Karasawa Kumiko, Omatsu Tokuhiko, Shiba Shintaro, Irie Daisuke, Wakatsuki Masaru, Fukuda Shigekazu
Department of Radiation Oncology, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan.
National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba-city, Chiba, 263-8555, Japan.
Radiat Oncol. 2020 Nov 13;15(1):265. doi: 10.1186/s13014-020-01713-1.
Our institute initiated carbon ion radiotherapy research for patients with stage I breast cancer in April 2013. The purpose of this article is to evaluate the treatment outcome of cases treated outside clinical trial up to May 2020.
Eligibility criteria of the patients were having untreated stage I breast cancer and being unsuitable for operation for physical or mental reasons. The irradiated volume was defined as the gross tumor including intraductal components. The dose escalation study was initially conducted four times a week for a total of 52.8 Gy [relative biological efficacy (RBE)]. After confirming that adverse effects were within acceptable range, the total dose was increased to 60.0 Gy (RBE).
Between April 2013 and November 2015, 14 cases were treated. The median follow up period was 61 months. No adverse toxicities were observed except for grade 1 acute skin reaction in 10 cases. The time required from carbonion radiotherapy to tumor disappearance was 3 months in 1 case, 6 months in 3 cases, 12 months in 4 cases, and 24 months in 5 cases. The third case developed local recurrence 6 months after radiotherapy. Twelve patients with luminal subtype received 5-year endocrine therapy. Thirteen of 14 tumors have been maintaining complete response with excellent cosmetic results.
The time from carbon ion radiotherapy to tumor disappearance was longer than expected, but complete tumor disappearance was observed except for one high-grade case. With careful patient selection, carbonion radiotherapy in patients with stage I breast cancer is deemed effective and safe, and further research is recommended.
我院于2013年4月启动了针对I期乳腺癌患者的碳离子放射治疗研究。本文旨在评估截至2020年5月在临床试验之外接受治疗的病例的治疗结果。
患者的入选标准为患有未经治疗的I期乳腺癌且因身体或精神原因不适宜手术。照射体积定义为包括导管内成分的大体肿瘤。剂量递增研究最初每周进行4次，总剂量为52.8 Gy[相对生物效应（RBE）]。在确认不良反应在可接受范围内后，总剂量增加至60.0 Gy（RBE）。
2013年4月至2015年11月期间，共治疗了14例患者。中位随访期为61个月。除10例出现1级急性皮肤反应外，未观察到其他不良毒性反应。1例患者碳离子放射治疗至肿瘤消失的时间为3个月，3例为6个月，4例为12个月，5例为24个月。第3例患者在放疗后6个月出现局部复发。12例管腔亚型患者接受了5年内分泌治疗。14例肿瘤中有13例一直保持完全缓解，美容效果极佳。
碳离子放射治疗至肿瘤消失的时间比预期长，但除1例高级别病例外均观察到肿瘤完全消失。经过仔细的患者选择，I期乳腺癌患者的碳离子放射治疗被认为是有效且安全的，建议进一步开展研究。
