Copenhagen, Denmark

ESTRO 2022

Session Item

Poster (digital)
Acute toxicity of hypofractionated locoregional radiotherapy in advanced breast cancer
Roberta Tummineri, Italy


Acute toxicity of hypofractionated locoregional radiotherapy in advanced breast cancer

Roberta Tummineri1, Andrei Fodor1, Flavia Zerbetto1, Marcella Pasetti1, Chiara Lucrezia Deantoni1, Ariadna Sanchez Galvan2, Roberta Castriconi3, Paola Mangili3, Antonella Del Vecchio3, Nadia Gisella Di Muzio4

1IRCCS San Raffaele Scientific Institute, Radiation Oncology, Milano, Italy; 2Milano-Bicocca University, Radiation Oncology, Milano, Italy; 3IRCCS San Raffaele Scientific Institute, Medical Physics, Milano, Italy; 4IRCCS San Raffaele Scientific Institute - Università Vita-Salute, Radiation Oncology, Milano, Italy

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Purpose or Objective

Hypofractionated whole breast radiotherapy is considered the standard after conservative surgery for breast cancer (BCa), but the interest in hypofractionation is growing even for locoregional treatments, involving not only breast/chest wall, but also lymph nodal (LN) areas. We report acute toxicity in patients with advanced BCa treated with hypofractionated radiotherapy (HRT) to breast/chest wall and regional LN in our Institute.

Material and Methods

From 03/2018 to 05/2021 132 pts with diagnosis of advanced BCa pts (98% female, 2% male) underwent locoregional HRT after conservative surgery (58%) or mastectomy (40.5%), and 3 pts received radical RT (1.5%). Two pts had bilateral BCa (134 irradiated breasts). Median age was 52 (26-86) years. Molecular subtypes were: Luminal A 29%, Luminal B Her2- 28.5%, Luminal B Her+ 19%, HR negative Her2+ 13% and Triple negative 10.5%. Neoadjuvant chemotherapy was prescribed in 55% of pts, adjuvant in 55%, and concomitant in 11%. Adjuvant hormonal therapy was prescribed in 76% of pts (IA or TMX -/+ LH-RH analogue). Thirty-three % of pts underwent HER2-targeted therapy. Treatments were delivered with 3DCRT (11%), VMAT (30%) or Tomotherapy (59%, TomoDirect or TomoHelical), to a total dose of 40.05 Gy in 15 fractions, delivered in 3 weeks, to breast/chest wall and regional LNs. A simultaneous integrated boost (SIB) up to 48 Gy to the tumor bed was delivered for pts with high-risk local relapse. The target was: whole breast in 60% (46% right, 54% left), chest wall in 40% (40% right, 60% left, 33% without and 67% with post-mastectomy reconstruction), supraclavicular LN in 100%, axillary LN in 34.4%, and internal mammary chain in 13.5% of cases, respectively. A SIB to the tumor bed was delivered in 34.5% of pts. Acute toxicity was registered according to CTCAE v 4.0.


Acute toxicity is summarized in table 1. No patient experienced ≥G3 acute toxicity. No significant differences in toxicity were found between the different RT techniques. G2 skin toxicity was experienced in 13% of pts with SIB and 8% without SIB. Significant increase of G1-G2 skin toxicity and dysphagia were found in pts treated on chest wall with post-mastectomy reconstruction (as summarized in table 2).


Locoregional HRT is feasible with low acute toxicity without significant differences in toxicity between the different RT techniques. Longer follow-up is needed to evaluate late toxicity and local control in the different subgroups of patients.