The Japanese breast cancer society clinical practice guidelines for radiation treatment of breast cancer, revised version of 2018 edition

The website version of The Japanese Breast Cancer Society Clinical Practice Guideline for Radiation Treatment of Breast Cancer was revised three times after publication of the original 2018 version. We made major revisions for CQ8 (breast reconstruction), and minor revisions for several CQ/BQ/FQs. In this report, we summarize some important revision points of radiation therapy section of the guideline, and introduce the recommendations for the radiation therapy of breast cancer patients during the COVID-19 pandemic. We hope that this report will be helpful for all clinicians who are engaged in breast cancer treatment. (author)