Radiation Oncology, Geneva University Hospital, Geneva, Switzerland; Faculty of Medicine, Geneva University, Geneva, Switzerland; Radiation Oncology, Oncology Institute of Southern Switzerland (IOSI), EOC, Bellinzona, Switzerland; Facoltà Scienze Biomediche Università della Svizzera Italiana (USI), Lugano, Switzerland.
Department of Biomedical Sciences, Humanitas University, Pieve Emanuele, Milan, Italy; Department of Radiotherapy and Radiosurgery IRCCS Humanitas Research Hospital, Rozzano, Milan, Italy.
Radiother Oncol. 2024 May;194:110181. doi: 10.1016/j.radonc.2024.110181. Epub 2024 Feb 24.
To assess in a prospective, multicenter, single-arm phase I/II study the early safety and efficacy profile of single fraction urethra-sparing stereotactic body radiotherapy (SBRT) for men with localized prostate cancer.
Patients with low- and intermediate-risk localized prostate cancer without significant tumor in the transitional zone were recruited. A single-fraction of 19 Gy was delivered to the prostate, with 17 Gy dose-reduction to the urethra. Intrafraction motion was monitored using intraprostatic electromagnetic transponders with intra-fraction correction of displacements exceeding 3 mm. Genitourinary (GU), gastrointestinal (GI), and sexual toxicity during the first 18 months were evaluated using the CTCAE v4.0 grading scale. Quality of life was assessed using the International Prostate Symptom Score, the Expanded Prostate Cancer Index composite 26 score, and the International Index of Erectile Function score.
Among the 45 patients recruited in 5 centers between 2017 and 2022, 43 received the single fraction without protocol deviations, and 34 had a minimal follow-up of 18 months. The worst GU toxicity was observed at day-5 after SBRT (42.5 % and 20 % with grade 1 and 2, respectively), returning to baseline at week-12 and month-6 (<3% with grade 2), with a 12 % grade 2 flare at month 18. Gl toxicity was mild in the acute phase, with no grade ≥ 2 events (12 % grade 1 at month 6). Grade-3 proctitis was observed in one patient at month 12, with < 3 % grade 2 toxicity at month 18. Mean GU and GI bother scores showed a decline at day 5, a complete recovery at month 6, and a flare between month 12 and 18. Mean PSA dropped from 6.2 ng/ml to 1.2 ng/ml at month 18 and 0.7 ng/ml at month 24. After a median follow-up time of 26 months, 3 biochemical failures (7 %) were observed at month 17, 21 and 30.
In this multicenter phase I/II trial, we demonstrated that a 19 Gy single-fraction urethra-sparing SBRT is feasible and associated with an acceptable toxicity rate, mostly returning to the baseline at week-12 and with a symptoms flare between months 12 and 18. Longer follow-up is needed to assess the potential long-term adverse effects and the disease control efficacy.
在一项前瞻性、多中心、单臂 I/II 期研究中，评估对于局限性前列腺癌患者，单次分割尿道保留的立体定向体部放疗（SBRT）的早期安全性和疗效概况。
招募了低危和中危局限性前列腺癌且移行区无明显肿瘤的患者。给予前列腺单次 19 Gy，尿道剂量减少至 17 Gy。使用前列腺内电磁传感器监测分次内运动，并对超过 3mm 的位移进行分次内校正。使用 CTCAE v4.0 分级标准评估 18 个月内的泌尿生殖系统（GU）、胃肠道（GI）和性毒性。使用国际前列腺症状评分、前列腺癌指数综合 26 评分和国际勃起功能指数评分评估生活质量。
在 2017 年至 2022 年间 5 个中心招募的 45 例患者中，43 例按方案接受了单次分割，34 例有至少 18 个月的最小随访。SBRT 后第 5 天观察到最严重的 GU 毒性（分别为 42.5%和 20%为 1 级和 2 级），第 12 周和第 6 个月恢复至基线（<3%为 2 级），第 18 个月时出现 12%的 2 级 flare）。急性 GI 毒性轻微，无≥2 级事件（6 个月时 12%为 1 级）。1 例患者在第 12 个月时出现 3 级直肠炎，第 18 个月时<3%为 2 级毒性。GU 和 GI 烦恼评分在第 5 天下降，在第 6 个月完全恢复，在第 12 至 18 个月时 flare。平均 PSA 在第 18 个月时从 6.2ng/ml 降至 1.2ng/ml，在第 24 个月时降至 0.7ng/ml。中位随访 26 个月后，在第 17、21 和 30 个月时观察到 3 例生化失败（7%）。
在这项多中心 I/II 期试验中，我们证明了单次 19 Gy 分割尿道保留的 SBRT 是可行的，并且具有可接受的毒性发生率，大多数在第 12 周恢复至基线，并且在第 12 至 18 个月时出现症状 flare。需要更长时间的随访来评估潜在的长期不良影响和疾病控制效果。
