Introduction
To compare brachytherapy (BT) boost of low-dose-rate (LDR) and high-dose-rate (HDR) techniques in patients diagnosed with intermediate-risk prostate cancer.

Material and methods
Between January 2005 and February 2018, 142 patients (50 LDR and 92 HDR) with intermediate-risk prostate cancer were treated with a BT boost, and retrospectively analyzed. Prescribed dose was 45 Gy with external beam radiotherapy (EBRT) plus 100-108 Gy with LDR-BT, and 60 Gy with EBRT plus one fraction of 10 Gy with HDR-BT. 99% of patients received androgen deprivation therapy (ADT) for 6 months. Primary endpoint was to compare LDR and HDR boosts in terms of biochemical progression-free survival (bPFS). Secondary endpoint, after re-classifying patients into “favorable” and “unfavorable” sub-groups, was to analyze differences with a similar treatment intensity.

Results
Median overall follow-up for the total cohort was 66.5 months (range, 16-185 months). There were no significant differences in bPFS, overall survival, cause specific survival, local failure, lymph node failure, or distant failure when LDR or HDR was employed. bPFS at 90 months was 100% for favorable, and 89% and 85% for unfavorable patients at 60 months and 90 months, respectively (log-rank test, p = 0.017). The crude incidence of genitourinary acute and chronic toxicity grade 3 was 0.7% and 4%, respectively. Twelve patients (8%) had chronic rectal hemorrhage grade 2, in whom argon was applied (4 LDR and 8 HDR).

Conclusions
Combined treatment is an excellent therapeutic option in patients with intermediate-risk prostate carcinoma, with similar results in both LDR and HDR approaches and very low toxicities. Importantly, the current literature has indicated that unfavorable-risk patients belong to a different category, and should be treated as patients with high-risk factors. Therefore, the stratification and identification of both risk groups is extremely relevant.



中文翻译：

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对接受放射治疗的中危前列腺癌患者进行低/高剂量率近距离放射治疗：单一机构团队经验的长期结果

简介
比较低剂量率 (LDR) 和高剂量率 (HDR) 技术对诊断为中度风险前列腺癌患者的近距离放射治疗 (BT) 增强。

材料与方法
2005 年 1 月至 2018 年 2 月期间，142 名中危前列腺癌患者（50 名 LDR 和 92 名 HDR）接受了 BT 加强治疗，并进行了回顾性分析。外照射放疗 (EBRT) 的处方剂量为 45 Gy，LDR-BT 的处方剂量为 100-108 Gy，EBRT 的处方剂量为 60 Gy，HDR-BT 的处方剂量为 10 Gy 的一部分。99% 的患者接受了为期 6 个月的雄激素剥夺治疗 (ADT)。主要终点是比较 LDR 和 HDR 在生化无进展生存期 (bPFS) 方面的提升。次要终点是在将患者重新分类为“有利”和“不利”亚组后，分析具有相似治疗强度的差异。

结果
整个队列的中位总体随访时间为 66.5 个月（范围 16-185 个月）。当采用 LDR 或 HDR 时，bPFS、总生存期、特定原因生存期、局部衰竭、淋巴结衰竭或远处衰竭没有显着差异。90 个月时的 bPFS 为 100%，对于 60 个月和 90 个月的不良患者，分别为 89% 和 85%（对数秩检验，p = 0.017）。泌尿生殖系统急性和慢性毒性 3 级的粗发生率分别为 0.7% 和 4%。12 名患者 (8%) 患有 2 级慢性直肠出血，其中使用了氩气（4 名 LDR 和 8 名 HDR）。

结论
对于中危前列腺癌患者，联合治疗是一种极好的治疗选择，LDR 和 HDR 方法的结果相似，并且毒性非常低。重要的是，目前的文献表明，不利风险患者属于不同的类别，应被视为具有高风险因素的患者。因此，两个风险组的分层和识别是非常相关的。