LETTER TO THE EDITOR The use of PET scan in glioblastoma multiforme

An interesting recent article by Potzi et al. addressed the value of positron emission tomography (PET) by the tracers carbon-11-methionine (11C-MET) and fluorine-18-fluorode-oxyglucose (18 F-FDG) in the follow-up of patients suffering from glioblastoma multiforme [1]. The authors studied 28 cases with both FDG- and MET-PET, after their initial treatment; they found no correlation between tumoral uptake of either tracer and survival. Furthermore, both PET tracers provided inconclusive results with reference to the discrimination be-tween tumor recurrence and radiation injury [1]. Apart from PET, conventional functional brain imaging by single-photon emission computed tomography (SPECT) has also been evaluated in gliomas. Thallium-201 (201Tl) and several technetium-99m-labeled compounds have been stud-ied. The latter are advantageous over 201Tl, due to the 140 ke