e13589 Background: We report our experience with volumetric modulated arc therapy (VMAT-IGRT) use to plan and deliver whole brain radiotherapy whit a simultaneous integrated boost in patients with brain metastases, using hippocampal sparing. Methods: In this retrospective study 57 patients with brain metastases were treated with radiotherapy VMAT-IGRT were administered in 12 daily fractions of 2.7Gy for a total of 32.4Gy (EBD 40Gy) to whole-brain and simultaneous integrated boost to brain metastases, multiple targets, in 12 fractions to 3.4Gy for a total dose of 40.8Gy (EBD 60Gy). The primary endpoint was intracranial progression-free survival (PFS) and secondary endpoints were preserves neurocognitive function and overall survival (OS). Survival rates were determined by Kaplan-Meier method. Differences between survival curves were analyzed by the log-rank test. Results: From January 2015 to December 2018, 57 patients were enrolled. The median follow-up time was 7 months. PFS6, PFS12 and PFS18 were 91.3%, 70.8% and 70.8% respectively. mOS, OS6, OS12 and OS18 were 10 months (95% IC 4.2-15.7 months), 67.2%, 48.6% and 35.3% respectively. Response rates were as follows: 29RC (50.9%), 21RP (36.8%), 7SD (12.3%) and 0PD (0%). Long progression-free survival patients: PFS > 12, 15 and 18 months for initial diagnosis 70%, 70% and 70% respectively. Conclusions: Whole-brain radiotherapy with simultaneous integrated boost to brain-metastases: VMAT-IGRT is safe and promising and possibly produces survival and tolerance benefits. Sparing the hippocampus during cranial irradiation poses important technical challenges with respect to contouring and treatment planning.
EP-1130: Hair-sparing whole brain radiotherapy with simultaneous integrated boost using high density bolus
