Pentavalent technetium-99m-dimercaptosuccinic acid [99mTc(V)-DMSA] brain SPECT versus proton magnetic resonance spectroscopy (1H-MRS) in assessment of glioma recurrence post radiotherapy

Objectives To assess the clinical value of TFF in pts studied for NTC

Methods The study included 24 glioma patients, previously operated upon and treated with radiotherapy. SPECT images were acquired 2 hours post 740 MBq of ^99mTc(v)-DMSA administration with a dual-head gamma camera. Tumor to normal (T/N) uptake ratio was calculated as: mean counts of tumor ROI (T) ÷ mean counts of normal mirror symmetric ROI (N). 1H-MRS was performed using a 1.5 T system equipped with a spectroscopy package. SPECT and 1H-MRS results were compared with pathology 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 patients. SPECT and 1H-MRS disagreed in 9 cases of recurrence (7diagnosed as positive for viable tumor by brain SPECT& 2 by 1H-MRS). SPECT and 1H-MRS sensitivity in detecting recurrence as compared with surgical biopsy or follow up was 88.8% and 61.1% respectively with an accuracy of 91.6% & 45.8% respectively.

Conclusions ^99mTc(V)-DMSA brain SPECT is more accurate compared to 1H-MRS in detecting and differentiating glioma recurrence from post radiation changes.