Brain radiation necrosis (BRN) is a side effect of radiotherapy (RT), affecting mainly the white matter and can appear from a few weeks to several years after RT. It's incidence of 3-9% is increasing as survival increases. Histopathology (HP) shows avascular damage, demyelination and direct necrosis.

Brain radiation radionecrosis and the tumor progression are difficult to differentiate as both entities are presented with similar radiological and clinical characteristics, such as neurological deficit, brain edema and contrast enhancement.

Recurrent aggressive BRN is infrequent. Big recurrences in a few months is possible but uncommon. BRN still remains an important diagnostic challenge to determine the best treatment option. This entity can present with important neurological deficits, big mass lesions and edema and may require multiple surgeries to control its growth and improve the clinical status. The 5-ALA intraoperatively, could help to assess the presence of tumor intraoperatively. In some cases, hyperbaric oxygen and anti-VEGF (vascular endotelial grow factor) therapy may be useful as treatments when surgery cannot be done or it's been refused.

Radionecrosis may behave more aggressively than high-grade glioma itself. Sometimes it is necessary to perform several interventions and therefore increase the morbidity and mortality in these patients.