technetium-tc-99m-exametazime and Glioma

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

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-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

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

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

A method for registering three-dimensional CT, MR, and PET data sets that require no special patient immobilization or other precise positioning measures was adapted to high-resolution SPECT and MRI and was applied in 14 subjects (five normal volunteers, four patients with dementia (Alzheimer's disease), two patients with recurrent glioblastoma, and three patients with focal lesions (stroke, arachnoid cyst and head trauma]. T2-weighted axial magnetic resonance images and transaxial 99mTc-HMPAO and 201Tl images acquired with an annular gamma camera were merged using an objective registration (translation, rotation and rescaling) program. In the normal subjects and patients with dementia and focal lesions, focal areas of high uptake corresponded to gray matter structures. Focal lesions observed on MRI corresponded to perfusion defects on SPECT. In the patients who had undergone surgical resection of glioblastoma followed by interstitial brachytherapy, increased 201Tl corresponding to recurrent tumor could be localized from the superimposed images. The method was evaluated by measuring the residuals in all subjects and translational errors due to superimposition of deep structures in the 12 subjects with normal thalamic anatomy and 99mTc-HMPAO uptake. This method for superimposing magnetic resonance and high-resolution SPECT images of the brain is a useful technique for correlating regional function with brain anatomy.

Topics: Alzheimer Disease; Arachnoid Cysts; Brain; Brain Injuries; Cerebrovascular Disorders; Glioma; Humans; Image Processing, Computer-Assisted; Magnetic Resonance Imaging; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; 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

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

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; 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

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