PURPOSE SABR offers an effective treatment option for clinically localized prostate cancer. Here we report the dosimetric predictors of late toxicity and quality of life (QOL) in a pooled cohort of patients from four phase II trials. METHODS The combined cohort included all three prostate cancer risk groups. The prescription dose was 35-40 Gy in 5 fractions. Toxicity (CTCAE) and QOL (EPIC) were collected. Multiple dosimetric parameters for the bladder, rectum and penile bulb were collected. Univariate (UVA) followed by multivariate (MVA) logistic regression analysis was conducted to search for significant dosimetric predictors of late GI/GU toxicity, or minimal clinically important change in the relevant QOL domain. RESULTS 258 patients were included with median follow up of 6.1 years. For QOL, bladder Dmax, V38, D1cc, D2cc, D5cc and rectal V35 were predictors of urinary and bowel MCIC on UVA. On MVA, only bladder V38 remained significant. For late toxicity, various parameters were significant on UVA but only rectal Dmax, V38 and bladder D2cc were significant predictors on MVA. CONCLUSIONS This report confirms that the high-dose regions in the bladder and rectum are more significant predictors of late toxicity and QOL after prostate SABR compared to low-dose regions. Caution must be taken to avoid high doses and hotspots in those organs.

中文翻译：

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前列腺立体定向消融放疗后毒性和生活质量的剂量学预测因子

目的 SABR 为临床局限性前列腺癌提供了一种有效的治疗选择。在这里，我们报告了来自四项 II 期试验的合并患者队列中晚期毒性和生活质量 (QOL) 的剂量学预测因素。方法 联合队列包括所有三个前列腺癌风险组。处方剂量为 35-40 Gy，分 5 次服用。收集毒性 (CTCAE) 和 QOL (EPIC)。收集了膀胱、直肠和阴茎球的多个剂量学参数。进行单变量 (UVA) 和多变量 (MVA) 逻辑回归分析以寻找晚期 GI/GU 毒性的显着剂量学预测因子，或相关 QOL 域中最小的临床重要变化。结果 258 名患者被纳入，中位随访时间为 6.1 年。对于 QOL、膀胱 Dmax、V38、D1cc、D2cc，D5cc 和直肠 V35 是 UVA 下泌尿和肠道 MCIC 的预测因子。在 MVA 上，只有膀胱 V38 仍然显着。对于晚期毒性，各种参数对 UVA 都很重要，但只有直肠 Dmax、V38 和膀胱 D2cc 是对 MVA 的重要预测因子。结论 本报告证实，与低剂量区域相比，膀胱和直肠中的高剂量区域是前列腺 SABR 后晚期毒性和 QOL 的更重要预测因子。必须小心避免这些器官中的高剂量和热点。结论 本报告证实，与低剂量区域相比，膀胱和直肠中的高剂量区域是前列腺 SABR 后晚期毒性和 QOL 的更重要预测因子。必须小心避免这些器官中的高剂量和热点。结论 本报告证实，与低剂量区域相比，膀胱和直肠中的高剂量区域是前列腺 SABR 后晚期毒性和 QOL 的更重要预测因子。必须小心避免这些器官中的高剂量和热点。