Hong Cheng William, Reddy Chandana A, Wilkinson D Allan, Klein Eric A, Ciezki Jay P
Lerner College of Medicine, Cleveland Clinic, Cleveland, OH.
Department of Radiation Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH.
J Contemp Brachytherapy. 2015 Feb;7(1):17-22. doi: 10.5114/jcb.2015.48875. Epub 2015 Feb 4.
To examine the influence of zone-specific dosimetry on outcomes during permanent prostate implantation (PI), where the peripheral zone (PZ) and transitional zone (TZ) may receive varying radiation doses.
Four hundred and sixteen patients treated with I-125 PI (target dose: 144 Gy) between 1996 and 2003 were included in this Institutional Review Board (IRB) approved, retrospective analysis. Whole prostate (WP), TZ, and PZ were contoured, and zone-specific D90 and V100 were computed. Their influence on biochemical failure (BF) was evaluated using Cox proportional hazards analysis.
The median age and initial prostate-specific antigen (PSA) was 68 years and 6.1 ng/ml, respectively, and the median follow-up time was 8.8 years. There were 329 subjects with Gleason score (GS) 6 disease (79.1%), and 82 subjects had GS 7 disease (19.7%). Androgen deprivation therapy (ADT) was used in 20.4% of patients. Median D90 and V100% in the WP, PZ, and TZ were 141.2 Gy, 156.1 Gy, and 134.5 Gy; and 88.8%, 93.3%, and 84.2%, respectively. Ten-year rates for biochemical recurrence-free survival, distant metastasis-free survival, and prostate cancer-specific mortality were 82.4%, 92.4%, and 0.97% respectively. Only initial PSA, GS7+ disease, ADT, and PSA frequency were significant on multivariate analysis. Ten-year rates of grade 3 or higher GU and GI toxicity was 10.9% and 1.8%, respectively. TZ V200 and TZ V300 were significantly associated with late genitourinary toxicity.
The TZ received significantly lower doses of radiation compared to the PZ. On multivariate analysis, no dosimetric parameter was associated with efficacy. Higher TZ doses may be associated with higher late GU toxicity without improving efficacy.
探讨区域特异性剂量测定对永久性前列腺植入术（PI）治疗效果的影响，在此过程中，外周区（PZ）和移行区（TZ）可能会接受不同的辐射剂量。
本回顾性分析纳入了1996年至2003年间接受I-125 PI治疗（目标剂量：144 Gy）的416例患者，该研究经机构审查委员会（IRB）批准。勾勒出整个前列腺（WP）、TZ和PZ的轮廓，并计算区域特异性D90和V100。使用Cox比例风险分析评估它们对生化失败（BF）的影响。
中位年龄和初始前列腺特异性抗原（PSA）分别为68岁和6.1 ng/ml，中位随访时间为8.8年。有329例Gleason评分（GS）为6分的患者（79.1%），82例GS为7分的患者（19.7%）。20.4%的患者使用了雄激素剥夺治疗（ADT）。WP、PZ和TZ的中位D90和V100%分别为141.2 Gy、156.1 Gy和134.5 Gy；以及88.8%、93.3%和84.2%。10年无生化复发生存率、无远处转移生存率和前列腺癌特异性死亡率分别为82.4%、92.4%和0.97%。多因素分析显示，只有初始PSA、GS7 +疾病、ADT和PSA频率具有显著性。3级或更高等级的泌尿生殖系统（GU）和胃肠道（GI）毒性的10年发生率分别为10.9%和1.8%。TZ V200和TZ V300与晚期泌尿生殖系统毒性显著相关。
与PZ相比，TZ接受的辐射剂量显著更低。多因素分析显示，没有剂量测定参数与疗效相关。较高的TZ剂量可能与较高的晚期GU毒性相关，而不会提高疗效。
