We assessed the clinical benefit of combining volumetric-modulated arc therapy (VMAT) and hypofractionated radiotherapy (HF-RT) considering the incidence of radiation-related toxicities. After a retrospective review for breast cancer patients treated with adjuvant RT between 2005 and 2017, a total of 4209 patients treated with three-dimensional conventional fractionation (CF-3D, 50.4 Gy/28 fractions) and 1540 patients treated with HF-RT (768 received HF-3D; 772, HF-VMAT; 40 Gy/15 fractions) were included. A total of 2229 patients (38.8%) received regional node irradiation (RNI): 1642 (39.0%), 167 (21.7%) and 420 (54.4%) received RNI via CF-3D, HF-3D and HF-VMAT, respectively. Acute/subacute and late toxicities were evaluated. Propensity scores were calculated via logistic regression. Grade 2+ acute/subacute toxicities was the highest in CF-3D group (15.0%, 2.6% and 1.6% in CF-3D, HF-3D and HF-VMAT, respectively; P <.001). HF-VMAT reduced Grade 2+ acute/subacute toxicities significantly compared to CF-3D (odds ratio [OR] 0.11, P <.001) and HF-3D (OR 0.45, P =.010). The 3-year cumulative rate of late toxicities was 18.0% (20.1%, 10.9% and 13.4% in CF-3D, HF-3D and HF-VMAT, respectively; P <.001). On sensitivity analysis, the benefit of HF-VMAT was high in the RNI group. Acute and late toxicities were fewer after HF-VMAT than after HF-3D or CF-3D, especially in women who underwent RNI.
Bibliographical noteFunding Information:
The results were presented at the 62nd Annual Meeting of the American Society for Radiation Oncology, October 2020. This study was supported by the Research Grant of the Korean Foundation for Cancer Research (Grant number: 2017-B-3). The funders had no role in the design and conduct of the study; collection, management, analysis and interpretation of the data; preparation, review or approval of the manuscript; and decision to submit the manuscript for publication.
© 2021 Union for International Cancer Control.
All Science Journal Classification (ASJC) codes
- Cancer Research