Survey on use of postmastectomy radiotherapy for breast cancer in China

Purpose: To comprehensively assess the current use of postmastectomy radiotherapy (PMRT) throughout China. Methods and Materials: A questionnaire on the indications and techniques for PMRT for breast cancer was mailed to all 715 radiotherapy centers in mainland China. Results: Of the 715 questionnaires sent out, 210 were answered (29.4%). The median interval between surgery and PMRT was 6 weeks. "Sandwich" sequencing of chemotherapy and PMRT was the most common combination, performed in 75.7% of the responding clinics. Of the respondents, 11.9% used PMRT for T1-T2N0 breast cancer, 63.8% for T1-T2N0 with tumors located in the center or inner quadrant, 87.6% for Stage T1-T2 and one to three positive lymph nodes (LN+), and 97.1% for T3 or Stage III tumors and/or four or more LN+. The supraclavicular region was the most common radiation target used by the respondents (96.2%), followed by the internal mammary chain (85.2%), chest wall (79.0%), and axilla (74.8%). Photon-based tangential fields were the most common technique used for chest wall irradiation (45.8%). The median total dose to each target was 50 Gy, with 2-Gy fractions. Conclusion: A consensus has been reached in China that PMRT is needed for patients with T3 or Stage III disease and/or four or more LN+ and that irradiation to the chest wall and supraclavicular region is necessary in such patients. However, most Chinese radiation centers are also likely to apply PMRT to patients with one to three LN+ and to irradiate the internal mammary chain and the axilla.