Sullivan Lisa, Williams Scott G, Tai Keen Hun, Foroudi Farshad, Cleeve L, Duchesne Gillian M
Division of Radiation Oncology, Peter MacCallum Cancer Centre and University of Melbourne, Australia.
Radiother Oncol. 2009 May;91(2):232-6. doi: 10.1016/j.radonc.2008.11.013. Epub 2008 Dec 26.
To evaluate the incidence, timing, nature and outcome of urethral strictures following high dose rate brachytherapy (HDRB) for prostate carcinoma.
Data from 474 patients with clinically localised prostate cancer treated with HDRB were analysed. Ninety percent received HDRB as a boost to external beam radiotherapy (HDRBB) and the remainder as monotherapy (HDRBM). Urethral strictures were graded according to the Common Terminology Criteria for Adverse Events v3.0.
At a median follow-up of 41 months, 38 patients (8%) were diagnosed with a urethral stricture (6-year actuarial risk 12%). Stricture location was bulbo-membranous (BM) urethra in 92.1%. The overall actuarial rate of grade 2 or more BM urethral stricture was estimated at 10.8% (95% CI 7.0-14.9%), with a median time to diagnosis of 22 months (range 10-68 months). All strictures were initially managed with either dilatation (n=15) or optical urethrotomy (n=20). Second line therapy was required in 17 cases (49%), third line in three cases (9%) and 1 patient open urethroplasty (grade 3 toxicity). Predictive factors on multivariate analysis were prior trans-urethral resection of prostate (hazard ratio (HR) 2.81, 95% CI 1.15-6.85, p=0.023); hypertension (HR 2.83, 95% CI 1.37-5.85, p=0.005); and dose per fraction used in HDR (HR for 1 Gy increase per fraction 1.33, 95% CI 1.08-1.64, p=0.008).
BM urethral strictures are the most common late grade 2 or more urinary toxicity following HDR brachytherapy for prostate cancer. Most are manageable with minimally invasive procedures. Both clinical and dosimetric factors appear to influence the risk of stricture formation.
评估高剂量率近距离放射治疗（HDRB）前列腺癌后尿道狭窄的发生率、发生时间、性质及转归。
分析474例接受HDRB治疗的临床局限性前列腺癌患者的数据。90%的患者接受HDRB作为外照射放疗的补充（HDRBB），其余患者接受单一疗法（HDRBM）。根据不良事件通用术语标准v3.0对尿道狭窄进行分级。
中位随访41个月时，38例患者（8%）被诊断为尿道狭窄（6年精算风险为12%）。92.1%的狭窄位于球膜部（BM）尿道。2级或更高级别的BM尿道狭窄的总体精算率估计为10.8%（95%CI 7.0 - 14.9%），诊断的中位时间为22个月（范围10 - 68个月）。所有狭窄最初均采用扩张术（n = 15）或光学尿道切开术（n = 20）处理。17例（49%）患者需要二线治疗，3例（9%）需要三线治疗，1例患者接受开放性尿道成形术（3级毒性）。多因素分析的预测因素为既往经尿道前列腺切除术（风险比（HR）2.81，95%CI 1.15 - 6.85，p = 0.023）；高血压（HR 2.83，95%CI 1.37 - 5.85，p = 0.005）；以及HDR中每分次使用的剂量（每分次增加1 Gy的HR为1.33，95%CI 1.08 - 1.64，p = 0.008）。
BM尿道狭窄是HDR近距离放射治疗前列腺癌后最常见的2级或更高级别的晚期泌尿系统毒性反应。大多数狭窄可通过微创手术处理。临床和剂量学因素似乎都影响狭窄形成的风险。
