Introduction: The differentiation between recurrent tumor progression and radiationtherapy effects in subject previously treated for glioma is problematic Computed tomography and magnetic resonance imaging offer imperfect discrimination of tumorviability and radionecrosis. Both brain SPECT and proton MR spectroscopy may be useful to differentiate between tumor recurrence and radiation necrosis The aim of this study was to compare 99mTc-penta (v)DMSA brain SPECT versus protonmagnetic resonance spectroscopy (1H-MRS) findings for detection of recurrent glioma in 24 patients after radiation therapy. METHODS: Both exams were performed on 24 glioma patients, previously operated upon and treated withradiotherapy, SPECT images were acquired 3 hours after 40 MBq (20 mci) of Tc99m DMSA administration with a dual-head gamma camera. T/N uptake ratio was calculated between a tumor ROI (T) and a normal mirror symmetric ROI (N). 1HMRS was performed using a 1.5 T system equipped with a spectroscopy package.SPECT and 1H-MRS data were compared with pathology after new surgery or with follow-up. RESULTS: SPECT and 1H-MRS showed recurrence in 9 patients (confirmed by biopsy or follow up) and both were negative in 6. SPECT and 1H-MRS disagreed in 9 cases of recurrence (7diagnosed by as positive viable tumor as brainSPECT, 2 by 1H-MRS). SPECT and 1H-MRS sensitivity in detecting recurrence as compared with surgical biopsy or follow up was 88.8%,61.1% respectively withaccuracy 91.6%, 45.8.% respectivelyCONCLUSIONS Brain SPECT had higher detection in differentiating tumor recurrence and post radiation changes as compared to 1H-MRS and in the follow-up of treated glioma.