Differentiation of radiation necrosis from glioblastoma recurrence after radiotherapy

The standard treatment of glioblastoma, the most common type of primary-brain-tumor, involves radiotherapy with concomitant temozolomide chemotherapy. A patient with glioblastoma, post radiotherapy developed magnatic resonance imaging (MRI) changes consistent with either radiation-induced tumor necrosis or tumor recurrence. Perfusion MRI was suggestive of radiation necrosis, but magnetic resonance spectroscopy and 99mTc-Tetrofosmin single photon emission computed tomography was indicative of tumor recurrence. Positron emission tomography scan was not available. Tumor recurrence was documented by biopsy. Several advanced imaging methods are available to differentiate tumor recurrence from radiation necrosis in glioblastoma patients. However, in inconclusive cases, brain biopsy should be performed for definite diagnosis