ESTRO 2024 - Abstract Book

S563

Clinical - Breast

ESTRO 2024

Material/Methods:

30 women with an average age of 51 years (34-60) have been treated with DIBH (Figure 1). Two supine CT scans were performed: one in FB for initial treatment positioning and another in DIBH. Moderate hypofractionation (40.05 Gy: 15*267 cGy/session) was prescribed in all patients. When indicated, an integrated boost was performed (total dose 45-48 Gy). All patients were planned twice with Monaco v. 5.10.02. The mean doses in the heart and ipsilateral lung, Dmax and V10 of the coronary arteries were compared between plans. The Student's T test for dependent samples was performed and the p value was calculated.

Results:

Dosimetric differences between the FB and DIBH techniques are shown in Figure 2. All dosimetric indicators were significantly reduced (p<0.05) with the DIBH technique. The mean heart dose and the maximum coronary dose decreased by almost 50% while the mean ipsilateral lung dose decreased by almost 15%. The V10 of the coronary arteries was reduced by up to 84% on average.

Conclusion: