Introduction
Iodine-125 (125I) brachytherapy (BT) alone for intermediate-risk (IR) prostate adenocarcinoma (PCA) is controversial. The purpose of the study was to investigate potential predictive factors in selected IR-PCA patients treated with BT.

Material and methods
Among 547 patients treated with 125I BT between 2003 and 2013, 149 IR-PCA cases were selected according to NCCN classification after an additional exclusion of patients with prostate specific antigen (PSA) > 15 ng/ml and ISUP group 3. A relapse was defined as a biochemical failure, using ASTRO Phoenix definition, or a relapse identified on imaging. Survival curves were estimated with Kaplan-Meier method. Potential prognostic variables including EAU/ESTRO/SIOG guidelines eligibility criteria were analyzed using univariate and Cox’s proportional hazards regression analysis.

Results
Of the 149 IR patients, 112 were classified as favorable, with 69 cases eligible to BT according to EAU/ESTRO/SIOG guidelines, and 37 patients were identified as unfavorable as per NCCN. Androgen deprivation therapy (ADT) was applied in 6 patients only. Percentage of positive biopsy cores were ≤ 33% and  50% for 119 and 11 patients, respectively. With a median follow-up of 8.5 years, 30 patients experienced a relapse. 10-year overall survival, progression-free survival (PFS), and relapse-free survival (RFS) were 84% (95% CI: 75-90%), 66% (95% CI: 56-75%), and 77% (95% CI: 67-84%), respectively. Failure to meet EAU/ESTRO/SIOG criteria was significantly associated with a lower RFS (p = 0.0267, HR = 2.37 [95% CI: 1.10-5.08%]).

Conclusions
Brachytherapy is an effective treatment for selected IR-PCA cases. Patients who were not eligible according to EAU/ESTRO/SIOG guidelines demonstrated a lower RFS.



中文翻译：

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根据 EAU/ESTRO/SIOG 指南对中危前列腺癌患者进行独家碘 125 近距离放射治疗的资格标准：对无复发生存期的影响

前言
Iodine-125 (125I) 近距离放射治疗 (BT) 单独治疗中危 (IR) 前列腺腺癌 (PCA) 存在争议。该研究的目的是调查接受 BT 治疗的选定 IR-PCA 患者的潜在预测因素。

材料与方法
在 2003 年至 2013 年期间接受 125I BT 治疗的 547 例患者中，在额外排除前列腺特异性抗原 (PSA) > 15 ng/ml 和 ISUP 组 3 的患者后，根据 NCCN 分类选择了 149 例 IR-PCA 病例。定义为复发作为生化失败，使用 ASTRO Phoenix 定义，或在成像上确定的复发。使用 Kaplan-Meier 方法估计生存曲线。使用单变量和 Cox 的比例风险回归分析对包括 EAU/ESTRO/SIOG 指南资格标准在内的潜在预后变量进行了分析。

结果
在 149 名 IR 患者中，112 名被归类为有利，69 名根据 EAU/ESTRO/SIOG 指南符合 BT 标准，37 名患者根据 NCCN 被确定为不利。仅在 6 名患者中应用了雄激素剥夺疗法 (ADT)。119 名和 11 名患者的阳性活检核心百分比分别为 ≤ 33% 和  50%。中位随访 8.5 年，30 名患者复发。10 年总生存期、无进展生存期 (PFS) 和无复发生存期 (RFS) 分别为 84% (95% CI: 75-90%)、66% (95% CI: 56-75%) 和分别为 77%（95% CI：67-84%）。未能满足 EAU/ESTRO/SIOG 标准与较低的 RFS 显着相关（p = 0.0267，HR = 2.37 [95% CI：1.10-5.08%]）。

结论
近距离放射治疗是对选定的 IR-PCA 病例的有效治疗。根据 EAU/ESTRO/SIOG 指南不符合条件的患者表现出较低的 RFS。