Preoperative Single-Fraction Versus Fractionated Stereotactic Radiation Therapy: A Single-Institutional Analysis of 299 Resected Metastases.

Abstract

PurposeThe treatment standard for patients with large or symptomatic brain metastases and limited intracranial disease is surgical resection followed by postoperative stereotactic radiosurgery (SRS). Preoperative SRS may lead to a reduced incidence of radiation necrosis (RN), local failure (LF), and nodular meningeal disease (nMD). Fractionated treatments may reduce the incidence of LF and nMD. We hypothesize that preoperative fractionated stereotactic radiation therapy will reduce the incidence rate of RN, LD, and nMD compared to patients receiving preoperative SRS.Methods and materialsPatients who had surgical resection and preoperative radiation to at least one brain metastasis at a single institution were retrospectively analyzed. Outcomes were evaluated on a per-lesion basis. The primary outcome was a composite endpoint defined by (1) LF; (2) nMD; and/or (3) grade 2 or higher (symptomatic) RN.Results299 resected brain metastases from 260 patients were eligible for analysis. Two hundred thirty-five metastases received fractionated stereotactic radiation therapy (FSRT) and 64 received SRS. Thirty-eight patients had multiple metastases resected preoperatively. Overall, 4 (6.3%) SRS and 6 (2.6%) FSRT metastases experienced LF. Four (6.2%) SRS and 21 (9.1%) FSRT metastases experienced grade 2 or higher RN. Three (4.7%) SRS and 11 (4.7%) FSRT metastases were diagnosed with leptomeningeal disease. Additionally, 3 (4.6%) and 0 (0%) of SRS, and 8 (3.4%) and 4 (1.7%) of FSRT patients experienced classical or nodular meningeal disease, respectively. Eleven percent and 12% of SRS and FSRT metastases experienced the composite endpoint.ConclusionsIn our study, preoperative SRS and FSRT both appear to be safe and effective options to treat resectable brain metastases. It is important to prospectively compare preoperative SRS and FSRT in matched cohorts to assess any differences in treatment efficacy and toxicity.