ESTRO 2025 - Abstract Book

S520

Clinical - Breast

ESTRO 2025

Material/Methods: We conducted a non-blinded, two-arm retrospective study. 44 patients indicated for adjuvant radiotherapy for left breast cancer following conservative surgery were analyzed; they were assigned in a 1:1 ratio to DIBH or free breathing during 2023 to date.

Results: 44 patients (22-DIBH arm, 22-Free Breathing). All were female. A mean age 55y (34-77). TABLE 1

Dose Distribution Analysis: (FIGURE 1): DIBH Mean Dose Heart: 90.95cGy; Free Breathing Mean Dose Heart: 164.63cGy (p<0.003). DIBH Maximum Dose Heart: 1382.54cGy; Free Breathing Maximum Dose Heart: 1918.45cGy (p<0.02). DIBH Mean Dose Left Lung: 370cGy; Free Breathing Mean Dose Left Lung: 394.95cGy (p=0.2). DIBH Maximum Dose Left Lung: 2671.59cGy; Free Breathing Maximum Dose Left Lung: 2619.95cGy (p<0.06).