BACKGROUND Using a prospectively collected institutional database, we compared rectal toxicity following high dose rate (HDR) brachytherapy as monotherapy relative to dose-escalated external beam radiotherapy (EBRT) for patients with localized prostate cancer. METHODS 2683 patients treated with HDR or EBRT between 1994 and 2017 were included. HDR fractionation was 38 Gy/4 fractions (n = 321), 24 Gy/2 (n = 96), or 27 Gy/2 (n = 128). EBRT patients received a median dose of 75.6 Gy in 1.8 Gy fractions [range 70.2-82.8 Gy], using either 3D conformal or intensity modulated radiotherapy (IMRT). EBRT patients underwent 3D image guidance via an off-line adaptive process. RESULTS Median follow-up was 7.5 years (7.4 years for EBRT and 7.9 years for HDR). 545 patients (20.3%) received HDR brachytherapy and 2138 (79.7%) EBRT. 69.1% of EBRT patients received IMRT. Compared to EBRT, HDR was associated with decreased rates of acute grade ≥2 diarrhea (0.7% vs. 4.5%, p < 0.001), rectal pain/tenesmus (0.6% vs. 7.9%, p < 0.001), and rectal bleeding (0% vs. 1.6%, p = 0.001). Rates of chronic grade ≥2 rectal bleeding (1.3% vs. 8.7%, p < 0.001) and radiation proctitis (0.9% vs. 3.3%, p = 0.001) favored HDR over EBRT. Rates of any chronic rectal toxicity grade ≥2 were 2.4% vs. 10.5% (p < 0.001) for HDR versus EBRT, respectively. In those treated with IMRT, acute and chronic rates of any grade ≥2 GI toxicity were significantly reduced but remained significantly greater than those treated with HDR. CONCLUSIONS In appropriately selected patients with localized prostate cancer undergoing radiation therapy, HDR brachytherapy as monotherapy is an effective strategy for reducing rectal toxicity.

中文翻译：

---

与剂量递增的外照射放疗相比，高剂量率近距离放疗作为单一疗法治疗局部前列腺癌的患者的直肠毒性发生率

背景 使用前瞻性收集的机构数据库，我们比较了高剂量率 (HDR) 近距离放疗作为单一疗法与剂量递增的外照射放疗 (EBRT) 对局部前列腺癌患者的直肠毒性。方法 纳入 1994 年至 2017 年间接受 HDR 或 EBRT 治疗的 2683 名患者。HDR 分割为 38 Gy/4 分割 (n = 321)、24 Gy/2 (n = 96) 或 27 Gy/2 (n = 128)。EBRT 患者使用 3D 适形或调强放疗 (IMRT) 接受 75.6 Gy 的中位剂量，分 1.8 Gy [范围 70.2-82.8 Gy]。EBRT 患者通过离线自适应过程接受 3D 图像引导。结果 中位随访时间为 7.5 年（EBRT 为 7.4 年，HDR 为 7.9 年）。545 名患者 (20.3%) 接受了 HDR 近距离放射治疗和 2138 名 (79.7%) EBRT。69. 1% 的 EBRT 患者接受了 IMRT。与 EBRT 相比，HDR 与急性≥2 级腹泻（0.7% 对 4.5%，p < 0.001）、直肠疼痛/里急后重（0.6% 对 7.9%，p < 0.001）和直肠出血的发生率降低有关（ 0% 与 1.6%，p = 0.001）。慢性≥2 级直肠出血（1.3% 对 8.7%，p < 0.001）和放射性直肠炎（0.9% 对 3.3%，p = 0.001）的发生率比 EBRT 更有利于 HDR。HDR 与 EBRT 的任何慢性直肠毒性等级≥2 的发生率分别为 2.4% 和 10.5% (p < 0.001)。在接受 IMRT 治疗的患者中，任何≥2 级胃肠道毒性的急性和慢性发生率均显着降低，但仍显着高于接受 HDR 治疗的患者。CONCLUSIONS In appropriately selected patients with localized prostate cancer undergoing radiation therapy,