Radiation Oncology (Apr 2020)
Brain metastases treated with hypofractionated stereotactic radiotherapy: 8 years experience after Cyberknife installation
Abstract
Abstract Background Hypofractionated stereotactic radiotherapy (HFSRT) is indicated for large brain metastases (BM) or proximity to critical organs (brainstem, chiasm, optic nerves, hippocampus). The primary aim of this study was to assess factors influencing BM local control after HFSRT. Then the effect of surgery plus HFSRT was compared with exclusive HFSRT on oncologic outcomes, including overall survival. Materials and methods Retrospective study conducted in Léon Bérard Cancer Center, included patients over 18 years-old with BM, secondary to a tumor proven by histology and treated by HFSRT alone or after surgery. Three different dose-fractionation schedules were compared: 27 Gy (3 × 9 Gy), 30 Gy (5 × 6 Gy) and 35 Gy (5 × 7 Gy), prescribed on isodose 80%. Primary endpoint were local control (LC). Secondary endpoints were overall survival (OS) and radionecrosis (RN) rate. Results A total of 389 patients and 400 BM with regular MRI follow-up were analyzed. There was no statistical difference between the different dose-fractionations. On multivariate analysis, surgery (p = 0.049) and size ( 2.5 cm) with a poorer prognosis. Multidisciplinary committees and prospective studies are necessary to validate these observations.
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