Department of Radiation Oncology, Shanghai Proton and Heavy Ion Center, Shanghai, China.
Shanghai Key Laboratory of Radiation Oncology (20dz2261000), Shanghai, China.
J Radiat Res. 2023 Nov 21;64(6):933-939. doi: 10.1093/jrr/rrad068.
This study aimed to evaluate the oncological outcomes and safety of carbon ion re-irradiation with pencil beam scanning (PBS) delivery technique for previously irradiated and unresectable locally recurrent rectal cancer (LRRC). Between June 2017 and September 2021, 24 patients of unresectable LRRC with prior pelvic photon radiotherapy who underwent carbon ion re-irradiation at our institute were retrospectively analyzed. Carbon ion radiotherapy was delivered by raster scanning with a median relative biological effectiveness-weighted dose of 72 Gy in 20 fractions. Weekly CT reviews were carried out, and offline adaptive replanning was performed whenever required. The median follow-up duration was 23.8 months (range, 6.2-47.1 months). At the last follow-up, two patients had a local disease progression, and 11 patients developed distant metastases. The 1- and 2-year local control, progression-free survival and overall survival rates were 100 and 93.3%, 70.8 and 45.0% and 86.7 and 81.3%, respectively. There were no Grade 3 or higher acute toxicities observed. Three patients developed Grade 3 late toxicities, one each with gastrointestinal toxicity, skin reaction and pelvic infection. In conclusion, definitive carbon ion re-irradiation with PBS provided superior oncologic results with tolerable toxicities and may be served as a curative treatment strategy in unresectable LRRC.
本研究旨在评估使用铅笔束扫描（PBS）递送技术对先前接受过盆腔光子放射治疗且无法切除的局部复发性直肠癌（LRRC）进行碳离子再放疗的肿瘤学结果和安全性。2017 年 6 月至 2021 年 9 月，对在我院接受碳离子再放疗的 24 例无法切除的局部复发性直肠癌患者进行回顾性分析。碳离子放射治疗采用光栅扫描，中位相对生物学有效加权剂量为 72Gy，共 20 个分次。每周进行 CT 复查，并在需要时进行离线自适应计划调整。中位随访时间为 23.8 个月（范围 6.2-47.1 个月）。末次随访时，有 2 例患者局部疾病进展，11 例患者发生远处转移。1 年和 2 年局部控制率、无进展生存率和总生存率分别为 100%和 93.3%、70.8%和 45.0%以及 86.7%和 81.3%。未观察到 3 级或更高级别的急性毒性。有 3 例患者发生 3 级晚期毒性，分别为胃肠道毒性、皮肤反应和骨盆感染各 1 例。总之，使用 PBS 的确定性碳离子再放疗具有优异的肿瘤学结果，且毒性可耐受，可能是无法切除的局部复发性直肠癌的一种有前途的治疗策略。
