Radiation necrosis from recurrence Of brain malignancy can be best differentiated by

Radiation necrosis from recurrence Of brain malignancy can be best differentiated by PET Scan. Radiation necrosis is a phenomenon seen in high grade gliomas after radiotherapy and may mimic tumour recurrence, thus challenging in clinician's decision for treatment of the same. Conventional MRI sequences are not able to differentiate between these two entities. On PET scan, radiation necrosis may show (not always) decreased uptake in comparison to tumour recurrence. Thus, ideally the best way to differentiate between two entities is brain biopsy.