Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York.
Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York.
Int J Radiat Oncol Biol Phys. 2014 Oct 1;90(2):312-9. doi: 10.1016/j.ijrobp.2014.06.031.
To identify an anatomic structure predictive for acute (AUT) and late (LUT) urinary toxicity in patients with prostate cancer treated with low-dose-rate brachytherapy (LDR) with or without external beam radiation therapy (EBRT).
From July 2002 to January 2013, 927 patients with prostate cancer (median age, 66 years) underwent LDR brachytherapy with Iodine 125 (n=753) or Palladium 103 (n=174) as definitive treatment (n=478) and as a boost (n=449) followed by supplemental EBRT (median dose, 50.4 Gy). Structures contoured on the computed tomographic (CT) scan on day 0 after implantation included prostate, urethra, bladder, and the bladder neck, defined as 5 mm around the urethra between the catheter balloon and the prostatic urethra. AUT and LUT were assessed with the Common Terminology Criteria for Adverse Events, version4. Clinical and dosimetric factors associated with AUT and LUT were analyzed with Cox regression and receiver operating characteristic analysis to calculate area under the receiver operator curve (ROC) (AUC).
Grade ≥2 AUT and grade ≥2 LUT occurred in 520 patients (56%) and 154 patients (20%), respectively. No grade 4 toxicities were observed. Bladder neck D2cc retained a significant association with AUT (hazard ratio [HR], 1.03; 95% confidence interval [CI], 1.03-1.04; P<.0001) and LUT (HR, 1.01; 95% CI, 1.00-1.03; P=.014) on multivariable analysis. In a comparison of bladder neck with the standard dosimetric variables by use of ROC analysis (prostate V100 >90%, D90 >100%, V150 >60%, urethra D20 >130%), bladder neck D2cc >50% was shown to have the strongest prognostic power for AUT (AUC, 0.697; P<.0001) and LUT (AUC, 0.620; P<.001).
Bladder neck D2cc >50% was the strongest predictor for grade ≥2 AUT and LUT in patients treated with LDR brachytherapy. These data support inclusion of bladder neck constraints into brachytherapy planning to decrease urinary toxicity.
在接受低剂量率近距离放射治疗（LDR）联合或不联合外部束放射治疗（EBRT）的前列腺癌患者中，确定与急性（AUT）和晚期（LUT）尿毒性相关的解剖结构。
2002 年 7 月至 2013 年 1 月，927 例前列腺癌患者（中位年龄 66 岁）接受碘 125（n=753）或钯 103（n=174）作为根治性治疗（n=478）和作为辅助治疗（n=449）的 LDR 近距离放射治疗，然后补充 EBRT（中位剂量 50.4Gy）。植入后第 0 天 CT 扫描上勾画的结构包括前列腺、尿道、膀胱和膀胱颈部，定义为尿道导管球囊与前列腺尿道之间 5mm 范围内的尿道。采用通用不良事件术语标准 4.0 评估 AUT 和 LUT。采用 Cox 回归和受试者工作特征（ROC）分析，分析与 AUT 和 LUT 相关的临床和剂量学因素，计算 ROC 曲线下面积（AUC）。
520 例（56%）和 154 例（20%）患者分别发生≥2 级 AUT 和≥2 级 LUT。未观察到 4 级毒性。膀胱颈部 D2cc 与 AUT（风险比[HR]，1.03；95%置信区间[CI]，1.03-1.04；P<.0001）和 LUT（HR，1.01；95% CI，1.00-1.03；P=.014）均有显著相关性。通过 ROC 分析比较膀胱颈部与标准剂量学变量（前列腺 V100>90%，D90>100%，V150>60%，尿道 D20>130%），膀胱颈部 D2cc>50%对 AUT（AUC，0.697；P<.0001）和 LUT（AUC，0.620；P<.001）具有最强的预后预测能力。
在接受 LDR 近距离放射治疗的患者中，膀胱颈部 D2cc>50%是发生≥2 级 AUT 和 LUT 的最强预测因子。这些数据支持将膀胱颈部限制纳入近距离放射治疗计划，以降低尿毒性。
