computed; Tomography, Emission-Computed, Single-Photon

Topics: Adult; Aged; Astrocytoma; Brain; Brain Diseases; Brain Neoplasms; Cerebral Infarction; Electroencephalography; Female; Humans; Magnetic Resonance Spectroscopy; Male; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed; Tomography, Emission-Computed, Single-Photon

Topics: Brain Diseases; Brain Neoplasms; Child; Deoxyglucose; Epilepsy; Fluorine Radioisotopes; Fluorodeoxyglucose F18; Humans; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Technetium Tc 99m Sestamibi; Thallium Radioisotopes; Tomography, Emission-Computed; Tomography, Emission-Computed, Single-Photon

Topics: Brain; Brain Neoplasms; Cerebrovascular Circulation; Cerebrovascular Disorders; Humans; Isomerism; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tissue Distribution; Tomography, Emission-Computed, Single-Photon

Although TI-201 SPECT has been used to evaluate the malignant grade of cerebral gliomas, the gold standard continues to be histopathologic examination. The authors assessed and compared the prognostic abilities of the two studies using survival analysis.. Twenty-nine patients underwent 34 sessions of TI-201 SPECT plus surgery for primary or recurrent cerebral gliomas 12 to 78 months before this analysis. Using conventional survival analyses, such as the log-rank test, Cox regression, and the Akaike cross-tab method, the authors evaluated the prognostic significance of 10 variables: histopathologic grade, TI-201 SPECT, Tc-99m HMPAO SPECT, tumor cell viability, radionecrosis, neurologic defects, clinical improvement, surgery, chemotherapy, and external beam radiotherapy.. TI-201 SPECT was most strongly related to prognosis, followed by histopathologic grade. The other variables had little prognostic value. The Cox stepwise selection procedure indicated that TI-201 SPECT was the only independent predictor of outcome, whereas histopathologic analysis was eliminated from the prognostic model. However, the Kaplan-Meier survival curve and the Akaike method indicated that histopathologically low-grade tumors were more closely associated with longer-term survival than were TI-201 low uptake tumors.. TI-201 SPECT is not only closely correlated with the histopathologic grade of tumor but is a significantly better predictor of outcome than histopathologic grade. However, histopathologic examination may provide additional information on longer-term survival. TI-201 SPECT is a valuable procedure, especially in patients in whom a histologic diagnosis of possible glioma cannot be made.

Topics: Adolescent; Adult; Aged; Algorithms; Brain Neoplasms; Child; Female; Glioma; Humans; Male; Middle Aged; Prognosis; Radiopharmaceuticals; Survival Analysis; Technetium Tc 99m Exametazime; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon

Nicotinamide (NAM) and carbogen both have been shown to enhance the radiation effect in rodent tumour models and are currently being tested in clinical trials. These agents have demonstrated to act against hypoxia and one of their underlying mechanisms could be an increase of tumour blood perfusion.. To analyse the effect of both agents on normal brain perfusion and tumour perfusion in patients with glioblastoma.. Nineteen patients with glioblastoma were studied with 99mtechnetium-hexamethylpropyleneamine oxime single photon emission computed tomography (99mTc-HMPAO SPECT) before and after administration of carbogen and/or NAM. Another six patients were studied with the same procedure but without any flow modulator and were used as controls.. Although the variations between patients were large, no significant enhancement in mean tumour and normal brain perfusion could be demonstrated with NAM or carbogen compared to the control patients. Also no consistent changes in the mean perfusion ratio between tumour and surrounding normal brain were found, suggesting an absence of a selective perfusion effect.. No significant influence of carbogen and/or NAM on tumour perfusion and normal brain perfusion could be detected with SPECT in patients with glioblastoma.

Topics: Analysis of Variance; Brain Neoplasms; Carbon Dioxide; Cell Hypoxia; Cerebrovascular Circulation; Glioblastoma; Humans; Image Enhancement; Image Processing, Computer-Assisted; Niacinamide; Oxygen; Radiation-Sensitizing Agents; Radiopharmaceuticals; Regional Blood Flow; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Magnetic resonance imaging (MRI) and computed tomography (CT) may not be reliable in the differential diagnosis of tumour necrosis, scar and recurrent tumour. We compared 201Tl-chloride SPET with CT and MRI for the differential diagnosis of these cerebral lesions. Brain SPET was performed in 40 patients after the intravenous injection of 201Tl-chloride. All 40 patients also had a CT or MRI scan, and a histological diagnosis was available for 27 of the patients. For each patient, the ratio of counts in the lesion region of interest (ROI) to counts in the contralateral ROI was calculated and found to be between 0.58 and 9.60. The ratios for high-grade gliomas, metastases and meningiomas were high (> 2.7), especially in tumours with good vascularization. A low ratio (< 1.7) was noted in patients with low-grade astrocytoma, necrosis or ischaemic lesions. There were two exceptional cases of ischaemic lesions in the luxury perfusion stage (ratios of 3.61 and 3.87), as verified by HMPAO-SPET. We found that 201Tl-chloride SPET helps to differentiate between malignant tumours, poorly vascularized benign lesions and necrosis. Differentiation between low-grade astrocytoma and non-malignant lesions was not possible, but there was a trend towards differentiating between low-grade astrocytoma and ischaemic infarction. The timing of the investigation is important to avoid false-positive results in hyperperfused ischaemic tissue.

Topics: Adult; Aged; Brain Neoplasms; Cerebrovascular Disorders; Diagnosis, Differential; Female; Functional Laterality; Gamma Cameras; Humans; Male; Middle Aged; Technetium Tc 99m Exametazime; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon

Thallium-201 chloride single photon emission computed tomography (201Tl SPECT) has been proposed as a diagnostic tool in the assessment of patients with brain tumors. We performed SPECT scans coupled with magnetic resonance imaging (MRI) in children with brain tumors to determine the sensitivity and potential value of SPECT in neuro-oncology. Each patient was injected with 2.5-3.0 mCi of thallium chloride, followed by technetium-99m HMPAO (5-15 mCi) to assess cerebral perfusion. 201Tl uptake was imaged with triple-headed SPECT in 20/24 (83%) histologically and anatomically diverse neoplasms with MRI-measurable residual disease, including 13/16 (80%) posterior fossa tumors. 201Tl SPECT demonstrated uptake in tumors with MRI volumes ranging from 0.03 to 60 cm3. 201Tl SPECT imaging was not correlated with the following MRI features: gadolinium enhancement, necrosis, exophytic, unicentric and multicentric. 201Tl uptake was not detectable in patients with tumors of maldevelopmental origin or radionecrosis. It is suggested that 201Tl SPECT is an important imaging adjunct in the assessment of children with brain tumors.

Topics: Adolescent; Brain; Brain Neoplasms; Child; Child, Preschool; Combined Modality Therapy; Female; Follow-Up Studies; Humans; Infant; Male; Neoplasm Recurrence, Local; Neoplasms, Multiple Primary; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon

Cerebral blood flow tests have increasingly been advocated for the confirmation of brain death (BD). Four-vessel angiography has been considered the most reliable investigation in the diagnosis of BD for >30 yrs, but it is invasive. (99m)Tc-HMPAO SPECT provides noninvasive, multiplanar imaging of brain tissue perfusion. The aim of this study was to check the reliability of SPECT compared with contrast angiography.. Prospective, blind study.. Neurointensive care unit of a university hospital.. Consecutive clinically brain dead patients with flat electroencephalogram.. BD was diagnosed according to Italian law. (99m)Tc-HMPAO SPECT and four-vessel angiography were performed in the same session; the rater of each investigation ignored the results of the other. Blood pressure, Sp(O2), and P(ECO2) were monitored throughout the study: any episode of hypoxia or hypotension caused exclusion of the patient from the study.. Twenty brain dead patients were enrolled. The cause of BD was head injury in seven cases (35%), subarachnoid hemorrhage in seven (30%), spontaneous hemorrhage in one (10%), brain tumors in two (10%), stroke in two (10%), and thrombosis of the sagittal sinus in one (5%). Both angiography and SPECT confirmed BD in 19 of 20 patients: angiography showed the absence of filling of intracranial arteries, while SPECT showed a picture of "empty skull." For the remaining patient, angiography showed slight and late filling of left vertebral, basilar, and posterior cerebral arteries, while SPECT showed faint traces of uptake in the posterior fossa on the right side and on the midline. For this patient, the tests were repeated 48 hrs later, and both showed the arrest of intracranial circulation, thus confirming BD.. Our results confirm the reliability of SPECT in the diagnosis of BD; because SPECT is noninvasive, it is a good candidate for the "gold standard" of diagnosis.

Topics: Adult; Aged; Aged, 80 and over; Brain Death; Brain Neoplasms; Cerebral Angiography; Cerebral Hemorrhage; Female; Humans; Intracranial Thrombosis; Male; Middle Aged; Prospective Studies; Radiopharmaceuticals; Stroke; Subarachnoid Hemorrhage; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

In this study the authors examined how to differentiate radiation necrosis from recurrent metastatic brain tumor following stereotactic radiosurgery by using positron emission tomography (PET) with L-[methyl-11C]methionine (MET).. In 21 adult patients with suspected recurrent metastatic brain tumor or radiation injury, MET-PET scans were obtained. These patients had previously undergone stereotactic radiosurgery and subsequent contrast-enhanced magnetic resonance (MR) examinations before nuclear medicine imaging. Positron emission tomography images were obtained as a static scan of 10 minutes performed 20 minutes after injection of 370 MBq of MET. On MET-PET scans, the portion of the tumor with the highest accumulation of MET was selected as the region of interest (ROI), and the ratio of tumor tissue to normal tissue (T/N) was defined as the mean counts of radioisotope per pixel in the tumor divided by the mean counts per pixel in normal gray matter. The standardized uptake value (SUV) was calculated using the same ROI in the tumor. The accuracy of the MET-PET scan was evaluated by correlating findings with results of subsequent histological analysis (11 cases) or, in cases in which surgery or biopsy was not performed, with subsequent clinical course and MR imaging findings (10 cases). Histological examinations performed in 11 cases showed viable tumor cells with necrosis in nine and necrosis with no viable tumor cells in two. Another 10 cases were characterized as radiation necrosis because the patients exhibited stable neurological symptoms with no sign of massive enlargement of the lesion on follow-up MR images after 5 months. The mean T/N was 1.15 in the radiation necrosis group (12 cases) and 1.62 in the tumor recurrence group (nine cases). The mean SUV was 1.78 in the necrosis group and 2.5 in the recurrence group. There were statistically significant differences between the recurrence and necrosis groups in T/N and SUV. Furthermore, the borderline T/N value was 1,42 according to a 2 x 2 factorial table (high T/N or low T/N, recurrence or necrosis). From this result, the sensitivity and specificity of MET-PET scanning in detecting tumor recurrence were determined to be 77.8 and 100%, respectively.. The use of MET-PET scanning is a sensitive and accurate technique for differentiating between metastatic brain tumor recurrence and radiation necrosis following stereotactic radiosurgery. This study reveals important information for creating strategies to treat postradiation reactions.

Topics: Adult; Aged; Brain Neoplasms; Cerebral Cortex; Diagnosis, Differential; Dominance, Cerebral; Female; Humans; Magnetic Resonance Imaging; Male; Methionine; Middle Aged; Neoplasm Recurrence, Local; Radiation Injuries; Radiosurgery; Sensitivity and Specificity; Technetium Tc 99m Exametazime; Tomography, Emission-Computed; Tomography, Emission-Computed, Single-Photon

To elucidate the radiation effect on the normal brain after stereotactic radiosurgery (SRS), we evaluated the change in regional cerebral blood flow (CBF) in targeted and extra-targeted areas according to the radiation dose given.. Thirteen patients who underwent SRS for brain tumors or arteriovenous malformations were included in this study. Maximum radiation doses to the lesion ranged from 24 to 37 Gy. Mean and regional CBF were measured by 99mTc-HMPAO scintigraphy with graphic analysis, performed at before, 2 weeks and 3 months (5 patients) after SRS. Under the co-registration with the CT with superimposed isodose distribution, ROIs were set on target (37-20 Gy), peri-target (20-5 Gy) and out-of-field (5-2 Gy and less than 2 Gy) areas on the quantitative SPECT images.. Significant reductions in mean CBF (by 7%) and regional CBF in the peri-target areas (by 5-7%) and out-of-field areas (by 6-22%) were recognized at 2 weeks and 3 months after SRS. Regional CBF in the target and peri-target areas did not significantly change, presumably because there was little or no normal tissue in these areas.. These results suggest that subclinical regional CBF reduction occurs after SRS in the normal brain in out-of-field of radiation.

Topics: Adult; Aged; Brain; Brain Neoplasms; Cerebrovascular Circulation; Dose-Response Relationship, Radiation; Female; Humans; Male; Middle Aged; Radiopharmaceuticals; Radiosurgery; Reproducibility of Results; Sensitivity and Specificity; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Topics: Adult; Brain Neoplasms; Cranial Irradiation; Demyelinating Diseases; Diagnosis, Differential; Humans; Magnetic Resonance Imaging; Male; Technetium Tc 99m Exametazime; Thalamus; Tomography, Emission-Computed, Single-Photon

We report a case of successful radiosurgical treatment of lesional epilepsy of mesial temporal origin. A patient presented with a 2-year history of medically intractable complex partial seizures associated with a mesial temporal angioma. Interictal scalp EEG and MEG showed focal epileptiform activity around the lesion. 99mTc-HMPAO-SPECT and 18F-FDG-PET demonstrated depressed blood flow and glucose metabolism in the corresponding temporal lobe. The patient underwent gamma knife radiosurgery for the causative lesion with a low marginal dose of 18 Gy. After treatment, the partial attack ceased without shrinkage of the lesion or peri-lesional parenchymal radiation injury.

Topics: Adult; Brain Neoplasms; Electroencephalography; Epilepsy, Temporal Lobe; Female; Fluorodeoxyglucose F18; Hemangioma; Humans; Magnetic Resonance Imaging; Magnetoencephalography; Radiopharmaceuticals; Radiosurgery; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed; Tomography, Emission-Computed, Single-Photon; Treatment Outcome

The diagnosis of brain abscess is often difficult, as the clinical symptoms are not specific. Computed tomography (CT) and magnetic resonance imaging (MRI) are highly sensitive, but different cerebral lesions, especially neoplasms, can have the same ring-like contrast enhancement. Brain abscess is a severe illness requiring rapid diagnosis to choose the most appropriate therapy. Technetium-99m hexamethylpropylene amine oxime (HMPAO)-labelled leucocyte scintigraphy is commonly used to detect an inflammatory process. The aim of this study was to present the results obtained with leucocyte scintigraphy in 65 patients with intracranial mass lesions and clinical findings compatible to or suggestive of brain abscess. The final diagnosis, based on surgery, clinical findings and stereotatic puncture, was brain abscess in 17 patients, primary brain neoplasm in 22, brain metastasis in 16, lymphoma in 2, cysticercosis in 2, hematoma in 2 and cerebral infarction in 4. 99mTc-HMPAO leucocyte scintigraphy was positive in all abscess cases. The scan was negative in the rest of the patients examined, with the exception of one lesion, which was finally diagnosed as a tumour (1 false-positive). All patients who did not have false-negative scans were treated with steroids. The sensitivity, specificity and diagnostic accuracy of leucocyte scintigraphy was 100%, 97.8% and 98.4%, respectively. In conclusion, in our experience, leucocyte scintigraphy is a valuable aid in the differential diagnosis between abscess and neoplasm.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Brain Abscess; Brain Neoplasms; Diagnosis, Differential; Female; Humans; Leukocytes; Male; Middle Aged; Radionuclide Imaging; Radiopharmaceuticals; Sensitivity and Specificity; Technetium Tc 99m Exametazime

Cerebrovascular reactivity (CVR) to acetazolamide was investigated in 41 patients with normal pressure hydrocephalus (NPH). The aetiology was subarachnoid haemorrhage in 20 patients, trauma in nine, brain tumour in three and idiopathic in nine. Mean cerebral blood flow (CBF) of the whole brain was measured by performing first-pass radionuclide angiography using 99Tcm-hexamethylpropylene++ amine oxime. Cerebrovascular reactivity was measured as the percentage change from the baseline mean CBF value after the administration of 500 mg of acetazolamide. Cerebrovascular reactivity was significantly (P < 0.001) reduced in patients with the complete triad of NPH (1.4 +/- 3.1%), regardless of the aetiology, compared with normal controls (14.7 +/- 3.3%). Patients with the incomplete triad also showed significantly (P < 0.05) reduced CVR (9.6 +/- 5.4%). Patients with the complete triad had significantly (P < 0.001) lower CVR than those with the incomplete triad. Post-operative CVR in both groups (20 patients with the complete triad and 9 patients with the incomplete triad) increased significantly, from 1.5 +/- 3.5% to 10.0 +/- 5.5% (P < 0.001) and from 8.7 +/- 4.9% to 14.9 +/- 5.4% (P < 0.05), respectively. Cerebrovascular reactivity is impaired in patients with NPH regardless of the aetiology and improves after shunting.

Topics: Acetazolamide; Adult; Aged; Aged, 80 and over; Brain Injuries; Brain Neoplasms; Cerebrovascular Circulation; Diuretics; Female; Humans; Hydrocephalus, Normal Pressure; Male; Middle Aged; Radionuclide Imaging; Radiopharmaceuticals; Regional Blood Flow; Subarachnoid Hemorrhage; Technetium Tc 99m Exametazime

We attempted to ascertain the impact of Co-60 conventional external radiotherapy (cRT) on the perfusion of normal brain tissue in relation to the radiation doses delivered to the tumors in patients with primary brain tumors.. After surgery 18 patients (pts) were due to undergo cRT with a total dose of 5400- 6400 cGy. All the patients had a Tc-99m-HMPAO SPECT study prior to cRT (basal), 15th and 30th days of cRT as well as 1 (in 6 pts), 3 (in 9 pts), and 6 (in 3 pts) months after cRT. For quantitative evaluation, the entire set of transverse slices were divided into 4 regions as frontal, parietal, occipital and temporal regions by means of a computer software program. Semi-automated quantification was performed on a total of 1392 regions in 87 studies to determine left to right ratios. An interregional difference of at least 10% was considered abnormal.. After elimination of tumor sites, 80 normal brain regions showed decreased perfusion after cRT. The percent decrease in perfusion was (mean 22.5+/-9.9) significantly higher in areas irradiated with doses > 3000 cGy (p < 0.05).. cRT has adverse effects on the perfusion of normal brain tissue for doses > 500 cGy. Our findings justify treating patients with small and limited lesions with stereotactic radiotherapy in order to minimize the adverse effects of cRT on normal tissues.

Topics: Adolescent; Adult; Antineoplastic Combined Chemotherapy Protocols; Brain; Brain Neoplasms; Child; Cobalt Radioisotopes; Combined Modality Therapy; Female; Humans; Male; Middle Aged; Radiopharmaceuticals; Radiotherapy; Radiotherapy Dosage; Regression Analysis; Remission Induction; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

The authors report a case of multiple myeloma with increased accumulation of Tc-99m hexamethylpropylene amine oxime (HMPAO) on brain SPECT. Tc-99m HMPAO is a lipophilic compound that freely passes through the intact blood-brain barrier and cell membrane and is rapidly converted to a hydrophilic form by glutathione and then retained in the neuron for several hours. In general, Tc-99m HMPAO shows decreased accumulation in brain tumors. However, some reports of increased accumulation in brain tumors, such as meningioma, glioblastoma multiforme, high-grade astrocytoma, pituitary adenoma, and multiple myeloma, have been published. The Tc-99m HMPAO uptake in these tumors has been attributed to tumor blood flow or glutathione contents within the tumor. With regard to uptake to Tc-99m HMPAO in multiple myeloma, the tumor size is considered to be an additional factor.

Topics: Blood-Brain Barrier; Brain Neoplasms; Female; Humans; Middle Aged; Multiple Myeloma; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Malignant cutaneous melanoma (MCM) is a very aggressive disease that becomes in a true problem of health because of the increase in the last 5 years. In the present paper, authors report the detection of the tumor, metastases and recurrences mean 99mTc HMPAO. We presented 5 cases of MCM patients and observed the radiopharmaceutical uptake in skin, nodules and recurrent tumor lesions. Because of the number of patients was limited, authors recommended the research with a lot of patients. The gammagraphic studies could be very important for the staging of the disease and early detection of metastases and recurrent lesions.

Topics: Bone Neoplasms; Brain Neoplasms; Evaluation Studies as Topic; Female; Humans; Lymphatic Metastasis; Male; Melanoma; Middle Aged; Neoplasm Metastasis; Neoplasm Recurrence, Local; Pelvic Bones; Radionuclide Imaging; Skin Neoplasms; Technetium Tc 99m Exametazime; Technetium Tc 99m Pyrophosphate

The effects of peritumoural oedema on cerebral blood flow (CBF) and cerebrovascular reactivity (CVR) were studied in 18 patients with alert consciousness. Hemispheric mean CBF was measured by performing first-pass radionuclide angiography using technetium-99m hexamethylpropylene amine oxime. CVR was measured as the percentage change from the baseline mean CBF value after acetazolamide administration. Patients were classified into three groups according to the severity of peritumoural oedema. The mean CBF of both hemispheres in each group was not significantly different from that of age-matched controls. CVR was preserved in patients with mild peritumoural oedema (n=6), but was significantly (P<0.01) reduced in patients with moderate (n=7) and severe peritumoural oedema (n=5). No significant correlation was found between the degree of midline shift and the mean CVR of both hemispheres (P=0.09). Surgical removal of the tumour significantly (P<0.05) improved the impaired CVR, although the mean CBF did not change. Administration of glucocorticoid improved the impaired CVR, without a change in the mean CBF, in a patient with a metastatic brain tumour. We conclude that CVR is impaired by the development of peritumoural oedema prior to changes in mean CBF.

Topics: Acetazolamide; Brain; Brain Edema; Brain Neoplasms; Cerebrovascular Circulation; Consciousness; Diuretics; Female; Humans; Male; Middle Aged; Radionuclide Imaging; Radiopharmaceuticals; Technetium Tc 99m Exametazime

The study was conducted to determine the association between dual-isotope single-photon emission computerized tomography (SPECT) scanning and histopathological findings of tumor recurrence and survival in patients treated with high-dose radiotherapy for glioblastoma multiforme.. Studies in which SPECT with 201Tl and 99mTc-hexamethypropyleneamine oxime (HMPAO) were used were performed 1 day before reoperation in 47 patients with glioblastoma multiforme who had previously been treated by surgery and high-dose radiotherapy. Maximum uptake of 201Tl in the lesion was expressed as a ratio to that in the contralateral scalp, and uptake of 99mTc-HMPAO was expressed as a ratio to that in the cerebellar cortex. Patients were stratified into groups based on the maximum radioisotope uptake values in their tumor beds. The significance of differences in patient gender, histological characteristics of tissue at reoperation, and SPECT uptake group with respect to 1-year survival was elucidated by using the chi-square statistic. Comparisons of patient ages and time to tumor recurrence as functions of 1-year survival were made using the t-test. Survival data at 1 year were presented according to the Kaplan-Meier method, and the significance of potential differences was evaluated using the log-rank method. The effects of different variables (tumor type, time to recurrence, and SPECT grouping) on long-term survival were evaluated using Cox proportional models that controlled for age and gender. All patients in Group I (201Tl ratio < 2 and 99mTc-HMPAO ratio < 0.5) showed radiation changes in their biopsy specimens: they had an 83.3% 1-year survival rate. Group II patients (201Tl ratio < 2 and 99mTc-HMPAO ratio of > or = 0.5 or 201Tl ratio between 2 and 3.5 regardless of 99mTc-HMPAO ratio) had predominantly infiltrating tumor (66.6%); they had a 29.2% 1-year survival rate. Almost all of the patients in Group III (201Tl ratio > 3.5 and 99mTc-HMPAO ratio > or = 0.5) had solid tumor (88.2%) and they had a 6.7% 1-year survival rate. Histological data were associated with 1-year survival (p < 0.01): however, SPECT grouping was more closely associated with 1-year survival (p < 0.001) and was the only variable significantly associated with long-term survival (p < 0.005).. Dual-isotope SPECT data correlate with histopathological findings made at reoperation and with survival in patients with malignant gliomas after surgical and high-dose radiation therapy.

Topics: Adolescent; Adult; Age Factors; Aged; Brain Neoplasms; Cerebellum; Chi-Square Distribution; Female; Glioblastoma; Humans; Linear Models; Male; Middle Aged; Neoplasm Invasiveness; Neoplasm Recurrence, Local; Proportional Hazards Models; Radiopharmaceuticals; Radiotherapy Dosage; Reoperation; Scalp; Sex Factors; Survival Rate; Technetium Tc 99m Exametazime; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon

Although Tc-99m HMPAO uptakes in various brain tumors have been reported, SPECT images of neurocytoma have not been described. The authors report a patient with intraventricular neurocytoma (IN) who demonstrated significant uptake of Tc-99m HMPAO and Tl-201 Cl before brain biopsy. Residual tumor after biopsy showed significant uptake of I-123 IMP on early SPECT images, but this uptake was decreased on delayed images. The three radionuclides seem to have different uptake mechanisms.

Topics: Adult; Brain Neoplasms; Cerebral Ventricles; Female; Humans; Neurocytoma; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Thallium Radioisotopes; Tissue Distribution; Tomography, Emission-Computed, Single-Photon

The relationship between impairment of consciousness and quantitative cerebral blood flow (CBF) was investigated. The mean CBF of the whole brain was measured by the Patlak-plot method using technetium-99m hexamethylpropylene amine oxime single-photon emission tomography (99mTc-HMPAO SPET) in patients with the following diseases: cerebral infarction, intraparenchymal haemorrhage, subarachnoid haemorrhage, brain tumour and cerebral contusion. The clinical symptoms were evaluated according to the severity of impaired consciousness, aphasia and dementia. Four hundred and eighty-five CBF measurements were performed. Patients with alert consciousness showed an age-related decline in mean CBF. Patients with aphasia showed a significant reduction in mean CBF compared with those without aphasia. Impaired consciousness was proportional to reduction in mean CBF regardless of types of pathology, and the size of lesion did not influence the mean CBF. Patients with dementia showed a significant reduction in mean CBF proportional to the severity of dementia. The quantitative measurement of CBF using 99mTc-HMPAO SPET is reliable in clinical evaluations.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Brain Concussion; Brain Neoplasms; Cerebrovascular Circulation; Cerebrovascular Disorders; Child; Consciousness Disorders; Humans; Middle Aged; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Discrepancies have been reported between the findings of Tc-99m HMPAO and Tc-99m ECD brain perfusion SPECT imaging. This study investigated the discrepancies in the accumulation of these tracers using dynamic SPECT to detect the super early phase of distribution. Thirteen patients with luxury perfusion or high flow states were studied with both dynamic and standard SPECT using Tc-99m HMPAO and Tc-99m ECD within 1-3 days. Standard SPECT showed discrepancies in 6 of 13 patients. Patients with meningioma and cerebral thrombosis had increased accumulation of Tc-99m HMPAO and decreased uptake of Tc-99m ECD. Patients with arteriovenous malformation, subarachnoid hemorrhage, and cavernous angioma had decreased accumulation of both tracers, but to different degrees. Dynamic SPECT showed increased or normal accumulation (i.e., essentially no discrepancy) in the first few minutes. However, Tc-99m HMPAO had a longer retention time than Tc-99m ECD in the ensuing 5-10 minutes. Dynamic SPECT revealed a similar accumulation pattern but different washout rates for the two tracers. Tc-99m HMPAO might be a more suitable tracer to detect high flow states or luxury perfusion because the findings on standard SPECT were more in agreement with those of dynamic SPECT using this tracer.

Topics: Adult; Aged; Brain; Brain Diseases; Brain Neoplasms; Cerebrovascular Circulation; Cerebrovascular Disorders; Cysteine; Female; Humans; Hyperemia; Male; Middle Aged; Organotechnetium Compounds; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

99mTc complex of hexamethylpropylene amine oxime (99mTc-HMPAO), which has been used as a tracer for regional cerebral blood flow (rCBF), has been shown to localize in primary brain tumors with wide spectrum of its uptake. The causes of the wide spectrum of tumor uptake, however, has not been understood in detail. We performed autoradiographic study with this agent to get further knowledge about HMPAO distribution in 10 cases of transplanted rat gliomas. Eight cases of rat gliomas without tumor necrosis, showed decreased uptake of 99mTc-HMPAO in the autoradiography (average tumor/normal (T/N) uptake ratio: 0.75, range: 0.40-0.90). On the other hand, two cases with tumor necrosis revealed increased uptakes of this agent in central necrotic area. T/N uptake ratios of these two cases were 1.23 and 1.42, respectively. In addition, three patients with histologically proven glioblastoma with tumor necrosis were studied after administration of 20mCi 99mTc-HMPAO. Two out of three patients showed higher uptake of 99mTc-HMPAO in tumor necrotic area than the contralateral area. Our findings suggest that the necrotic area of brain tumor may retain 99mTc-HMPAO and causes an increased uptake.

Topics: Animals; Brain Neoplasms; Female; Glioblastoma; Gliosarcoma; Neoplasm Transplantation; Rats; Rats, Inbred F344; Technetium Tc 99m Exametazime; Tumor Cells, Cultured

To determine whether the absolute value for the stump pressure might be a useful index of symmetrical cerebral blood flow (CBF), and to examine correlations with the stump pressure ratio (initial mean stump pressure/preocclusion mean arterial pressure), fifty candidates for ICA injury or permanent occlusion were evaluated preoperatively. Each was continuously monitored for mean stump pressure and arterial pressure before, during (for a total of 20 min), and after balloon test occlusion. During the occlusion, CBF was measured by 99 m Tc-hexamethyl-propyleneamine oxime (99 m Tc-HMPAO) single photon emission computed tomography (SPECT). The stump pressure and the stump pressure ratio were then compared with the results of 99 m Tc-HMPAO SPECT. Patients who failed to tolerate even brief periods of carotid occlusion and showed asymmetric decreases in CBF on SPECT were divided into high and moderate risk groups. Those with no significant changes in CBF on the occluded site formed the minimum risk group. Mean stump pressure was over 50 mmHg in 10 of a total of 25 patients in the high and moderate risk groups, and below 50 mmHg in 5 of the 25 patients in the minimum risk group. The stump pressure ratio did not exceed 56% in any but two patients in the high and moderate risk groups, and values were at least 60% in all patients of the minimum risk group. Decrease of CBF in two moderate risk group cases was localized in the posterior circulation. Difference in symmetrical CBF between the stump pressure ratio vs. the absolute value of mean stump pressure were statistically significant (p < 0.01, Fisher's Exact Test). Maintenance of a stump pressure ratio of 60% or more during test occlusion may be a more useful index for a good collateral circulation than any absolute value for mean stump pressure.

Topics: Blood Pressure; Brain Neoplasms; Carotid Artery, Internal; Carotid Stenosis; Catheterization; Cerebrovascular Circulation; Electroencephalography; Granuloma; Humans; Intracranial Aneurysm; Meningioma; Paraganglioma; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Treatment Outcome; Vascular Surgical Procedures

We report obtaining an ictal single photon emission computed tomographic (SPECT) scan in a right-handed 51-year-old man who had an astrocytoma in the left cerebral hemisphere and simple partial seizures characterized by aphasia. An epileptic seizure producing loss of speech and right-sided facial twitching occurred by chance during a SPECT scan. During the attack, he was unable to speak, but auditory comprehension and writing were intact. Ictal SPECT showed an area of increased perfusion in the left frontal cortex, with the area of highest perfusion involving the left frontal operculum to the inferior part of the left precentral gyrus. Interictal SPECT showed hypoperfusion in the same area. These SPECT findings suggest that the frontal operculum of the dominant hemisphere is one of the regions that can give rise to epileptic aphasia.

Topics: Astrocytoma; Brain Neoplasms; Cerebrovascular Circulation; Electroencephalography; Epilepsies, Partial; Frontal Lobe; Functional Laterality; Humans; Landau-Kleffner Syndrome; Male; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

Among several brain radiopharmaceuticals for SPECT imaging, 99mTc complexes of HMPAO and ECD are the most widely used. They are considered to be equal in their capacity to reflect regional cerebral blood flow; but discrepancies between HMPAO and ECD brain uptake have been reported in stroke patients. This paper reports our observations regarding discrepancies between HMPAO and ECD SPECT in 14 of 23 patients with suspected brain tumors or presumed metabolic cerebral abnormalities. We obtained similar conflicting results, namely focal HMPAO hyperactivities and isoactive ECD SPECT. The majority of these discrepancies were found in patients with brain tumors (10 of 13 patients), while only 4 of the 10 remaining patients with nontumoral process showed similar discrepant results. The physiopathology behind these observations is discussed here, and it is likely to be related to the specific response to cellular metabolic disorders rather than to perfusion disturbances.

Topics: Adult; Aged; Aged, 80 and over; Brain Neoplasms; Coronary Circulation; Cysteine; Deoxyglucose; Female; Fluorine Radioisotopes; Fluorodeoxyglucose F18; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon

To evaluate the EEG changes during seizures in children with drug resistant focal epilepsy who demonstrate hypoperfusion at the "seizure focus" interictally, but no perfusion change during the seizure.. Ictal EEG findings of six children with focal epilepsy who demonstrated hypoperfusion on rCBF SPECT after an interictal injection of (99)Tc(m) HMPAO concordant with the seizure focus, but who did not demonstrate rCBF change after an ictal injection (group 1) were reviewed. These were contrasted with the EEG data of six children matched as closely as possible for age, type of epilepsy, and pathology who did show hyperperfusion at the seizure focus on ictal scan when compared with the interictal study (group 2).. The children in group 1 showed slowing of the EEG at the time of the (99)Tc(m) HMPAO injection relative to that seen at the onset of the seizure. Those in group 2 showed rhythmic activity, or sharp waves, or both on EEG at the time of injection. This last change was also seen consistently when the EEG data of a further 13 children who also showed ictal hyperperfusion at the seizure focus were reviewed.. Ictal rCBF does not invariably increase at the seizure focus in patients with drug resistant focal epilepsy.

Topics: Adolescent; Adult; Brain Diseases; Brain Neoplasms; Cerebral Infarction; Child; Cysts; Drug Resistance; Electroencephalography; Epilepsies, Partial; Hippocampus; Humans; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Topics: Brain; Brain Neoplasms; Humans; Neoplasm Recurrence, Local; Organotechnetium Compounds; Oximes; Radionuclide Imaging; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Technetium Tc 99m Sestamibi

Topics: Aged; Brain Neoplasms; Carcinoma, Renal Cell; Humans; Kidney Neoplasms; Male; Nasal Cavity; Nose Neoplasms; Organotechnetium Compounds; Oximes; Parietal Bone; Radionuclide Imaging; Radiopharmaceuticals; Technetium Tc 99m Exametazime

In herpes simplex encephalitis (HSE), the authors noted an evident dissociation between the 99mTc-ethyl cysteinate dimer (ECD) and 99mTc-d,l-hexamethyl-propylene-amine oxime (HMPAO) single photon emission computed tomographies (SPECTs). The patient was a 5-year-old boy with diffuse type of pontine glioma, which was treated with hyperfractionated radiotherapy. Two weeks after the completion of radiation therapy, a lesion suggesting that of HSE was noted in the right fronto-temporal region on magnetic resonance images. 99mTc-HMPAO SPECT showed an increased accumulation of the tracer in this lesion. On the 99mTc-ECD dynamic SPECT, an exaggerated accumulation of the tracer was noted within 80 s of administration, followed by a rapid drop in the accumulation, resulting in a low accumulation in 10 min. It was assumed that this dissociation was due to the different mechanisms to trap HMPAO and ECD in the brain tissue.

Topics: Brain; Brain Neoplasms; Child, Preschool; Cranial Irradiation; Cysteine; Encephalitis, Viral; Glioma; Herpes Simplex; Humans; Magnetic Resonance Imaging; Male; Metabolic Clearance Rate; Organotechnetium Compounds; Oximes; Pons; Technetium Compounds; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

High-flow interstitial infusion into the brain, which uses bulk fluid flow to achieve a relatively homogeneous drug distribution in the extracellular space of the brain, has the potential to perfuse large volumes of brain. The authors report reproducible long-term delivery of 111In-diethylenetriamine pentaacetic acid-apotransferrin (111In-DTPA-Tf) (molecular mass 81 kD) to Macaca mulatta brain and monitoring with single-photon emission computerized tomography (SPECT). The 111In-DTPA-Tf was infused at 1.9 microl/minute over 87 hours into the frontal portion of the centrum semiovale using a telemetry-controlled, fully implanted pump. On Days 1, 3, 4, 8, 11, and 15 after beginning the infusion, planar and SPECT scans of 111In-DTPA-Tf were obtained. Spread of protein in the brain ranged from 2 to 3 cm and infusion volumes ranged from 3.9 to 6.7 cm3. Perfusion of over one-third of the white matter of the infused hemisphere was achieved. From brain SPECT images of (99m)Tc-hexamethylpropyleneamine oxime, which was administered intravenously before each 111In scan, the authors also found that blood perfusion in the infused region was reduced by less than 5% relative to corresponding noninfused regions. Histological examination at 30 days revealed only mild gliosis limited to the area immediately surrounding the needle tract. These findings indicate that long-term interstitial brain infusion is effective for the delivery of drugs on a multicentimeter scale in the primate brain. The results also indicate that it should be possible to perfuse targeted regions of the brain for extended intervals to investigate the potential utility of neurotrophic factors, antitumor agents, and other materials for the treatment of central nervous system disorders.

Topics: Animals; Antineoplastic Agents; Apoproteins; Autoradiography; Brain; Brain Diseases; Brain Neoplasms; Cerebral Cortex; Cerebrovascular Circulation; Extracellular Space; Gliosis; Indium Radioisotopes; Infusion Pumps, Implantable; Injections, Intravenous; Iron Chelating Agents; Macaca mulatta; Metabolic Clearance Rate; Needles; Neurons; Organotechnetium Compounds; Oximes; Pentetic Acid; Radiopharmaceuticals; Rheology; Technetium Tc 99m Exametazime; Telemetry; Tomography, Emission-Computed, Single-Photon; Transferrin

The main objective of this study was to assess whether 99mTc-HMPAO brain SPECT imaging can identify patients at high risk of developing an infarct following permanent carotid occlusion in the course of brain surgery.. Test balloon occlusion of the internal carotid artery was performed in 44 patients with a variety of head and neck tumors or aneurysms. Technetium-99m-HMPAO was injected intravenously while the balloon was initiated and a SPECT study was obtained 30 min later. Follow-up CT scans were obtained routinely for all patients at 2 wk and 1 mo following surgery, or earlier when necessary. Thirty patients and five normal volunteers had semiquantitative analysis of cerebral perfusion.. Twenty-six patients demonstrated ipsilateral perfusion abnormalities during trial occlusion. Eight patients in this group underwent bypass grafting prior to sacrifice of the artery: two resulting in infarcts. Eighteen patients had symmetric cerebral perfusion during occlusion and four of these patients underwent permanent therapeutic carotid occlusion; three patients had subsequent infarcts and the fourth patient had an impending stroke.. Patients with symmetric cerebral perfusion measured by 99mTc-HMPAO SPECT may still have a high long-term complication rate following carotid sacrifice. The scan findings in these patients were not predictive of the outcome. Patients with asymmetric cerebral perfusion had alternative therapeutic approach to carotid sacrifice and most of them had good surgical outcomes.

Topics: Brain; Brain Neoplasms; Carotid Artery, Internal; Catheterization; Cerebral Infarction; Cerebrovascular Circulation; Female; Follow-Up Studies; Head and Neck Neoplasms; Humans; Intracranial Aneurysm; Male; Middle Aged; Organotechnetium Compounds; Oximes; Postoperative Complications; Predictive Value of Tests; Risk Factors; Technetium Tc 99m Exametazime; Time Factors; Tomography, Emission-Computed, Single-Photon

To assess the use of 201Thallium SPECT and of Thallium (Tl) uptake indices in the detection and follow-up of cerebral tumors.. Two-hundred eighty 201Tl, 135 99mTc-HMPAO scintigraphies and 280 MRI studies were acquired in 135 patients with cerebral tumors. Three types of Tl uptake indices were calculated by establishing the ratio of the lesion activity to an homologous ROI (I1), the contralateral hemisphere (I2), and the contralateral scalp (I3). Intermodal coregistration between Tl-SPECT and MRI when used, was performed using Pietrzyk visual interactive method.. Tl uptake indices showed mean values of 2.0 +/- 0.5 (I1); 1.77 +/- 0.57 (I2) and 1.11 +/- 0.40 (I3) in positive scans, and of 1.05 +/- 0.22 (I1), 0.88 +/- 0.22 (I2) and 0.50 +/- 0.15 (I3) in negative scans, respectively. A linear combination of the two less correlated indices lead to a more powerful discrimination between positive and negative studies. Longitudinal follow-up studies in the same patients showed good concordance between the index values and the course of the disease.. The use of Tl uptake indices improves the accuracy of Tl-SPECT in the follow-up of brain tumors.

Topics: Adolescent; Adult; Aged; Brain Neoplasms; Child; Child, Preschool; Dominance, Cerebral; Female; Follow-Up Studies; Humans; Image Enhancement; Image Processing, Computer-Assisted; Magnetic Resonance Imaging; Male; Middle Aged; Neoplasm Recurrence, Local; Organotechnetium Compounds; Oximes; Reoperation; Technetium Tc 99m Exametazime; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon

A total of 17 patients with histologically proven diagnoses of low-grade astrocytoma (n = 4), high-grade astrocytoma (n = 8), lymphoma (n = 3), and meningioma (n = 2) were examined by using EPISTAR MR imaging. Meningiomas had the highest EPISTAR tumor/white matter contrast and low-grade astrocytomas and lymphomas the lowest. High-grade astrocytomas demonstrated elevated EPISTAR signal with marked regional heterogeneity. There was agreement between tumor vascularity by SPECT and EPISTAR in the five cases where both were done. Our results show that tumor vascularity can be assessed qualitatively by using EPISTAR without the need for contrast medium injection.

Topics: Adult; Aged; Astrocytoma; Brain Neoplasms; Cerebrovascular Circulation; Contrast Media; Echo-Planar Imaging; Female; Glioblastoma; Humans; Image Enhancement; Lymphoma; Magnetic Resonance Imaging; Male; Meningeal Neoplasms; Meningioma; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Topics: Aged; Astrocytoma; Brain; Brain Neoplasms; Humans; Male; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

We report a case of high uptake of 11C-methionine (MET), 18F-FDG (FDG) and 201Tl-Cl (Tl) in brain radiation necrosis. Twenty-one years previously, the patient had undergone surgery and radiation therapy consisting of 60-Gy for ependymoma in the anterior horn of the right lateral ventricle. The clinical features consisting of frequent seizures of the left face and arm suddenly appeared 2 wk before admission. MRI depicted a Tl and T2-prolonged lesion in the right frontal lobe. Abnormally high uptake in this area demonstrated by MET-PET, FDG-PET, Tl-SPECT or HMPAO-SPECT suggested the presence of a recurrent tumor. A craniotomy was then performed and an intraoperative electrocorticogram showed continuous epileptic spikes in the lesion. The epileptic foci were resected and the histological features of the lesion were consistent with radiation necrosis. After surgery, the seizures disappeared and the postoperative examinations with MET-PET, FDG-PET, Tl-SPECT and HM-PAO-SPECT no longer showed abnormally high uptake. Hypermetabolism and hyperperfusion related to epileptic fits are therefore thought to result in high uptake of MET, FDG and Tl in radiation necrosis.

Topics: Adult; Brain; Brain Neoplasms; Deoxyglucose; Ependymoma; Epilepsy, Frontal Lobe; Female; Fluorine Radioisotopes; Fluorodeoxyglucose F18; Humans; Methionine; Necrosis; Organotechnetium Compounds; Oximes; Radiation Injuries; Technetium Tc 99m Exametazime; Thallium Radioisotopes; Time Factors; Tomography, Emission-Computed; Tomography, Emission-Computed, Single-Photon

A 66-year-old male experienced the sudden onset of amnesia and generalized convulsions, and during the subsequent month developed consciousness disturbance, disorientation, memory disturbance, abnormal speech and behavior, pseudobulbar palsy, unsteadiness and urinary/fecal incontinence. The initial brain CT scan was unremarkable, and the MRI findings were also unremarkable, except for evidence of several scattered lacunar strokes in the cerebral white matter. 99mTc-HM-PAO-SPECT, however, revealed multifocal large hypoperfused lesions in the cerebrum. The erythrocyte sedimentation rate and serum CRP, LDH and gamma-globulin levels were elevated. CSF studies showed mild pleocytosis and increased protein levels. The patient's subsequent course was marked by fever, SIADH, adrenal enlargement, splenomegaly, pulmonary infiltration and pancytopenia. The neurological signs progressively worsened, until the patient lapsed into an apallic state and died 3 months after the onset of symptoms. Autopsy disclosed diffuse intravascular B lymphomatous proliferation in the brain, lungs, kidneys, adrenals, spleen and pancreas. Until now, the brain SPECT findings of IL were not very well known, but in our patient, SPECT was capable of demonstrating the pathophysiologic changes very precisely. SPECT was able to provide valuable information on the pathophysiology of IL and may therefore become another powerful tool in the diagnosis of IL.

Topics: Aged; Brain Neoplasms; Cerebrovascular Circulation; Humans; Lymphoma, B-Cell; Magnetic Resonance Imaging; Male; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Topics: Brain Neoplasms; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Seizures; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

A 56-yr-old woman was evaluated for removal of a tumor at the base of the skull. A test to determine the risk of carotid artery sacrifice was performed prior to surgery using carotid balloon occlusion of the left internal carotid artery and 99mTc-HMPAO perfusion scintigraphy during the occlusion. An unusual intense focus of increased uptake was seen at the site of the primary tumor in the left cavernous sinus. The tumor, found to be plasmacytoma at surgery, demonstrated only mild washout from 30 min to 2 hr after administration of 99mTc-HMPAO, with a tumor-to-cerebellum ratio of 1.6 and 1.5, respectively, and a tumor-to-contralateral cranial ratio of 2.5 and 2.4, respectively. Intracranial plasmacytoma shows good response to radiation therapy, and the differentiation of this tumor from other neoplasms is pertinent to the mode of treatment and surgical approach. Technetium-99m-HMPAO SPECT imaging may be a useful tool in distinguishing these tumors from other neoplasms at the base of the skull.

Topics: Brain Neoplasms; Carotid Artery, Internal; Constriction; Female; Humans; Middle Aged; Multiple Myeloma; Organotechnetium Compounds; Oximes; Petrous Bone; Radiography; Skull Neoplasms; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Most brain tumors show decreased uptake of blood flow tracers in brain SPECT imaging and in some cases meningiomas show increased uptake, mainly associated with high regional blood flow values. A reason for regionally increased tracer uptake is partial epilepsy when a tracer is injected during the ictal phase. We present a case of a histologically proven Grade II astrocytoma in the mesial part of the left temporal lobe that caused complex partial seizures. After tracer injection during a phase without signs of clinical seizure, markedly increased uptake of 99mTc-hexamethylpropyleneamine oxime (99mTc-HMPAO) occurred, although the tumor was partially calcified.

Topics: Adult; Astrocytoma; Brain Neoplasms; Epilepsy, Complex Partial; Humans; Male; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed, Single-Photon

Scintigraphy with 111In (indium-111)-oxine or 99mTechnetium-hexamethylpropyleneamine oxime (99mTc-HMPAO) labeled leukocytes has been used to differentiate brain abscess from brain tumor. However, there are false positive or false negative results from planar scintigraphic images. So a more specific and sensitive scintigraphic technique needs to be developed.. Planar and single photon emission computed tomography (SPECT) images were obtained and reviewed in 14 patients with intracerebral ring-enhancing lesions on computed tomography (CT) or magnetic resonance imaging (MRI). In all patients, diagnosis was confirmed by histopathologic examination. The effect of steroids or antibiotics on scintigraphic finding was examined.. Abscess was confirmed in six patients, tumor in six, tuberculoma and cysticercosis in one each, respectively. In all the patients with abscess, SPECT showed increased focal activity irrespective of steroid or antibiotic therapy. Increased radioactivity, which could not be detected on planar images, could be identified in two patients with abscess. In three of the six patients with tumor, radiolabeled leukocytes did not accumulate in the tumor. In the other three patients with tumor, SPECT showed focally increased activity that was less intense than the activity shown in the patients with abscess.. 99mTc-HMPAO labeled leukocyte SPECT is useful for the differential diagnosis of intracerebral ring-enhancing lesions, and the use of steroids or antibiotics does not influence the sensitivity of SPECT. Diagnostic sensitivity of scintigraphy with labeled leukocytes could be improved by SPECT in addition to planar image.

Topics: Adult; Aged; Brain Abscess; Brain Diseases; Brain Neoplasms; Cysticercosis; Female; Humans; Indium Radioisotopes; Leukocytes; Male; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tuberculoma, Intracranial

Nineteen patients with histologically diagnosed supratentorial cerebral neoplasms carried out CT and/or MRI, 201T1 SPECT and 99mTc-HM-PAO studies preoperatively. 99mTc-HM-PAO SPECT images revealed information about both tumoral perfusion and intracellular concentration of mediators converting 99mTc-HM-PAO to hydrophilic derivates (glutathione and other yet unknown factors) within viable tumoral cells while 201T1 SPECT images about permeability, extension of tumoral capillary network and viable tumoral cells presence. Basing on the different mechanisms of the tracer uptake, cerebral supratentorial tumors could be distinguished in three groups: 1) cerebral tumors presenting 201T1 very high uptake (201T1 index > 1.5) and homogeneous and high retention of 99mTc-HM-PAO (CBI > or = 1.05) (meningiomas, PRL adenoma); histologically these neoplasms presented very rich neoformed capillary network; 2) cerebral neoplasms with 201T1 high uptake (201T1 index > 1.5) and with inhomogeneous retention of 99Tc-HM-PAO (high grade gliomas amd metastasis); microscopically these tumors presented vascular proliferation, necrosis and high cellularity; 3) cerebral neoplasms characterized by 201T1 low uptake (201T1 index < 1.5) and lower retention of 99Tc-HM-PAO than cerebellum (low grade gliomas); at microscopic examination these neoplasms were characterized by absence of vascular proliferation and necrosis. These results suggest coupled 201T1/99Tc-HM-PAO SPECT is necessary to discriminate intra-axial from extra-axial tumor localization (lacking CT or MRI) and to detect the grade of malignancy of gliomas and tumor cell presence within necrotic areas.

Topics: Adult; Aged; Brain Neoplasms; Cerebral Hemorrhage; Female; Glioblastoma; Hematoma; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

The aim of this retrospective study was to assess the contribution of thallium-201 single-photon emission tomography (SPET) in the detection and differential diagnosis of brain tumours. In 90 patients 201Tl SPET was performed because of clinical or radiological suspicion of tumoral invasion, completed by technetium-99m hexamethylpropylene amine oxime and 99mTc-sestamibi SPET in some patients. For all tumours, diagnosis was based on biopsy or autopsy. Other diagnoses were made only after clinical and radiological follow-up for at least 6 months. Histologically tumours consisted of astrocytoma stage I or II (number of patients, n = 6), astrocytoma stage III (n = 8), glioblastoma multiforme (n = 14) and oligodendroglioma (n = 3), brain metastasis (n = 14), lymphoma (n = 3), meningioma (n = 3), pituitary adenoma (n = 2), pineal tumour (n = 1), colloid cyst (n = 1) and craniopharyngioma (n = 1). False-negative studies included pineal tumour (n = 1), colloid cyst (n = 1), craniopharyngioma (n = 1), astrocytomas stage I or II (n = 6) and stage III (n = 3), oligodendroglioma (n = 2) and metastasis in the brain stem (n = 1). Additional metastases approximately < 1.5 cm were not detected in two patients and 201Tl SPET underestimated tumoral extent in one patient suffering from glioblastoma multiforme (n = 1). A false-positive study was obtained in a patient with skull metastasis (n = 1). All 15 patients who were finally shown to suffer from ischaemic infarction had a normal SPET study 9-28 days after the onset of symptomatology. Of five patients with haemorrhagic infarction, studied within 2 weeks, four were false-positive. Of six patients with intracranial haemorrhage, studied 9-39 days later, one showed focal 201Tl accumulation. Two further false-positive studies consisted of angioma and epidural haematoma. Finally, SPET studies were normal in six patients with definite diagnosis of (reactive) gliosis (n = 3), Binswanger's encephalopathy (n = 1), postinfectious encephalopathy (n = 1) and multiple sclerosis (n = 1). In the patient population presented, sensitivity of 201Tl SPET for supratentorial brain tumours was 71.7% and specificity was 80.9%. Clinical information and control SPET studies in combination with early, 30-min and 3- to 4-h delayed imaging may be expected to improve on these figures. On the other hand it seems that, in addition to tumoral histology, the presence of tumours in the fossa posterior and small volumes contribute to the occurrence of fals

Topics: Adult; Aged; Aged, 80 and over; Brain Neoplasms; Cerebrovascular Disorders; Child; Diagnosis, Differential; False Negative Reactions; Female; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Retrospective Studies; Sensitivity and Specificity; Technetium Tc 99m Exametazime; Technetium Tc 99m Sestamibi; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon

Sixteen patients with primary brain tumours were examined on average eight years after treatment with surgery or whole brain irradiation using standard clinical assessment, CT, a neuropsychological test battery, and single photon emission CT (SPECT) with 99mTc-exametazime. Seventeen lesions were discovered on inspection of SPECT images, 11 with x-ray CT. Quantitative assessment of tracer uptake compared with 16 matched healthy volunteers was consistent with the presence of lesions. Measurement of uptake in brain regions of the hemisphere not containing the primary tumour still showed significant reductions in patients. This may be due to remote direct effects of the tumour or, more likely, to the whole brain irradiation received. Psychometric performance on most tests was significantly impaired in the patient group and was correlated with abnormalities of tracer uptake to relevant brain regions.

Topics: Adult; Aftercare; Brain Diseases; Brain Neoplasms; Case-Control Studies; Cranial Irradiation; Craniotomy; Female; Humans; Male; Matched-Pair Analysis; Middle Aged; Neuropsychological Tests; Organotechnetium Compounds; Oximes; Psychometrics; Psychomotor Performance; Survivors; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

High-grade astrocytoma represents the most common primary malignant brain tumour in the adult, and is associated with high morbidity and mortality rates. The aim of this study was to investigate the prognostic value of 99Tcm-hexamethylpropyleneamine oxime (HMPAO) brain single photon emission computed tomography (SPECT) in predicting neurological function and tumour therapy response after surgical resection of astrocytoma. The correlation between 99Tcm-HMPAO studies and other noninvasive methods [computed tomography (CT), magnetic resonance imaging (MRI) and 201Tl (SPECT)] was evaluated. The clinical population included 21 patients with previous surgical debulking of astrocytoma. All patients were evaluated with 99Tcm-HMPAO brain SPECT. Seven patients, who suffered progressive clinical deterioration after radiotherapy, underwent dual-isotope SPECT imaging with 201Tl and 99Tcm-HMPAO. Neurological examinations and CT were performed in all patients. Magnetic resonance imaging was performed in seven patients. Prior to radiotherapy and/or chemotherapy, the patients with neurological improvement during the follow-up evaluation commonly showed less intense abnormal 99Tcm-HMPAO uptake than the patients without neurological improvement. In addition, after therapy none of the former patients had increased 99Tcm-HMPAO uptake. Most patients without neurological improvement had evidence of high focal uptake. Computed tomography and MRI usually demonstrated pathological contrast enhancement regardless of the presence or absence of improvement of neurological function. Foci of high 201Tl accumulation were observed on SPECT images in five patients. In four of these patients, the 99Tcm-HMPAO was greater than in normal brain, and in two patients the 99Tcm-HMPAO uptake was lower than in normal brain. One patient with decreased 99Tcm-HMPAO uptake in a medium-sized lesion had a normal 201Tl study. Our hypothesis that 99Tcm-HMPAO SPECT may be useful for providing prognostic information after surgical debulking of astrocytoma seems to be promising. Further studies are needed to document this new important role of 99Tcm-HMPAO SPECT.

Topics: Adolescent; Adult; Aged; Astrocytoma; Brain Neoplasms; Female; Glioblastoma; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Organotechnetium Compounds; Oximes; Prognosis; Technetium Tc 99m Exametazime; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

High-resolution, non-invasive, 3D-imaging techniques would greatly benefit the investigation of the localization properties of tumor-specific radiopharmaceuticals in laboratory animals. The present study reports how pinhole SPECT can be applied to tumor localization studies in small laboratory animals to provide high resolution SPECT images in vivo. Pinhole SPECT was performed using a rotating scintillation camera, equipped with a pinhole collimator. The sensitivity of a 2 mm diameter collimator at 45 mm from the source is 90 cps/MBq for 99mTc. The planar spatial resolution at a 45 mm distance is 2.2 mm. The transaxial spatial resolution, with a distance of 45 mm between the collimator aperture and the axis of rotation, is 3.1 mm. For SPECT imaging, spatial linearity is preserved across the usable field-of-view. The major advantage of the high resolution properties of pinhole tomography is demonstrated by the enhanced lesion-to-normal-brain uptake ratio achieved on tomographic slices as compared to planar images. For example, 201Tl tumor-to-normal-brain uptake ratios of 1.1 to 1.3 observed on planar images, corresponded to ratios ranging from 3.2 to 3.7 on the SPECT slices. Examples of the activity distributions of two radiopharmaceuticals in tumor and in normal brain for sagittal and coronal images are given. In all cases, tumors are clearly delineated on the pinhole SPECT slices. The present study shows that pinhole SPECT performed with standard SPECT instrumentation can give high spatial resolution images, with a FWHM approximately 3 mm and a sensitivity approximately 100 cps/MBq for 99mTc.

Topics: Animals; Brain Neoplasms; Glioma; Organotechnetium Compounds; Oximes; Radioimmunodetection; Rats; Rats, Inbred F344; Sensitivity and Specificity; Technetium Tc 99m Exametazime; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon

Supraophthalmic intraarterial chemotherapy has not become popular due to a high incidence of damage to the normal brain and eye. This damage is due to inhomogeneous distribution of the agent secondary to streaming and other flow-related phenomena. To try to minimize this complication, the authors developed a catheter and studied different infusion techniques. A 4.5-F catheter tapered to 2.5 F was used to perform supraophthalmic intraarterial chemotherapy in 26 patients with malignant gliomas. Forty-one of 45 catheterizations were successful. In 17 patients (20 procedures), technetium-99m hexamethyl-propyleneamine oxime (HMPAO) was then injected through the catheter and single photon emission computed tomography was performed to assess the cerebral distribution of the radiopharmaceutical with either a pulsatile or continuous infusion technique. Diffuse and relatively homogeneous distribution of Tc-99m HMPAO was observed with fast pulsatile infusion (10 of 10 procedures); however, inhomogeneous distribution was mostly seen with slow continuous infusion (eight of 10 procedures).

Topics: Adolescent; Adult; Brain Neoplasms; Catheterization; Child; Glioma; Humans; Infusions, Intra-Arterial; Infusions, Intravenous; Middle Aged; Organotechnetium Compounds; Oximes; Radionuclide Imaging; Technetium Tc 99m Exametazime

In order to assess the cerebral distribution of intracarotid chemotherapy, 17 postoperative patients with brain tumor underwent brain SPECT obtained by intraarterial infusion of 18.5 MBq of 99mTc-HMPAO. Injection methods were continuous (5.0 ml/min) or pulsatile infusion with supraor infraophthalmic catheterization. The findings obtained by brain SPECT were frequently different from those of angiography and/or DSA. In supraophthalmic catheterization with continuous infusion, only 2 of 10 studies (20%) had homogeneous distribution and 5 of them (50%) had maldistribution of 99mTc-HMPAO which appears in association with laminar flow effect. The remaining 3 studies showed localized distribution (two: tumor localization, one: healthy brain localization). On the other hand, all of 5 studies with pulsatile infusion had homogeneous distribution of 99mTc-HMPAO. In infraophthalmic catheterization, all but one of 5 studies had homogeneous distribution with continuous infusion. These results suggest that pulsatile infusion may be effective in eliminating maldistribution of 99mTc-HMPAO in supraophthalmic catheterization. In conclusion, we are convinced that 99mTc-HMPAO is a useful intraarterial agent for assessing cerebral distribution of intracarotid chemotherapy.

Topics: Adolescent; Adult; Antineoplastic Combined Chemotherapy Protocols; Brain; Brain Neoplasms; Carotid Artery, Internal; Etoposide; Female; Humans; Infusions, Intra-Arterial; Male; Middle Aged; Nimustine; Organotechnetium Compounds; Oximes; Pulsatile Flow; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

SPECT scanning with Tl-201 and Tc-99m offers a unique, inexpensive functional imaging modality to combine with CT stereotactic craniotomy for guiding resection of necrosis and/or tumour in patients treated with escalated doses of radiation (> 6000 cGy) by either brachytherapy or radiosurgery. Thirty-two cases were analyzed, with a detailed description of the imaging and operative techniques.

Topics: Astrocytoma; Brachytherapy; Brain; Brain Neoplasms; Combined Modality Therapy; Cranial Irradiation; Craniotomy; Follow-Up Studies; Glioma; Humans; Image Processing, Computer-Assisted; Necrosis; Neoplasm Recurrence, Local; Organotechnetium Compounds; Oximes; Radiation Injuries; Radiosurgery; Radiotherapy Dosage; Reoperation; Software; Stereotaxic Techniques; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Tumor perfusion and oxygenation status have been suggested as factors which may influence treatment outcome in cancer patients. Nuclear medicine assays of tumor perfusion [99mTc-hexamethylpropylenamine oxime (HMPAO)] and tumor hypoxia [123I-iodoazomycin arabinoside (IAZA)] have recently been developed and described. We report on measurements of perfusion and oxygenation status of 27 tumors in 22 patients using these probes. An inverse correlation between tumor uptake of HMPAO and IAZA was measured (p < 0.05), with severe perfusion deficit usually associated with an increased uptake of the hypoxic marker. This trend was observed for limited stage small-cell lung carcinoma, squamous-cell carcinoma of the head and neck, soft-tissue sarcoma, brain metastases from small-cell lung carcinoma and adenocarcinoma of the prostate as a group, but not for glioblastoma multiforme. Whereas each imaging agent can yield information about the physiological status of tumor and normal tissue, the information resulting from their combined use could be important in cancer therapy.

Topics: Brain Neoplasms; Carcinoma, Small Cell; Carcinoma, Squamous Cell; Cell Hypoxia; Female; Glioblastoma; Head and Neck Neoplasms; Humans; Iodine Radioisotopes; Lung Neoplasms; Male; Nitroimidazoles; Organotechnetium Compounds; Oximes; Sarcoma; Soft Tissue Neoplasms; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

We compared the value of gadolinium-enhanced first-pass MRI perfusion studies and HMPAO-SPECT for the assessment of regional cerebral blood flow in a prospective study of 23 intracranial tumour patients. In five tumours with homogeneous hypoperfusion and eight tumours with homogeneous hyperperfusion, tumour blood flow patterns in MRI and HMPAO-SPECT were similar. By contrast, in ten patients with inhomogeneous tumour blood flow pattern only MRI was able to differentiate between tumour areas with no or low flow, tumour tissue with high flow, and perifocal oedema with reduced flow. In HMPAO-SPECT, these inhomogeneous tumours were represented as areas of homogeneously reduced tracer retention corresponding to different tumour constituents and perifocal oedema. In conclusion, the high spatial resolution of MRI enables a detailed analysis of tumour blood flow.

Topics: Brain; Brain Neoplasms; Cerebrovascular Circulation; Color; Contrast Media; Evaluation Studies as Topic; Gadolinium; Gadolinium DTPA; Humans; Magnetic Resonance Imaging; Organometallic Compounds; Organotechnetium Compounds; Oximes; Pentetic Acid; Technetium; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

The demonstration and accurate localization of intracerebral mass lesions are commonly performed with computerized tomography (CT), which often cannot determine the nature of the lesion. As an aid in the differential diagnosis between brain abscess and neoplasm, the authors have evaluated both 99mTc-hexamethylpropyleneamine oxime (99mTc-HMPAO) leukocyte scintigraphy and the serum C-reactive protein level. Of 23 patients with intracranial mass lesions, 22 individuals showed ring-like contrast enhancement on CT scans; the one exception was a patient treated for a meningioma who had a negative CT scan despite clinical suspicion of intra- or extracranial abscess. The final diagnosis was invariably established by microscopic examination of tissue specimens. In 10 patients the final diagnosis was brain abscess; the other 13 patients harbored a brain neoplasm (glioma in nine, astrocytoma in one, and metastasis in three). The 99mTc-HMPAO leukocyte scintigraphy detected all cases of abscess. There were no false-positive results. An elevated C-reactive protein level (> 13 mg/liter) was found in all but one patient with abscess and in three patients with neoplasm; two of these three patients had dental root infections which could account for the elevation of C-reactive protein. It is concluded that 99mTc-HMPAO leukocyte scintigraphy should be performed when there is a possibility that a brain abscess may exist. Any steroid treatment should be discontinued for 48 hours prior to leukocyte scintigraphy. Also, C-reactive protein determination should be performed and is useful even when steroids are given.

Topics: Adolescent; Adult; Aged; Brain Abscess; Brain Neoplasms; C-Reactive Protein; Diagnosis, Differential; Female; Humans; Leukocytes; Male; Middle Aged; Organotechnetium Compounds; Oximes; Radionuclide Imaging; Technetium Tc 99m Exametazime

Dual isotope brain SPECT was performed in a patient with recurrent brain tumor (grade II astrocytoma). In this case, a good coregistration of brain perfusion and tumor images was obtained because Tc-99m HMPAO and the Tl-201 chloride imaging were done simultaneously using a Triad SPECT unit. This method might play an important clinical role in the evaluation of patients with recurrent brain tumors.

Topics: Adult; Astrocytoma; Brain Neoplasms; Humans; Male; Neoplasm Recurrence, Local; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon

Deteriorating clinical status after high-dose radiation therapy for high-grade gliomas may be due to radiation changes or may signal recurrent or residual tumor mass. The two conditions cannot be distinguished reliably by computerized tomography (CT) or magnetic resonance (MR) imaging. The authors assessed the ability of sequential thallium-201 chloride (201Tl) and technetium-99m hexamethylpropylene amine oxime (99mTc HMPAO) single-photon emission CT (SPECT) to distinguish tumor recurrence from radiation changes after high-dose (greater than or equal to 600 cGy) radiation therapy for malignant gliomas. Preoperative tumor/nontumor uptake ratios were analyzed in 32 patients and correlated with the presence of gross tumor at the time of reoperation. In 12 of 13 patients with 201Tl tumor/scalp ratios of 3.5 or greater, recurrent tumor was present. The authors found 99mTc HMPAO SPECT to be useful for identifying the absence of solid tumor recurrence in patients with low to moderate 201Tl uptake (ratio 1.1 to 3.4) and low perfusion to that site. In 11 of 12 patients with 99mTc HMPAO tumor/cerebellum ratios of 0.50 or less, no recurrent tumor mass was present. Three of seven patients with 201Tl ratios of 3.4 or less and 99mTc HMPAO ratios of 0.51 or more had recurrent tumor found at surgery; thus the test was not predictive in this group. It is concluded that the use of sequential 201Tl and 99mTc HMPAO SPECT accurately identifies the presence of tumor recurrence versus radiation changes in most patients with high-grade astrocytomas who have undergone tumor resection and high-dose radiation therapy.

Topics: Adult; Aged; Aged, 80 and over; Brain Neoplasms; Female; Glioma; Humans; Male; Middle Aged; Models, Structural; Neoplasm Recurrence, Local; Observer Variation; Organotechnetium Compounds; Oximes; Predictive Value of Tests; Technetium Tc 99m Exametazime; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon

Topics: Brain; Brain Neoplasms; Choristoma; Humans; Magnetic Resonance Imaging; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Sequential thallium-201-chloride and technetium-99m-hexamethylpropyleneamine oxime single-photon emission computed tomography (SPECT) images were obtained in a patient with extracranial metastatic glioblastoma multiforme. Thallium-201 uptake was high (three times the scalp background) in all pathologically confirmed extracranial metastases and moderate (1.6 times scalp background) intracranially, where most biopsy specimens showed gliosis with scattered atypical astrocytes. Technetium-99m-HMPAO uptake was decreased intracranially in the right frontal and parietal lobes which had been irradiated. It was also decreased in one well-encapsulated scalp lesion and high in another scalp mass with less defined borders. Possible mechanisms of tumor uptake of these agents are reviewed.

Topics: Adult; Brain Neoplasms; Female; Glioblastoma; Humans; Organotechnetium Compounds; Oximes; Scalp; Skin Neoplasms; Technetium Tc 99m Exametazime; Thallium; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon

Technetium-d, HMPAO SPECT was performed in 70 patients suffering from intracerebral tumors of various histologic types (glioma n = 30, meningioma n = 19, metastases n = 10, angioma n = 3, neuroma n = 2, lymphoma n = 2, neurocytoma n = 1, epidermoid n = 1, gliosis n = 1, cholesteatoma n = 1). Tumor classification was histologically verified in all subjects except in two cases with inoperable angiomas. SPECT was performed under resting state conditions with a dual-head rotating camera (SIEMENS ZLC 37) following intravenous injection of 18-25 mCi 99mTc-d, 1-HMPAO. Regional tracer deposit was expressed in terms of a cerebellar index (CBI). Significantly higher regional HMPAO uptake was found in meningiomas when compared with gliomas of different malignancy (ANOVA p less than 0.05). Within gliomas, regional uptake increased with malignancy (n.s.). In 23 patients, a total of 32 tumor specimens were obtained for histochemical analysis of glutathione (GSH) content using high-pressure liquid chromatography. A significant correlation (least square method, p less than 0.001) between CBIs and GSH values was found, supporting the hypothesis that GSH is the predominant factor for the conversion of the lipophilic complex to hydrophilic derivates.

Topics: Adult; Aged; Aged, 80 and over; Brain Neoplasms; Cerebrovascular Circulation; Female; Glioma; Glutathione; Hemangioma; Humans; Male; Meningeal Neoplasms; Meningioma; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Topics: Brain Neoplasms; Cerebrovascular Circulation; Glutathione; Humans; Organotechnetium Compounds; Oximes; Radionuclide Imaging; Technetium Tc 99m Exametazime

Topics: Adult; Aged; Brain; Brain Neoplasms; Humans; Lymphoma; Male; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Imaging findings of morphology and regional cerebral blood flow in two patients suffering from epileptic seizures are presented. CT and MRI revealed heterotopic gray matter as a probable structural correlate, causing the seizure disorder. 99mTc hexamethyl-propylenamine oxime (HM-PAO) SPECT demonstrated focally increased regional cerebral blood flow in both patients in the areas of their heterotopic lesions. Heterotopic and orthotopic gray matter seem to have similar features in terms of regional perfusion. A focally increased brain perfusion in interictal epileptic patients may indicate an underlying migration anomaly.

Topics: Adult; Brain Neoplasms; Cerebrovascular Circulation; Choristoma; Epilepsy; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

The aim of the present study was to evaluate the predictive value of interictal single-photon emission computed tomography (SPECT) using technetium-99m-labeled hexamethyl propyleneamine oxime (HMPAO) for the outcome after temporal lobectomy in patients with complex partial seizures. Out of 40 patients, 21 underwent right-sided and 19 left-sided temporal lobectomy. EEG and CT/MRI were primarily used to select the side of surgery. SPECT results correlated with temporal lobectomy in 68% of the patients. After surgical intervention, memory function was tested for both sides. Following left-sided temporal lobectomy, verbal memory was impaired in 8% of the patients, if SPECT agreed with the side selected for surgery, but in 83%, if it diverged from it. In the present study, there was no relationship between SPECT concordance with the side of temporal lobectomy and outcome as to seizure frequency and non-verbal memory. We conclude that preoperative interictal HMPAO/SPECT can contribute to the prediction of postoperative verbal memory function and that this method should be considered for use prior to temporal lobectomy.

Topics: Adolescent; Adult; Brain Neoplasms; Child; Epilepsy, Temporal Lobe; Female; Gliosis; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Prognosis; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed, Single-Photon

The paper is concerned with the results of single-photon emission tomography and gamma-topography in patients with cerebral tumors, cerebral circulatory disorders and pathology of the liquor system. Tomographic investigation was shown to enhance the accuracy and reliability of the detection of cerebral tumors. Single-photon emission computerized gamma-tomography (SPECT) permitted the detection of structural and morphological cerebral changes in disturbed cerebral circulation of various etiology. SPECT together with computerized tomography and radionuclide cisternography was shown to be an auxiliary method for visualization of the cerebral cisterns. Radionuclide tomographic images as compared to gamma-topographic findings of the brain possessed a high statistical significance and good resolution.

Topics: Adult; Brain; Brain Neoplasms; Cerebrospinal Fluid; Cerebrovascular Disorders; Evaluation Studies as Topic; Female; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Sodium Pertechnetate Tc 99m; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Nineteen patients with biopsy-proven cerebral gliomas were studied with 99mTc-HMPAO single photon emission tomography (SPECT) imaging and X-ray computed tomography (CT). The uptake of 99mTc-HMPAO was correlated with tumour size and morphology as shown by X-ray CT, and overall patient survival. It appears that uptake of 99mTc-HMPAO is associated with larger, ill-defined tumours and was an adverse factor in patient survival. In those tumours with normal or increased uptake, 99mTc-HMPAO imaging is useful in distinguishing the tumour margin from surrounding oedema.

Topics: Brain Neoplasms; Glioma; Humans; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

The purpose of the presented study was to determine the diagnostic value of correlated EEG and SPECT findings in patients with CNS-manifestations of AIDS. Ten HIV 1 infected patients had been examined. Diagnoses: meningitis (2 x), lymphoma (2 x), necrotizing encephalitis (1 x), toxoplasmosis (7 x) (Some patients had more than one diagnosis). Unenhanced and Gd-DTPA enhanced MR, 99mTc-HM-PAO SPECT and clinical EEG were compared. In 9/10 patients MR demonstrated intracranial lesions. In one patient with necrotizing encephalitis (not detected by MR), SPECT revealed an inhomogeneous cerebral perfusion. Only lymphoma was hyperperfused. Toxoplasmic lesions-when detectable by SPECT-were hypoperfused. Reduced rCBF was also seen in brain regions not affected directly, but functionally associated to altered areas. EEG revealed diffuse signs such as slowing in patients with brain atrophy, but also in those patients with lesions of basal ganglia and thalamus. Focal signs in the EEG were in concordance with imaging findings in only 2/10 patients. In 4/10 patients foci even adjacent to the cortex - as shown by MR - remained undetected by EEG. One patient with an active toxoplasmosis had sharp waves over the affected region. The parallel application of the three methods as suggested in this paper appears useful not only for scientific purposes. In most cases, this procedure provides relevant diagnostic information. It is recommended for AIDS-patients with CNS manifestations of unknown etiology.

Topics: Acquired Immunodeficiency Syndrome; Adult; Brain; Brain Diseases; Brain Neoplasms; Electroencephalography; Encephalitis; HIV-1; Humans; Lymphoma; Magnetic Resonance Imaging; Male; Meningitis; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed; Toxoplasmosis

A study was made of the cerebral hemodynamics by assessing the distribution in single-photon emission computerized tomography with 99mTc-hexamethyl-propyleneminoxyne in health using a Testascan in 9 standard slices. The whole set of tomographic slices was conventionally divided into 3 levels. For better orientation in gamma-tomographic images, pictures were presented where in addition to scintigrams a morphological scheme of the cerebral parts with the marked parts perfused by cerebral arteries, was given.

Topics: Brain; Brain Neoplasms; Cerebrovascular Circulation; Cerebrovascular Disorders; Contrast Media; Hemodynamics; Humans; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Topics: Adult; Aged; Aged, 80 and over; Brain Neoplasms; Cerebrovascular Circulation; Female; Glioma; Humans; Iodobenzenes; Lymphoma; Male; Meningeal Neoplasms; Meningioma; Middle Aged; Organotechnetium Compounds; Oximes; Regional Blood Flow; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

The cerebral uptake of 99Tcm-hexamethylpropyleneamine oxime (99Tcm-HMPAO) as measured with the use of single photon emission computed tomography (SPECT) was studied in 66 patients with various types of brain tumours and quantified by tumour-to-cerebellum ratios. The uptake of 99Tcm-HMPAO by gliomas and meningiomas showed wide ranges of values. There were no significant differences among primary malignant gliomas (0.75 +/- 0.27, n = 25), recurrent malignant gliomas (0.81 +/- 0.25, n = 14) and benign gliomas (0.77 +/- 0.21, n = 9). Compared to gliomas, meningiomas exhibited a significantly higher 99Tcm-HMPAO uptake (1.14 +/- 0.31, n = 13, p less than 0.001) while the remaining four patients with tumours of various histopathology showed a low 99Tcm-HMPAO uptake. Three of the 66 patients were scanned immediately and again 2 h after injection and they revealed a decrease in tumour activity. No changes in the pattern of uptake were observed in two patients with gliomas which were studied before and after intra-arterial chemotherapy, but a decrease in tumour uptake was found in the glioma patient who was studied before and after radiotherapy. The results obtained with 99Tcm-HMPAO SPECT are in agreement with those on regional cerebral blood flow (rCBF) in brain tumours reported in the literature.

Topics: Brain Neoplasms; Glioma; Humans; Meningioma; Organometallic Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed

A preliminary study of the distribution of the 99mTc complex of hexamethylpropylene amine oxime (HM-PAO) in 12 patients with brain neoplasms before, during, and after radiotherapy has been performed. Untreated brain tumors were found to exhibit a range of 99mTc-HM-PAO uptake, varying from areas of markedly increased isotope activity to photopenic areas, when compared to normal brain tissue. A ratio of 99mTc-HM-PAO tumor uptake to contralateral normal tissue uptake was calculated prior to and during radiotherapy. This ratio tended to return towards unity in lesions responding to therapy. A predictable alteration in whole brain 99mTc-HM-PAO uptake during radiotherapy was not demonstrated. Unlike the radiolabeled amines, 99mTc-HM-PAO localizes in primary tumors, probably indicating that its uptake mechanism is independent of non specific amine receptors. 99mTc-HM-PAO may be useful in the study of brain tumor physiology and response to therapy.

Topics: Adult; Aged; Brain Neoplasms; Carcinoma, Bronchogenic; Carcinoma, Small Cell; Female; Glioma; Humans; Lung Neoplasms; Male; Middle Aged; Organometallic Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed

Topics: Adult; Aged; Amphetamines; Brain Neoplasms; Female; Glioblastoma; Hemangioma, Cavernous; Hemangiosarcoma; Humans; Iodine Radioisotopes; Iofetamine; Male; Meningeal Neoplasms; Meningioma; Middle Aged; Organometallic Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed; Xenon Radioisotopes

Topics: Amphetamines; Brain Neoplasms; Glioblastoma; Humans; Iodine Radioisotopes; Iofetamine; Male; Middle Aged; Organometallic Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed

In 10 patients with malignant gliomas, the intracerebral distribution of [99mTc]-hexamethylpropylene-amine oxime [( 99mTc]-HM-PAO) was studied with single photon emission computed tomography (SPECT) in comparison with C15O2 steady-state inhalation technique to measure cerebral blood flow using positron emission tomography (PET). In all instances, the cerebral [99mTc]-HM-PAO distribution was comparable with the regional pattern of cerebral blood flow (rCBF) observed with PET. This was confirmed by a significant correlation of tumor to cortex and tumor to white matter ratios between these two experimental methods. However, the contrast between high and low activity regions in the SPECT scans was significantly less than that in the PET scans. Contrast enhancement of the SPECT scans was accomplished using a correction formula proposed by Lassen.

Topics: Brain Neoplasms; Carbon Dioxide; Cerebrovascular Circulation; Glioblastoma; Humans; Organometallic Compounds; Oximes; Oxygen Radioisotopes; Technetium; Technetium Tc 99m Exametazime; Tomography, Emission-Computed

Topics: Adult; Aged; Amphetamines; Astrocytoma; Brain Neoplasms; Female; Glioma; Humans; Iofetamine; Male; Meningioma; Organometallic Compounds; Oximes; Pentetic Acid; Technetium Tc 99m Exametazime; Technetium Tc 99m Pentetate; Tomography, Emission-Computed

Topics: Blood Flow Velocity; Brain; Brain Neoplasms; Cerebrovascular Circulation; Cerebrovascular Disorders; Humans; Organometallic Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed

99mTc-hexamethyl-propyleneamine-oxime (HM-PAO) was developed as a radiotracer of regional cerebral blood flow (rCBF) with SPECT. THe purpose of this study was to investigate if HM-PAO is able to trace rCBF in primary brain tumors. In 10 patients with glioblastoma grade IV the intracerebral distribution of HM-PAO was studied in comparison with C15O2 steady state inhalation technique and PET for rCBF evaluation. In all instances the cerebral HM-PAO distribution was comparable with rCBF pattern as confirmed by a significant correlation of tumor to cortex ratios. The results indicate the clinical usefulness of HM-PAO for tracing rCBF in brain tumors.

Topics: Brain Neoplasms; Cerebrovascular Circulation; Humans; Organometallic Compounds; Oximes; Technetium; Technetium Tc 99m Exametazime; Tomography, Emission-Computed

Topics: Adult; Aged; Brain; Brain Neoplasms; Cerebrovascular Circulation; Female; Humans; Male; Migraine Disorders; Organometallic Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed

Topics: Adult; Aged; Amphetamines; Brain; Brain Neoplasms; Cerebrovascular Circulation; Female; Humans; Intracranial Arteriovenous Malformations; Iodine Radioisotopes; Iofetamine; Male; Middle Aged; Organometallic Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed; Xenon Radioisotopes

The cerebral and cerebellar distribution of 99mTc-(d,1)-hexamethylpropyleneamine oxime (HM-PAO) was investigated by means of a rotating gamma camera in 12 patients with cerebral glioma. Using the corresponding contralateral region as control, reduced uptake of HM-PAO in the tumor region was demonstrated in 10 of the 12 patients. Reduced blood flow in a brain area remote from a circumscribed lesion reflects reduced activation following the interruption of afferent nervous pathways. Reduced HM-PAO uptake indicative of such diaschisis was demonstrated in the visual cortex contralateral to homonymous hemianopia in the two patients with this deficit. In the three patients with the most marked hemiparesis, the cerebellar hemisphere contralateral to the tumor showed significantly reduced HM-PAO uptake indicative of crossed cerebellar diaschisis. SPECT using commonly available gamma cameras and 99mTc-HM-PAO seems capable of depicting reduced flow in functionally inactivated brain areas, and may be clinically interesting as an alternative to more specialized techniques for the investigation of local cerebral blood flow.

Topics: Adult; Astrocytoma; Brain; Brain Neoplasms; Cerebellum; Female; Glioma; Humans; Male; Middle Aged; Organometallic Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed; Tomography, X-Ray Computed; Visual Cortex