ESTRO 2024 - Abstract Book

S166

Brachytherapy - Breast

ESTRO 2024

Univariate log-rank tests for TN, EIC, young age, surgical margins and tumor size and Cox regression analysis showed no statistical significance.

Early skin toxicity was examined through the occurrences of radiodermatitis (29.9% Grade 1; 5.1% Grade 2) and erythroderma (22.6% Grade 1; 1.5% Grade 2), while late skin toxicity was examined through events of skin hyperpigmentation (11.7% Grade 1), skin hypopigmentation (2.2% Grade 1), telangiectasia (2.9% Grade 1), and skin atrophy (0.0%).

Late soft tissue toxicity was measured through the occurrences of infections (1.5%), seroma infections (0.0%), indurations (17.5%), lymphedema (9.5%), and fat atrophy (1.5%).

No patient experienced soft tissue toxicity Grade ≥3. Regarding both early and late skin toxicity, the results showed that most commonly occurred grade was Grade 0 (89.1%), with around 10% occurrences of Grade 1 (9.9%) and Grade 2 (1%). Over 70% of early skin toxicity was Grade 0, while the same grade constituted over 95% of late toxicity cases. No patient experienced skin toxicity Grade 3, 4, or 5.

16.1% patients suffered from Grade 1 chronical pain. Grade 2 (0.7%) chronical pain was less prevalent.

Conclusion:

Multicatheter BT boost is a safe treatment approach with a low side effect profile that resulted in an excellent LC in this high-risk cohort of breast cancer patients. Prospective studies with larger cohorts are necessary to validate the efficacy of BT boost.

Keywords: multicatheter, boost, OAR-sparing

References:

1. Bartelink H, Maingon P, Poortmans P, et al. Whole-breast irradiation with or without a boost for patients treated with breast-conserving surgery for early breast cancer: 20-year follow-up of a randomized phase 3 trial. Lancet Oncol 2015;16:47-56.