by Seung Yeun Chung, Jee Suk Chang, Kyung Hwan Shin, Jin Ho
Kim, Won Park, Haeyoung Kim, Kyubo Kim, Ik Jae Lee, Won Sup Yoon, Jihye Cha,
Kyu-Chan Lee, Jin Hee Kim, Jin Hwa Choi, Sung-Ja Ahn, Boram Ha, Sun Young Lee,
Dong Soo Lee, Jeongshim Lee, Sei One Shin, Sea-Won Lee, Jinhyun Choi, Mi Young
Kim, Yeon Joo Kim, Jung Ho Im, Chang-Ok Suh, Yong Bae Kim
The Breast : VOLUME 56, P7-13, APRIL 01, 2021
(published online: January 20, 2021)
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.
