Departments of Radiotherapy and Radiosurgery.
Department of Biomedical Sciences, Humanitas University, Rozzano-Milan, Italy.
Am J Clin Oncol. 2020 Sep;43(9):628-635. doi: 10.1097/COC.0000000000000721.
Stereotactic body radiation treatment represents an intriguing therapeutic option for patients with early-stage prostate cancer. In this phase II study, stereotactic body radiation treatment was delivered by volumetric modulated arc therapy with flattening filter free beams and was gated using real-time electromagnetic transponder system to maximize precision of radiotherapy and, potentially, to reduce toxicities.
Patients affected by histologically proven prostate adenocarcinoma and National Comprehensive Cancer Network (NCCN) intermediate class of risk were enrolled in this phase II study. Beacon transponders were positioned transrectally within the prostate parenchyma 7 to 10 days before simulation computed tomography scan. The radiotherapy schedule was 38 Gy in 4 fractions delivered every other day. Toxicity assessment was performed according to Common Terminology Criteria for Adverse Events (CTCAE), v4.0.
Thirty-six patients were enrolled in this study. Median initial prostate-specific antigen was 7.0 ng/mL (range: 2.3 to 14.0 ng/mL). Median nadir-prostate-specific antigen after treatment was 0.2 ng/mL (range: 0.006 to 4.8 ng/mL). A genitourinary acute toxicity was observed in 21 patients (dysuria grade [G] 1: 41.7%, G2: 16.7%). Gastrointestinal acute toxicity was found in 9 patients (proctitis G1: 19.4%, G2: 5.6%). Late toxicity was mild (genitourinary toxicity G1: 30.6%; G2: 8.3%; gastrointestinal toxicity G1: 13.9%; G2: 19.4%). At a median follow-up time of 41 months, 3 biochemical recurrences were observed (2 local recurrences, 1 distant metastasis). Three-year biochemical recurrence-free survival was 89.8% (International Society of Urologic Pathology Grade Group 2: 100%, Grade Group 3: 77.1%, P=0.042).
Ultrahypofractionated radiotherapy, delivered with flattening filter free-volumetric modulated arc therapy and gated by electromagnetic transponders, is a valid option for intermediate-risk prostate cancer.
立体定向体部放射治疗为早期前列腺癌患者提供了一种很有吸引力的治疗选择。在这项 II 期研究中，使用无均整滤过器的容积调强弧形治疗技术进行立体定向体部放射治疗，并使用实时电磁转发器系统进行门控，以最大限度地提高放射治疗的精度，并可能降低毒性。
本 II 期研究纳入了经组织学证实的前列腺腺癌和国家综合癌症网络（NCCN）中危风险的患者。在模拟 CT 扫描前 7 至 10 天，将 beacon 转发器经直肠放置在前列腺实质内。放射治疗方案为 38 Gy，分 4 次，隔天进行。毒性评估根据不良事件通用术语标准（CTCAE），v4.0 进行。
本研究共纳入 36 例患者。中位初始前列腺特异性抗原为 7.0ng/ml（范围：2.3 至 14.0ng/ml）。治疗后中位前列腺特异性抗原最低值为 0.2ng/ml（范围：0.006 至 4.8ng/ml）。21 例患者出现泌尿生殖系统急性毒性（排尿困难 G1：41.7%，G2：16.7%）。9 例患者出现胃肠道急性毒性（直肠炎 G1：19.4%，G2：5.6%）。晚期毒性较轻（泌尿生殖系统毒性 G1：30.6%；G2：8.3%；胃肠道毒性 G1：13.9%；G2：19.4%）。中位随访时间为 41 个月时，观察到 3 例生化复发（2 例局部复发，1 例远处转移）。3 年生化无复发生存率为 89.8%（国际泌尿病理学会分级组 2：100%，分级组 3：77.1%，P=0.042）。
使用无均整滤过器的容积调强弧形治疗技术进行超分割放射治疗，并通过电磁转发器进行门控，是中危前列腺癌的一种有效治疗选择。
