ESTRO 2022 - Abstract Book

S1038

Abstract book

ESTRO 2022

dissection (96.5%). Non-pCR was observed in 76 pts (67.3%). Radiotherapy delivered a median dose of 50 Gy to the breasts or the chest wall in 25 fractions; Berg’s level I, II-III, IV and internal mammary chains were included in 21.2%, 88.5%, 89.4% and 85% of all patients respectively. While the majority were treated with 3D technique, 11 pts were treated with rotational IMRT (VMAT or helical tomotherapy). With a median follow-up of 54 months, 5-year OS, DFS and LRRFS were 78% [CI: 70.1-86.8%], 68.1% [59.6%-77.7%] and 85.2% [78.4%-92.7%] respectively. In multivariate analysis, non-pCR was an adverse prognosis factor for OS, DFS and LRRFS; pre- operative RT was an adverse prognosis factor for OS and DFS; TNBC and N+ disease were adverse prognosis factors for OS. Radiation-related adverse events were limited to acute skin toxicity (22% of grade 2 and 2% of grade 3 dermatitis); no late radiation-induced toxicity was reported.

Table 1: patient characteristics.

Table 2: Treatment characteristics.