Technetium Tc99m Tetrofosmin Single-Photon Emission CT for the Assessment of Glioma Proliferation

We read the interesting recent article by Kato et al1 concerning the assessment of gliomametabolic activity by positron-emission tomog-raphy (PET).1 The authors evaluated the type, grade, and prolifera-tion index of 95 primary glioma cases by simultaneous [18F] fluoro-deoxyglucose (18F-FDG), 11C-methionine (MET) and 11C-choline (CHO) PET. Their results in astrocytic tumors showed a significant correlation between all tracer uptake and both tumor grade and pro-liferation activity (as assessed by the Ki-67/Mib-1 immunohistologic index). Nonetheless, in oligodendrogliomas and inmixed oligoastro-cytic tumors, only CHO-PET demonstrated a significant correlation between tracer uptake and tumor grade. As regards visual image eval-uation, MET-PET was proved superior due to its insignificant uptake by normal brain tissue.1 The proliferation potential of gliomas is important for patient management and has significant prognostic implications. Its assess