ESTRO 2025 - Abstract Book

S495

Clinical - Breast

ESTRO 2025

65, evaluating the acceptance, feasibility, and benefits of DIBH compared to free breathing (FB), the use of DIBH in the increasing number of patients over 65 years remains largely underexplored (2, 3).

Material/Methods: The current study consists of two parts: 1. A prospective pseudonymized survey study using a one-time paper-based questionnaire among female breast cancer patients over 65 years of age focusing on their attitude and interest in DIBH. 2. A matched pair anlaysis of patients included in the prospective GATTUM and B-REST trials compared patients over 65 years (n=30) to patients under 65 years (n=30) regarding breathing amplitude, stability and dose reduction in the OARs (lung, heart) due to DIBH. Data were analyzed descriptively, and dosimetric endpoints were evaluated using wilcoxon- and t-test. Results: 1. In the prospective survey study, 75 % of 100 female breast cancer patients over 65 years of age expressed interest in RT with DIBH, and 98 % stated that age should not be a criterion for offering DIBH. 2. The analyses of the match-paired age groups treated in the prospective trial revealed no significant differences in breathing amplitude, delta of breath holding, or breath hold duration between patients over (n=30) and under (n=30) 65 years of age. Likewise, the improvements of DIBH compared to FB in terms of total lung volume, Heart Dmean dose, LAD Dmean dose, and left lung V18 were similar across both age groups. Conclusion: This study shows that female breast cancer patients over 65 years are both willing and capable of performing RT in DIBH. This result suggests the wide applicability of DIBH in breast cancer across age groups, and indicates that age should not be a decision criterion for DIBH application in patients with left-sided breast cancer. References: 1. Hayden AJ, Rains M, Tiver K. Deep inspiration breath hold technique reduces heart dose from radiotherapy for left-sided breast cancer. J Med Imaging Radiat Oncol. 2012;56(4):464-72. 2. Nissen HD, Appelt AL. Improved heart, lung and target dose with deep inspiration breath hold in a large clinical series of breast cancer patients. Radiother Oncol. 2013;106(1):28-32. 3. Ledsom D, Reilly AJ, Probst H. Assessment of deep inspiration breath hold (DIBH) amplitude and reduction in cardiac dose in left breast cancer patients. Radiography (Lond). 2018;24(2):98-103. Keywords: DIBH in elderly, RT in breast cancer Digital Poster Single-fraction stereotactic partial breast irradiation (S-PBI) using the Gammapod system: results of a phase II study Giuseppe Facondo 1 , Agnese Prisco 1 , Chiara Reverberi 1 , Tino Ceschia 1 , Marika Guarnieri 2 , Eugenia Moretti 2 , Paolo Scalchi 2 , Carla Cedolini 3 , Marco Trovo 1 1 Radiation Oncology, ASUFC "Santa Maria della Misericordia", Udine, Italy. 2 Medical Physics Unit,, ASUFC "Santa Maria della Misericordia", Udine, Italy. 3 Breast Surgery, ASUFC "Santa Maria della Misericordia", Udine, Italy Purpose/Objective: To investigate the safety of single fraction stereotactic Partial Breast Irradiation (S-PBI) after breast conserving surgery using the GammaPod system, a novel technology designed to deliver a highly focused dose to the breast under stereotactic localization. 1825