Impact of dose to the bladder trigone on long-term urinary function after high-dose intensity modulated radiation therapy for localized prostate cancer.
Impact of dose to the bladder trigone on long-term urinary function after high-dose intensity modulated radiation therapy for localized prostate cancer.
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DOI：
10.1016/j.ijrobp.2013.10.042
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发表时间：
2014-02-01
期刊：
影响因子：
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通讯作者：
Jackson A
中科院分区：
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作者：
Ghadjar P;Zelefsky MJ;Spratt DE;Munck af Rosenschöld P;Oh JH;Hunt M;Kollmeier M;Happersett L;Yorke E;Deasy JO;Jackson A
目的：探讨局部前列腺癌患者高剂量调强放疗(IMRT)后生殖道(GU)毒性与GU盆腔结构计划剂量-体积参数之间的潜在联系。采用国际前列腺症状评分(IPSS)问卷对268例患者进行治疗，剂量为86.4Gy48次。分析全膀胱、膀胱壁、尿路、膀胱三角的剂量体积直方图。GU毒性的主要终点是IPSS总和比基线增加10分≥。单因素分析采用Kaplan-Meier方法，多因素分析采用Cox比例风险模型。中位随访期5年(3~7.7年)。39例患者在随访期间IPSS总和增加≥为10；84%的患者在5年内仍无事件发生。单因素分析显示，基线IPSS总和较低(P=0.006)、三角区V90(P=0.006)、三角区最大剂量(P=0.003)与IPSS总和增加≥10显著相关。多因素分析显示，基线IPSS总和较低(P=0.009)、三角区最大剂量增加(P=0.005)与IPSS总和增加显著相关。有68例患者同时具有较高的基础IPSS总和和较低的三角区最大剂量，并被定义为高危；68例患者同时具有较高的基线IPSS总和和较低的三角最大剂量，被定义为发生IPSS总和增加≥10的低风险患者。在随访期间，将热点应用于膀胱三角区与IPSS的相关变化显著相关。减少对下膀胱的辐射剂量，特别是膀胱三角的辐射剂量似乎与晚期GU毒性的减少有关。
To determine the potential association between genitourinary (GU) toxicity and planning dose-volume parameters for GU pelvic structures after high-dose intensity-modulated radiotherapy (IMRT) in localized prostate cancer patients. 268 patients who underwent IMRT to a prescribed dose of 86.4 Gy in 48 fractions during 06/2004–12/2008 were evaluated with the International Prostate Symptom Score (IPSS) questionnaire. Dose volume histograms of the whole bladder, bladder wall, urethra, and bladder trigone were analyzed. The primary endpoint for GU toxicity was an IPSS sum increase ≥10 points over baseline. Univariate and multivariate analyses were done by Kaplan-Meier method and Cox proportional hazard models, respectively. Median follow-up was 5 years (range, 3–7.7 years). Thirty-nine patients experienced an IPSS sum increase ≥10 during follow-up; 84% remained event free at 5 years. After univariate analysis, lower baseline IPSS sum (P=0.006), the V90 of the trigone (P=0.006), and the maximal dose to the trigone (P=0.003) were significantly associated with an IPSS sum increase ≥10. After multivariate analysis, lower baseline IPSS sum (P=0.009) and increased maximal dose to the trigone (P=0.005) remained significantly associated. Seventy-two patients had both a lower baseline IPSS sum and a higher maximal dose to the trigone and were defined as high-risk and 68 patients had both a higher baseline IPSS sum and a lower maximal dose to the trigone and were defined as low-risk for development of an IPSS sum increase ≥10. Twenty-one of 72 high-risk (29%) and 5 of 68 low-risk (7%) patients experienced an IPSS sum increase ≥10 (P=0.001; odds ratio, 5.19). The application of hot spots to the bladder trigone was significantly associated with relevant changes in IPSS during follow-up. Reduction of radiation dose to the lower bladder and specifically the bladder trigone appears to be associated with a reduction in late GU toxicity.