Impact of radiation dose on complications among women with breast cancer who underwent breast reconstruction and post-mastectomy radiotherapy: A multi-institutional validation study. (April 2021)

• Record Type: Journal Article
• Authors: Chung, Seung Yeun; Chang, Jee Suk; Shin, Kyung Hwan; Kim, Jin Ho; Park, Won; Kim, Haeyoung; Kim, Kyubo; Lee, Ik Jae; Yoon, Won Sup; Cha, Jihye; Lee, Kyu-Chan; Kim, Jin Hee; Choi, Jin Hwa; Ahn, Sung-Ja; Ha, Boram; Lee, Sun Young; Lee, Dong Soo; Lee, Jeongshim; Shin, Sei One; Lee, Sea-Won; Choi, Jinhyun; Kim, Mi Young; Kim, Yeon Joo; Im, Jung Ho; Suh, Chang-Ok; Kim, Yong Bae
• Is Part Of: Breast. Volume 56(2021)
• Page Start: 7
• Page End: 13
• Publication Date: 2021-04
• Subjects: Breast cancer -- Breast reconstruction -- Major complication -- Radiation therapy; CI confidence interval -- EQD2 equivalent dose in 2 Gy fractions -- HER2 human epidermal growth factor receptor 2 -- MROC Mastectomy Reconstruction Outcomes Consortium -- OD odds ratio -- PMRT post-mastectomy radiotherapy -- RT Radiotherapy; Breast -- Diseases -- Periodicals; Breast -- Tumors -- Periodicals; Breast -- Periodicals; Electronic journals; Periodicals; 616
• DOI: 10.1016/j.breast.2021.01.003
• Languages: English
• ISSNs: 0960-9776

Abstract

Abstract: Purpose: Emerging data suggest that higher radiation doses in post-mastectomy radiotherapy may be associated with an increased risk of reconstruction complications. This study aimed to validate previous findings regarding the impact of radiation dose on complications among women with breast cancer using a multi-center dataset. Methods: Fifteen institutions participated, and women with breast cancer who received radiotherapy after either autologous or prosthetic breast reconstruction were included. The primary endpoint was major post-radiation therapy complications requiring re-operation for explantation, flap failure, or bleeding control. Results: In total, 314 patients were included. Radiotherapy was performed using both conventional fractionation and hypofractionation in various schedules. The range of the radiation therapy dose in Equivalent Dose in 2 Gy fractions (EQD2; α/β = 3.5) varied from 43.4 to 71.0 Gy (median dose: 48.6 Gy). Boost radiation therapy was administered to 49 patients. Major post-radiation therapy complications were observed in 24 (7.6%) patients. In multivariate analysis, an increasing EQD2 per Gy (odds ratio [OR]: 1.58, 95% confidence interval [CI]: 1.26–1.98; p < 0.001), current smoking status (OR: 25.48, 95% CI: 1.56–415.65; p = 0.023), and prosthetic breast reconstruction (OR: 9.28, 95% CI: 1.84–46.70; p = 0.007) were independently associated with an increased risk of major complications. Conclusion: A dose-response relationship between radiation dose and the risk of complications was validated in this multi-center dataset. In this context, we hypothesize that the use of hypofractionated radiotherapy (40 Gy in 15 fractions) may improve breast reconstruction outcomes. Our multi-center prospective observational study (NCT03523078) is underway to further validate this hypothesis. Highlights: Radiation dose is associated with the risk of breast reconstruction complications. We conducted a retrospective multi-center observational study of 314 women in Korea. Complication-related risk factors were identified using multivariate analysis. Use of hypofractionated radiation therapy may improve breast reconstruction outcomes. A prospective multi-center study is under way to further validate our findings.