Brain radionecrosis after radiation therapy for atypical meningioma: An unexpected treatment outcome. Case report

Introduction. Atypical Meningioma (AM) is at high risk of local failure. The role of radiation therapy (XRT) as an adjuvant to surgical resection is incompletely defined. The most deleterious consequence of brain-directed XRT is radiation necrosis. Brain radionecrosis (BRN) after AM has been rarely reported. The relevant literature is reviewed, highlighting its diagnostic challenges. Case Presentation. We report a 25-year-old male with a BRN after adjuvant XRT for AM, which has been misdiagnosed as a recurrent neoplastic lesion upon magnetic resonance spectroscopy (MRS) examination. Surgery and histopathological description were made and yielded a definitive diagnosis of BRN. The patient was treated by dexamethasone with concomitant hyperbaric oxygen therapy (HBO2). The patient showed a further progression of the disease. Therefore, he was elected to receive bevacizumab. However, the patient finally died for refractory brain edema. Conclusion. BRN is a relatively rare instance after XRT for AM. There is no single modality that can reliably distinguish BRN from tumour recurrence.  Therefore, reaching an early prompt treatment decision is challenging.