technetium-tc-99m-exametazime and Astrocytoma

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

Mutism is an infrequent and transitory complication observed following posterior fossa surgery. Patients become mute in the immediate postoperative period, with restoration of speech within a few weeks in the absence of additional neurological alterations. The anatomical structures thought to be involved are the connections between the cerebellar dentate nucleus, the ventrolateral nucleus of the contralateral thalamus and the supplementary motor area. In an attempt to understand the pathophysiology of this syndrome, and to depict the perfusion of different brain areas semiquantitatively, in two children who had become mute after posterior fossa surgery we performed a Tc99M-HM-PAO SPECT study during the period of mutism and again when normal speech had returned. In one patient, who had a left cerebellar astrocytoma, the SPECT study showed a marked reduction of cerebral perfusion in the right fronto-parietal region, and in the other, who had a medulloblastoma, a left fronto-temporo-parietal perfusion alteration was observed. When the patients regained normal speech, the follow-up SPECT studies revealed normalization of the cerebral perfusion. This study demonstrates the occurrence of a focal dysfunction of cerebral perfusion in children with cerebellar mutism after posterior fossa surgery. These observations are useful in extending our understanding of the pathophysiology of this postoperative clinical syndrome.

Topics: Adolescent; Astrocytoma; Cerebellar Neoplasms; Cerebrovascular Circulation; Child, Preschool; Cranial Fossa, Posterior; Humans; Magnetic Resonance Imaging; Male; Medulloblastoma; Mutism; Postoperative Complications; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

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

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

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

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

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

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

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