ESTRO 2024 - Abstract Book

S655

Clinical - Breast

ESTRO 2024

References:

[1] Wang S-L, Fang H, Song Y-W, Wang W-H, Hu C, Liu Y-P, et al. Hypofractionated versus conventional fractionated postmastectomy radiotherapy for patients with high-risk breast cancer: a randomised, non-inferiority, open-label, phase 3 trial. Lancet Oncol 2019;20:352 – 60

[2] Hypofractionated vs Standard Radiotherapy in Breast Cancer With an Indication for Regional Lymph Node Irradiation About Lymphedema Occurrence (HYPOG-01) ClinicalTrials.gov ID NCT03127995

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Digital Poster

deep inspiration breath-hold techniques for left-sided breast cancer

Luca Frassinelli 1 , Rachele Petrucci 1 , Simone Baroni 1 , Anna Sardo 2 , Cristina Pugliatti 2 , Nicola Padula 3 , Francesco Lucio 1 , Alessia Reali 1 1 Ospedale Michele e Pietro Ferrero ASL CN 2, SSD Radioterapia, Verduno, Italy. 2 Ospedale Michele e Pietro Ferrero ASL CN 2, SSD Fisica Sanitaria, Verduno, Italy. 3 Università degli studi di Torino, SSD Fisica Sanitaria, Torino, Italy

Purpose/Objective:

The purpose of this study is to evaluate the benefit of the Deep Inspiratory Breath-Hold (DIBH) technique performed with the Respiratory Gating for Scanners (RGSC; Varian Medical Systems, Palo Alto, CA, USA) system, as regards the left lung, heart and left anterior descending artery coronary (LADAC) sparing and to identify pre treatment anatomical parameters as possible predictors for the most appropriate technique choice.

Material/Methods:

Thirty-four patients with left-sided breast cancer (LSBC) after breast conservative surgery treated in our institution with 40.5 Gy in 15 fractions (or 48 Gy with simultaneous integrated boost) were enrolled. All patients underwent two sequential CT simulations in supine position: the first in free breathing (FB) and the second in DIBH, using the RGSC system. A combined tangential and volumetric fields has been used for treatment plans for both CT scans. The Dose-Volume Histograms were generated for both plans. The deep inspiration amplitude in DIBH and the average respiratory excursion in FB were recorded. The cardiac contact distances in axial (CCDax) and parasagittal (CCDps) plans and the lateral heart-to-chest distance (HCD) in the FB and DIBH techniques were measured. Paired t-test and correlation analysis were performed to compare anatomical and dosimetric variables and to get predictor parameters for cardiac, LADAC and left lungsparing.

Results: