ESTRO 2025 - Abstract Book

S615

Clinical - Breast

ESTRO 2025

groups when comparing the incidence and severity of post irradiation toxicities in relation to mutational status, genetic mutation penetrance grade or fractionation regimen.

Conclusion: Our study highlights that breast cancer patients with high-penetrance genetic mutations have higher relapse rates compared to those with moderate/low-penetrance genetic mutations or with no mutations. These findings underscore the need for personalized treatment strategies that consider genetic profiles to improve outcomes in this high-risk population.

Keywords: genetic mutations, relapse rate, toxicities

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Digital Poster Deep Inspiration Breath Hold and Ultrahypofractionated Breast Radiation Therapy: a Smart and Safe Solution for Every Age. Elisabetta Bonzano 1 , Jessica Saddi 1 , Andrea Lancia 1 , Salvatore La Mattina 1 , David Alberto Santos 2 , Valentina Bartolomeo 3 , Luigi Squillace 1 , Sara Colombo 1 , Laura Mantovani 4 , Anna Enrica Francia 4 , Monica Cavallari 4 , Gaetano Urso 4 , Paolo Pedrazzoli 5,6 1 Radiation Oncology, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy. 2 Radiation Oncology, National Institute of Health of El Salvador, San Salvador, El Salvador. 3 Departement of Clinical Surgical Diagnsotic and Pediatric Sciences, University of Pavia, Pavia, Italy. 4 Departement of Medical Physics, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy. 5 Medical Oncology, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy. 6 Departement of Internal Medicine and Therapeutics, University of Pavia, Pavia, Italy