Thallium-201 single-photon emission computed tomographic and proton magnetic resonance spectroscopic characteristics of intracranial ganglioglioma: Three technical case reports

OBJECTIVE: The correlation between thallium-201 (²⁰¹TI) uptake, semiquantitative choline-containing compound values measured by proton magnetic resonance spectroscopy (¹H-MRS), and Ki-67 labeling indexes (LIs) was investigated in three gangliogliomas. METHODS: The early and delayed ²⁰¹TI indexes were calculated as the ratio of tumor to normal brain tissue uptake by ²⁰¹TI single-photon emission computed tomography. Single-voxel ¹H-MRS was performed to measure the levels of metabolites in the tumors. Ki- 67 LI was measured in the surgical specimens. RESULTS: All three gangliogliomas showed very high ²⁰¹TI uptake on both early and delayed images. ¹H-MRS demonstrated malignancy based on the high choline peak relative to the creatine and N-acetylaspartate peaks. Ki-67 LI was less than 1% in two gangliogliomas and 3.5% in an anaplastic ganglioglioma. CONCLUSION: Both ²⁰¹TI single-photon emission computed tomography and ¹H-MRS indicated malignancy, whereas Ki-67 LI indicated low growth activity. ²⁰¹TI single-photon emission computed tomography and ¹H-MRS of ganglioglioma might be affected by metabolic characteristics other than growth activity.