ESTRO 2023 - Abstract Book

S762

Monday 15 May 2023

ESTRO 2023

and Trastuzumab were used in 369 pts (73%), 97 pts (19%) and 21 pts (4%) respectively.

With a MFU of 61 months [55–72], 5-y 3rdIBTE-FS, RRFS, MDFS, DFS, SS and OS were 96% [94–98], 98% [97–100], 93% [90– 96], 89% [86–93], 95% [92–97] and 91% [88–94] respectively. In univariate analysis, tumor (>20 mm), [APBI/Mol] class. and [APBI/Mol/TIS1S2] class. were prognostic factors for all the oncological items while TIS1S2 (<36 m) was prognostic factor for RRFS, MDFS, SS and OS. In multivariate analysis, [APBI/Mol/TIS1S2] class. was the unique independent prognostic factor for all the oncological items but SS (trend) and OS (Fig. 2) . 404 late complications were observed in 298 pts (59%). Cutaneous and sub-cutaneous fibrosis were reported in 67.9%. The rate of G ≥ 3 late toxicity was 12.1%. Cosmetic outcome was excellent and good in 36.8% and 30.3% respectively.

Figure 2:

Conclusion In this updated analysis of its 2ndCT database, the GEC-ESTRO BCWG confirmed the excellent oncological results obtained after 2nd lumpectomy + MIB based APBrI for 2ndBTE. Furthermore, we provided new prognostic factors for discussing 2ndCT. [APBI/Mol/TIS1S2] class. appears to be an important tool for leading the making decision process. OC-0917 ESTRO/EORTC consensus definition of re-irradiation paving the way for the prospective ReCare cohort N. Andratschke 1 , J. Willmann 2 , A. Appelt 3 , N. Alyamani 4 , P. Balermpas 5 , B. Baumert 6 , C. Hurkmans 7 , M. Høyer 8 , J. Langendijk 9 , O. Kaidar-Person 10 , Y. van der Linden 11 , I. Meattini 12 , M. Niyazi 13 , N. Reynaert 14 , D. de Ruysscher 15 , S. Tanadini Lang 5 , P. Hoskin 16 , P. Poortmans 17 , C. Nieder 18 1 University Hospital of Zurich, Dept. of Radiation Oncology, Zurich, Switzerland; 2 Paul Scherrer Institute , Center for Proton Therapy, Villigen, Switzerland; 3 University of Leeds, Leeds Institute of Medical Research at St. James's, Leeds, United Kingdom; 4 European Organisation for Research and Treatment of Cancer, Headquarters, Brussels, Belgium; 5 University Hospital of Zurich, University of Zurich, Dept. of Radiation Oncology, Zurich, Switzerland; 6 Cantonal Hospital of Graubünden, Institute of Radiation-Oncology, Chur, Switzerland; 7 Catharina Hospital Eindhoven, Dept. of Radiation Oncology, Eindhoven, The Netherlands; 8 Aarhus University Hospital, Danish Centre for Particle Therapy, Aarhus, Denmark; 9 University Medical Center Groningen, Dept. of Radiation Oncology, Groningen, The Netherlands; 10 Sheba Medical Center, Breast Cancer Radiation Therapy Unit, Ramat Gan, Israel; 11 University Medical Centre Leiden , Dept. of Radiation Oncology, Leiden, The Netherlands; 12 Azienda Ospedaliero Universitaria Careggi, Radiation Oncology Unit, Oncology Department, Florence, Italy; 13 University Hospital, LMU Munich, Dept. of Radiation Oncology, Munich, Germany; 14 Institut Jules Bordet, Dept. of Medical Physics, Brussels, Belgium; 15 Maastricht University Medical Centre, Dept. of Radiation Oncology Maastro, Maastricht, The Netherlands; 16 University of Manchester, Mount Vernon Cancer Centre and Division of Cancer Sciences, Manchester, United Kingdom; 17 Iridium Netwerk, University of Antwerp, Faculty of Medicine and Health Sciences, Department of Radiation Oncology , Wilrijk-Antwerp, Belgium; 18 Nordland Hospital Trust, Department of Oncology and Palliative Medicine, Bodø, Norway

Purpose or Objective