Radionecrosis induced by stereotactic radiosurgery of brain metastases: results of surgery and outcome of disease.

Sterotactic radiosurgery (SRS) is an effective and commonly employed therapy for metastatic brain tumors. Among complication of this treatment, symptomatic focal cerebral radionecrosis (RN) occurs in 2-10 % of cases. The large diffusion of combined therapies as SRS followed by WBRT and/or CHT, has significantly amplified the number of patients who potentially might be affected by this pathology and neurosurgeons are increasingly called to treat suspected area of RN. Results of surgery of RN in patients with brain metastases are rarely reported in literature, a standardization of diagnostic work-up to correctly identify RN is still lacking and the timing and indications in favour of surgical therapy over medical treatments are not clear as well. In this retrospective study, we review current concept related to RN and analyze the outcome of surgical treatment in a series of 15 patients previously submitted to SRS for brain metastases and affected by suspected radionecrotic lesions. After surgery, all patients except one neurologically improved. No intra-operative complications occurred. Brain edema improved in all patients allowing a reduction or even suspension of corticosteroid therapy. Pure RN was histologically determined in 7 cases; RN and tumor recurrence in the other 8. Overall median survival was 19 months. An aggressive surgical attitude may be advisable in symptomatic patients with suspected cerebral RN, to have histologic confirmation of the lesion, to obtain a long-lasting relief from the mass effect and brain edema and to improve the overall quality of life, sparing a prolonged corticosteroid therapy.