ESTRO 2024 - Abstract Book

S551

Clinical - Breast

ESTRO 2024

A total of 670 breast cancer patients were enrolled in the study, with a median follow-up of 31 months, ranging from 22 to 45 months. The median age of the patients was 57 years. The majority of patients were diagnosed with early-stage disease (T1-2/N0-N1), and 81.6% of them underwent breast-conserving surgery. Of the 123 women who underwent mastectomy, 71 (57.7%) underwent immediate breast reconstruction, 53 (74.7%) with implants and 18 (25.3%) with autologous tissue. Radiation dermatitis emerged as the most common acute toxicity, with 2.9% of patients experiencing grade 3 reactions. Acute dermatitis grades 1, 2 and grade 3 for breast reconstruction and no breast reconstruction patients were 90.1%, 1.3% and 73.1%, 3.6%, respectively. Acute skin retraction occurred in 2 (0.3%) patients without breast reconstruction. Acute skin retraction was not observed in breast reconstruction patients. The occurrence of late toxicity was relatively low. There were no significant differences related to any grade of skin retraction (4.2% versus 3%; p=0.5), breast fibrosis (8.4% versus 7.2%; p=0.3) and hyperpigmentation (12.6% versus 15%; p=0.1) for breast reconstruction and no breast reconstruction patients, respectively. Any grade of capsular contracture was detected in 4 of 35 patients (11.4%) who underwent immediate breast reconstruction with implants.

Conclusion:

Moderately hypofractionated radiation therapy was well tolerated in both groups, with or without breast reconstruction. Breast-related complications are expected to be low and comparable between those groups.

Keywords: Moderately hypofractionated, breast reconstruction

1489

Proffered Paper

Impact of Cardiac Radiation Dose on Subclinical and Clinical Cardiotoxicity HER2+ Breast Cancer

Tae Hoon Lee 1 , Nalee Kim 1 , Eun Kyoung Kim 2 , Young-Hyuck Im 3 , Jin Seok Ahn 3 , Yeon Hee Park 3 , Won Kyung Cho 1 , Won Park 1 , Tae Gyu Kim 4 , Haeyoung Kim 1 1 Samsung Medical Center, Department of Radiation Oncology, Seoul, Korea, Republic of. 2 Samsung Medical Center, Division of Cardiology, Seoul, Korea, Republic of. 3 Samsung Medical Center, Division of Hematology-Oncology, Seoul, Korea, Republic of. 4 Samsung Changwon Hospital, Department of Radiation Oncology, Changwon, Korea, Republic of

Purpose/Objective:

To assess the cardiac event rate and the associations between cardiac radiation dose, events, and myocardial dysfunction in HER2+ breast cancer patients receiving trastuzumab and postoperative radiation therapy (RT).

Material/Methods: