Background

The aim of this multi-institutional phase II study was to confirm the safety and the potential efficacy of moderately hypofractionated intensity-modulated radiotherapy (IMRT) with prostate-based image-guidance for Japanese patients.

Methods

Patients with low- or intermediate-risk localized prostate cancer were eligible. Patients with a part of high risk (having only one of the following factors, cT3a, 20 < PSA ≤ 30, or GS = 8 or 9) were also included. Hypofractionated IMRT using daily image-guided technique with prostate matching was performed with a total dose of 70 Gy in 28 fractions. Neoadjuvant hormonal therapy for 4–8 months was mandatory for patients with intermediate or high-risk prostate cancer.

Results

From 20 institutions, 134 patients enrolled. The median follow-up was 5.16 years (range, 1.43–6.47 years). The number of patients with low, intermediate, and high-risk prostate cancer was 20, 80, and 34, respectively. The 5-year overall, biochemical failure-free, and clinical failure-free survival was 94.5%, 96.0%, and 99.2%, respectively. The 5-year biochemical failure-free survival for patients with low-, intermediate-, and high-risk disease was 94.1%, 97.4%, and 93.9%, respectively. The incidences of grade 2 gastrointestinal (GI) and genitourinary (GU) late toxicities at 5 years were 5.3% and 5.3%, respectively. There are no acute or late toxicities ≥ grade 3. Of 124 patients who were followed for up to 5 years, the grade 2 late GU or GI toxicities were 10.5% (90% confidence intervals, 6.3–16.2%, p = 0.0958).

Conclusion

The safety and efficacy of moderately hypofractionated IMRT with prostate-based image-guidance was confirmed among Japanese patients with prostate cancer.

中文翻译：

---

日本多机构采用图像引导技术进行中等大分割调强放射治疗前列腺癌的 II 期研究

背景

这项多机构 II 期研究的目的是确认日本患者采用基于前列腺的图像引导的中度大分割调强放射治疗 (IMRT) 的安全性和潜在疗效。

方法

患有低风险或中风险局限性前列腺癌的患者符合资格。部分高危患者（仅具有以下因素之一，cT3a、20 < PSA ≤ 30，或 GS = 8 或 9）也包括在内。使用每日图像引导技术和前列腺匹配进行大分割 IMRT，分 28 次进行，总剂量为 70 Gy。对于中危或高危前列腺癌患者，必须进行 4-8 个月的新辅助激素治疗。

结果

来自 20 个机构的 134 名患者入组。中位随访时间为 5.16 年（范围：1.43-6.47 年）。低危、中危、高危前列腺癌患者人数分别为20人、80人、34人。 5 年总体、生化无失败和临床无失败生存率分别为 94.5%、96.0% 和 99.2%。低危、中危和高危患者的 5 年生化无失败生存率分别为 94.1%、97.4% 和 93.9%。 5 年时 2 级胃肠道 (GI) 和泌尿生殖系统 (GU) 晚期毒性的发生率分别为 5.3% 和 5.3%。没有≥ 3 级的急性或晚期毒性。在随访长达 5 年的 124 名患者中，2 级晚期 GU 或 GI 毒性为 10.5%（90% 置信区间，6.3-16.2%，p = 0.0958）。

结论

采用基于前列腺的图像引导的中度大分割 IMRT 的安全性和有效性在日本前列腺癌患者中得到证实。