ESTRO 2022 - Abstract Book

S1013

Abstract book

ESTRO 2022

Conclusion This works shows the feasibility of performing thermotherapy treatment planning in conjunction with preoperative radiotherapy. Additionally, we have generated the largest repository of patient derived breast models. This repository provides a unique platform to advance the field of intact breast thermotherapy by facilitating an objective comparison of the heating quality for different thermotherapy devices using the same set of patient derived models.

PO-1193 Outcomes following hypofractionation to nodal region after surgery in locally advanced breast cancer

R.R. Colciago 1 , F. Tramacere 2 , S. Arcangeli 1 , R. Lucchini 1 , F. Pati 3 , M. Portaluri 3

1 School of Medicine and Surgery – University of Milan Bicocca, Department of Radiation Oncology, Milano, Italy; 2 ASL A. Perrino, Department of Radiation Oncology , Brindisi, Italy; 3 ASL A. Perrino, Department of Radiation Oncology, Brindisi, Italy Purpose or Objective In daily clinical practice, there are concerns about the potential toxicity of hypofractionated (HF) post-mastectomy radiation therapy (PMRT) and regional nodal irradiation (RNI). In this retrospective study, we aimed to analyze the impact on outcomes and toxicity of a 3-week HF schemes after axillary dissection and breast surgery (quadrantectomy or mastectomy), to assess its safety and efficacy in patients with locally advanced breast cancer (BC). Materials and Methods Eligible patients were women with stage IIA – IIIC pathologically confirmed invasive BC who underwent axillary dissection and breast surgery (conservative or mastectomy) including patients who underwent breast reconstruction or received neoadjuvant or adjuvant systemic therapy. Two different hypofractionation schedules were allowed: 40.05 Gy in 15 fractions over 3 weeks and 42.56 Gy in 16 fractions daily, both with an optional sequential boost of 10 Gy in 4 fractions. RT was delivered using 3D planning techniques. Using Kaplan-Meier survival procedure, loco-regional recurrence (LRR), distant metastases free survival (DMFS) overall survival (OS) and acute and late toxicities were analyzed.