Evaluation of Glioma with Thallium-201 Brain SPECT : The Correlation with 1H MR Spectroscopy and Pathology / 대한핵의학회잡지

PURPOSE: Thallim-201 (201Tl) brain SPECT and proton (1H) magnetic resonance spectroscopy (MRS) have been used to evaluate tumor grade and viability of glioma. We assessed the correlations between 201Tl brain index or spectrum of metabolites of 1H MRS and grade of glioma or histopathologic findings. MATERIALS AND METHODS: We studied 17 patients (4 astrocytoma, 7 anaplastic astrocytoma and 6 glioblastoma). On 201Tl Brain SPECT, 201Tl index was measured as the ratio of average counts for region of interest to those for the contralateral normal brain. On 1H MRS, we calculated choline (Cho) /creatine (Cr) ratio and N-acetylaspartate (NAA)/Cr ratio in ROI defined as tumor center. Histopathologic findings were graded by Ki-67 index, cellularity, mitosis, pleomorphism, necrosis and endothelial proliferation. An unpaired t test and statistical correlations were performed to evaluate these data. RESULTS: Tl-index showed the best correlation with Ki-67 index (p<0.01), less correlations with cellularity, mitosis, and endothelial proliferation, but no correlation with results of MRS, pleomorphism, or necrosis. The findings of MRS did not correlate with all of the above. The cases of glioblastoma demonstrated a higher Tl-index, Cho/Cr ratio, Ki-67 index and lower NAA/Cr ratio, albeit without statistical significance. CONCLUSION: Even though 201Tl brain SPECT did not correlate directly with grade of malignancy, it may still be useful in determining biological aggressiveness of tumor and prognosis of patients because it correlated well with Ki-67 index, a growth fraction of glioma, cellularity, mitosis and endothelial proliferation.

Preoperative Evaluation of Brain Lesion with 201Tl Brain SPECT: Is It Useful to Differentiate Benign and Malignant Lesions? / 대한핵의학회잡지

PURPOSE: Thallim-201 (201Tl) brain SPECT, which can represent cellular activity of brain lesions, may provide more useful information in differentiating between benign and malignant brain lesions more so than CT or MRI, that merely represents anatomic changes or breakdown of blood brain barrier. We used 201Tl brain SPECT prospectively to evaluate the utility of 201Tl-indices as an indicator of benign or malignant lesions. MATERIALS AND METHODS: We studied 28 patients. There were 13 cases of benign lesions (3: nonspecific benign lesion, 3: meningioma, 2: low grade glioma, 1: tuberculoma, central neurocytoma, hemangioblastoma, radiation necrosis, and choroid plexus papilloma) and 15 cases of malignant lesions (6: glioblastoma multiforme, 5: anaplastic glioma, 2: medulloblastoma, 1: metastasis and lymphoma). In all patients, CT and/or MRI were obtained and then 201Tl brain SPECT was obtained with measuring mean 201Tl index and peak 201Tl index. An unpaired t-test was performed to compare the 201Tl-indices and pathologic diagnoses to evaluate the utility of 201Tl-indices as an indicator of benign or malignant lesions. RESULTS: There were no statistically significant difference in 201Tl-indices between benign and malignant brain lesions (P>0.05). CONCLUSION: These results demonstrated that we could not use 201Tl indices on brain SPECT alone as an indicator of benign or malignant brain lesions.

Staged Decompression of Chiari Malformation Associated with Basilar Invagination: A Case Report

The staged decompression(posterior and anterior) of foramen magnum was performed in the patient with Chiari I malformation associated with basilar invagination. Three years prior to admission, the patient was admitted due to ataxia and dysmetria. After the posterior decompression of foramen magnum, the patient's cerebellar sign improved significantly. But spastic gait disturbace was noted two years later. We performed a transoral anterior decompression to relieve brain stem compression, and an occipitocervical fusion with contoured rod to prevent possible instability. Following the operation, the spasticity improved. The authors believe this sets the successful staged decompression of Chiari I malformation associated with basilar invagination.