Schiffler Cancer Center/Wheeling Jesuit University, Wheeling, WV 26003, USA.
Int J Radiat Oncol Biol Phys. 2012 Mar 1;82(3):e449-55. doi: 10.1016/j.ijrobp.2011.07.016. Epub 2011 Dec 21.
The necessity of external beam radiotherapy (EBRT) as a supplement to prostate brachytherapy remains unknown. We report brachytherapy outcomes for patients with higher risk features randomized to substantially different supplemental EBRT regimens.
Between December 1999 and June 2004, 247 patients were randomized to 20 Gy vs. 44 Gy EBRT followed by a palladium-103 boost (115 Gy vs. 90 Gy). The eligibility criteria included clinically organ-confined disease with Gleason score 7-10 and/or pretreatment prostate-specific antigen (PSA) level 10-20 ng/mL. The median follow-up period was 9.0 years. Biochemical progression-free survival (bPFS) was defined as a PSA level of ≤0.40 ng/mL after nadir. The median day 0 prescribed dose covering 90% of the target volume was 125.7%; 80 men received androgen deprivation therapy (median, 4 months). Multiple parameters were evaluated for their effect on bPFS.
For the entire cohort, the cause-specific survival, bPFS, and overall survival rates were 97.7%, 93.2%, and 80.8% at 8 years and 96.9%, 93.2%, and 75.4% at 10 years, respectively. The bPFS rate was 93.1% and 93.4% for the 20-Gy and 44-Gy arms, respectively (p = .994). However, no statistically significant differences were found in cause-specific survival or overall survival were identified. When stratified by PSA level of ≤10 ng/mL vs. >10 ng/mL, Gleason score, or androgen deprivation therapy, no statistically significant differences in bPFS were discerned between the two EBRT regimens. On multivariate analysis, bPFS was most closely related to the preimplant PSA and clinical stage. For patients with biochemically controlled disease, the median PSA level was <0.02 ng/mL.
The results of the present trial strongly suggest that two markedly different supplemental EBRT regimens result in equivalent cause-specific survival, bPFS, and overall survival. It is probable that the lack of benefit for a higher supplemental EBRT dose is the result of the high-quality brachytherapy dose distributions.
作为前列腺近距离放射治疗的补充，外束放射治疗（EBRT）的必要性尚不清楚。我们报告了随机接受两种不同补充 EBRT 方案的高风险特征患者的近距离放射治疗结果。
在 1999 年 12 月至 2004 年 6 月期间，247 名患者被随机分为 20 Gy 与 44 Gy 的 EBRT 后行钯-103 加量（115 Gy 与 90 Gy）。入选标准包括临床局限于器官的疾病，Gleason 评分 7-10 分和/或治疗前前列腺特异性抗原（PSA）水平 10-20ng/mL。中位随访时间为 9.0 年。生化无进展生存期（bPFS）定义为 PSA 水平在最低点后降至≤0.40ng/mL。中位治疗当天 90%目标体积的处方剂量为 125.7%；80 名男性接受雄激素剥夺治疗（中位 4 个月）。评估了多个参数对 bPFS 的影响。
对于整个队列，8 年时的特定原因生存率、bPFS 和总生存率分别为 97.7%、93.2%和 80.8%，10 年时分别为 96.9%、93.2%和 75.4%。20 Gy 和 44 Gy 组的 bPFS 率分别为 93.1%和 93.4%（p=0.994）。然而，在特定原因生存率或总生存率方面未发现统计学上的显著差异。按 PSA 水平≤10ng/mL 与>10ng/mL、Gleason 评分或雄激素剥夺治疗分层时，两种 EBRT 方案之间 bPFS 无统计学差异。多因素分析显示，bPFS 与植入前 PSA 和临床分期最密切相关。对于生化控制疾病的患者，中位 PSA 水平<0.02ng/mL。
本试验结果强烈表明，两种明显不同的补充 EBRT 方案可导致相似的特定原因生存率、bPFS 和总生存率。补充高剂量 EBRT 无获益可能是由于高质量的近距离放射治疗剂量分布。
