PET Versus SPECT in Distinguishing Radiation Necrosis from Tumor Recurrence in the Brain

Two cases of postsurgical brain tumor evaluation in which MRI was inconclusive are discussed. Functional imaging techniques, such as FDG-PET and {sup 201}TI SPECT, were used in both cases for distinguishing radiation necrosis from tumor recurrence. These methods proved to be complimentary. For Patient 1, FDG-PET showed more limitations compared to {sup 201}Tl SPECT. FDG-PET results, on the other hand, were consistent with the final diagnosis and the SPECT image was false positive for tumor recurrence in Patient 2. 26 refs., 9 figs.