Salvage stereotactic radiosurgery with adjuvant use of bevacizumab for heavily treated recurrent brain metastases: a preliminary report

It is not uncommon for brain metastasis (BM) treated with stereotactic radiosurgery (SRS) to demonstrate radiographic enlargement, with the patient developing neurological deficits attributable to a lesion at the site of SRS. The management of both local recurrence and radiation-induced necrosis (RN) poses a significant therapeutic dilemma, if surgical resection is not feasible, and effective therapies have yet to be established. This preliminary study introduces our initial experience with salvage SRS using adjuvant bevacizumab for this refractory entity. We retrospectively reviewed five patients who had received salvage SRS using adjuvant bevacizumab for recurrent BM complicated by RN. The diagnosis was based on clinical features, serial imaging studies and/or histopathological findings. Patients underwent salvage SRS followed by the first cycle of bevacizumab (7.5-10 mg/kg intravenous). Bevacizumab was repeated every 3-4 weeks until tumor progression or significant toxic events. The number of bevacizumab doses ranged from 2 to 16 (median 4). Follow-up MR imaging demonstrated a clear radiographic response in all lesions. Neurological symptoms improved in three patients and stabilized in two. In two patients, bevacizumab treatment was discontinued due to anemia and gastrointestinal bleeding, respectively. At the time of data analysis, four patients had died and the other was still alive. The causes of death were neurological decline and systemic disease progression in two patients each. Salvage SRS with adjuvant bevacizumab use appeared to provide an adequate radiographic response as well as neurological palliation for selected patients with heavily treated recurrent BM complicated by RN.