ESTRO 2023 - Abstract Book

S2107

Digital Posters

ESTRO 2023

coverage parameters for target volumes (PTVbreast; CTVboost+3mm= PTVboost) and OAR constrains heart Dmean; lung Dmean; ipsilateral lung V20 and contralateral breast V5 and Dmax. Survival curves were estimate by Kaplan-Meier survival analysis (IBM.SPSS.Statistics v21). Results Results: Thee-hundred and ninety PTS between March 2013 and December 2016 had HFSIB. Thirty-nine PTS were lost to follow-up for clinical and survival analysis. Median PTS age was 54 years old. 359 PTS (92%) were treated with IMRT and 31 (8%) with VMAT. 210 PTS with left breast and 180 PTS right breast. Coverage parameters guaranteed in all PTS were 95% of the prescribed dose in at least V95% (PTVbreast and PTVboost). The OAR constrains are described in table.1. PTS tumour enrolled were CDIS n=35 and tumour biology (Luminal A n=165; Luminal B n=92; HER2+ n=34 and TN n=25). The median follow-up was 6.9 years. Five-year estimated local recurrence-free survival was 98,6% (95%CI: 77,86-99,74; P=0,762); loco- regional recurrence free-survival 99,1% (95%CI: 79,9-112,0; P=0,393) non-statistically significant for tumour biology. The distant recurrence free-survival was 78,3% (95%CI: 70,1-86,5; P=0,038).