P13.15 Multi-fraction stereotactic radiosurgery (MF-SRS) versus surgery plus MF-SRS for patients with large radioresistant brain metastases

Abstract

AbstractPurpose:Both surgery and radiosurgery (SRS) are frequently used in the initial management of patients with brain metastases. We have evaluated the local control and the radiation-induced brain necrosis in patients with large resistant brain metastases (>2 cm in size) who received multi-fraction stereotactic radiosurgery (MF-SRS) or surgery followed by MF-SRS.Patients and Methods:Patients with renal cell carcinoma and melanoma brain metastases > 2 cm in size treated with MF-SRS (3 x 9 Gy) or surgery + MF-SRS to resection cavity were analyzed. The primary end point of the study was the local control.Results:Between from March 2005 to June 2015, a total of 91 patients (MF-SRS, 46 pts; surgery + MF-SRS, 45 pts) were evaluated in this study. The median survival times were 13.2 months and 16.1 months in MF-SRS and surgery + MF-SRS groups, respectively (p = 0.03) and months. The 6-month and 12-month local control rates were 82% and 63% after MF-SRS and 91% ad 83% after surgery + MF-SRS (p = 0.01), respectively; the 1-year incidence of new distant brain metastases were 53% and 45%, respectively (p = 0.1). Nine patients undergoing surgery + MF-SRS and 4 subjected to MF-SRS experienced brain radionecrosis (p=0.1), as suggested by magnetic resonance imaging (MRI) and (F-DOPA) PET-CT imaging. According to RTOG Common Toxicity Criteria, neurological grade 3 toxicities due to brain radionecrosis was similar between groups (MF-SRS, 2 pts; surgery + MF-SRS, 4 pts). For both groups, the target volume and the volumes of normal brain receiving doses of 18–21 Gy were predictive of radionecrosis.Conclusions:For patients with large resistant brain metastases, surgery plus MF-SRS is an effective treatment modality associated with better local control as compared with MF-SRS alone. These results need to be confirmed in prospective randomized studies.