ESTRO 2024 - Abstract Book

S1539

Clinical - Lower GI

ESTRO 2024

2. Morton, M., et al (2018). Squamous cell carcinoma of the anal canal. Current problems in cancer, 42(5), 486– 492. https://doi.org/10.1016/j.currproblcancer.2018.11.001

3. Benson, A. B., Venook, A. P., et al (2023). Anal Carcinoma, Version 2.2023, NCCN Clinical Practice Guidelines in Oncology. Journal of the National Comprehensive Cancer Network : JNCCN, 21(6), 653–677. https://doi.org/10.6004/jnccn.2023.0030

4. Niehoff, P., & Kovács, G. (2014). HDR brachytherapy for anal cancer. Journal of gastrointestinal oncology, 5(3), 218–222. https://doi.org/10.3978/j.issn.2078-6891.2014.027

2200

Mini-Oral

Neoadjuvant radiochemotherapy in locally advanced rectal cancer with or without radiation dose boost

Luca Nicosia 1 , Marco Lorenzo Bonù 2 , Ilaria Angelicone 3 , Micol Zannetti 4 , Rita Marina Niespolo 5 , Giuditta Chiloiro 6 , Francesca De Felice 7 , Angela Romano 6 , Giampaolo Montesi 8 , Filippo De Renzi 9 , Pierfrancesco Franco 4 , Stefano Arcangeli 5 , Stefano Maria Magrini 10 , Filippo Alongi 1 , Mattia Falchetto Osti 3 1 IRCCS Sacro Cuore Don Calabria Hospital, Cancer Care Center, Advanced Radiation Oncology Department,, Negrar, Italy. 2 ASST Spedali Civili di Brescia, Radiation Oncology Department, Brescia, Italy. 3 "Sapienza" University, Sant'Andrea Hospital, Department of Radiation Oncology, Rome, Italy. 4 Azienda Ospedaliera Universitaria (AOU)'Maggiore della Carità, Radiation Oncology Department, Novara, Italy. 5 Fondazione IRCCS San Gerardo dei Tintori, Radiation Oncology, Monza, Italy. 6 Dipartimento Diagnostica per Immagini, Radioterapia Oncologica ed Ematologia, Fondazione Policlinico Universitario A. Gemelli IRCCS, UOC di Radioterapia Oncologica, Rome, Italy. 7 Department of Radiological, Policlinico Umberto I,, Radiation Oncology, Rome, Italy. 8 ULSS5, Radiotherapy Unit, Rovigo, Italy. 9 San Martino Hospita, Radiotherapy Unit, Belluno, Italy. 10 ASST Spedali Civili di Brescia, 2. Radiation Oncology Department, Brescia, Italy

Purpose/Objective:

Preoperative radiochemotherapy (RCHT) is the standard treatment for locally advanced rectal cancer (LARC). The evidence that pCR is a favorable independent prognostic factor for overall survival (OS) propted to investigate the role of RCHT intensification of. Other than intensifying systemic treatments, it is possible to enhance preoperative treatments by escalating radiation dose. However, currently there are no robust data directly comparing different radiotherapy (RT) dose levels in terms of downstaging and pCR. The present multicenter retrospective study aims to compare different levels of intensification of the RT dose in LARC patients.

Material/Methods:

The present multicenter large retrospective study involves 11 Centers. The primary objective is to evaluate whether the increase of RT dose is associated with an increase in the rate of pCR. The secondary objectives are to evaluate the relation between treatment dose and interval to surgery, and compare downstaging, acute and late RT-related toxicity, perioperative toxicity, local and distant recurrence, and OS between the 2 regimens.