Department of Radiation Oncology, Kanagawa Cancer Center, Asahi-ku, Yokohama, Kanagawa, 241-8515, Japan.
Radiat Oncol. 2020 May 27;15(1):127. doi: 10.1186/s13014-020-01575-7.
Carbon-ion radiotherapy (CIRT) for prostate cancer was initiated at Kanagawa Cancer Center in 2015. The present study analyzed the preliminary clinical outcomes of CIRT for prostate cancer.
The clinical outcomes of 253 patients with prostate cancer who were treated with CIRT delivered using the spot scanning method between December 2015 and December 2017 were retrospectively analyzed. The irradiation dose was set at 51.6 Gy (relative biological effectiveness) delivered in 12 fractions over 3 weeks. Biochemical relapse was defined using the Phoenix definition. Toxicities were assessed according to CTCAE version 4.0.
The median patient age was 70 (47-86) years. The median follow-up duration was 35.3 (4.1-52.9) months. According to the D'Amico classification system, 8, 88, and 157 patients were classified as having low, intermediate, and high risks, respectively. Androgen deprivation therapy was administered in 244 patients. The biochemical relapse-free rate in the low-, intermediate-, and high-risk groups at 3 years was 87.5, 88.0, and 97.5%, respectively (P = 0.036). Grade 2 acute urinary toxicity was observed in 12 (4.7%) patients. Grade 2 acute rectal toxicity was not observed. Grade 2 late urinary toxicity and grade 2 late rectal toxicity were observed in 17 (6.7%) and 3 patients (1.2%), respectively. Previous transurethral resection of the prostate was significantly associated with late grade 2 toxicity in univariate analysis. The predictive factor for late rectal toxicity was not detected.
The present study demonstrated that CIRT using the spot scanning method for prostate cancer produces favorable outcomes.
碳离子放疗（CIRT）于 2015 年在神奈川癌症中心开始用于前列腺癌的治疗。本研究分析了前列腺癌 CIRT 的初步临床结果。
回顾性分析了 2015 年 12 月至 2017 年 12 月期间采用点扫描法进行 CIRT 治疗的 253 例前列腺癌患者的临床结果。照射剂量设定为 51.6Gy（相对生物效应），分 12 次，3 周内完成。采用凤凰定义来定义生化复发。根据 CTCAE 第 4.0 版评估毒性。
患者中位年龄为 70（47-86）岁。中位随访时间为 35.3（4.1-52.9）个月。根据 D'Amico 分类系统，8、88 和 157 例患者分别归类为低、中、高危。244 例患者接受了雄激素剥夺治疗。低、中、高危组 3 年生化无复发生存率分别为 87.5%、88.0%和 97.5%（P=0.036）。12 例（4.7%）患者出现 2 级急性尿毒性。未观察到 2 级急性直肠毒性。17 例（6.7%）和 3 例（1.2%）患者分别出现 2 级迟发性尿毒性和 2 级迟发性直肠毒性。单因素分析显示，既往经尿道前列腺切除术与迟发性 2 级毒性显著相关。未检测到预测直肠毒性的因素。
本研究表明，采用点扫描法的前列腺癌 CIRT 可获得良好的结果。
