Department of Radiation Oncology, European Institute of Oncology, IRCCS, Milan, Italy.
Department of Radiation Oncology, European Institute of Oncology, IRCCS, Milan, Italy.
Int J Radiat Oncol Biol Phys. 2019 Nov 15;105(4):735-744. doi: 10.1016/j.ijrobp.2019.07.027. Epub 2019 Aug 1.
To compare clinical outcomes and toxicities of 2 radiation therapy (RT) schemes for localized prostate cancer (PCa): extreme hypofractionation (EH; fractions of 6.5-7 Gy to a total dose of 32.5-35 Gy) and the moderate hypofractionation (MH; 26 fractions of 2.7 Gy to a total dose of 70.2 Gy). A propensity score method was used to compare the EH-RT and MH-RT groups.
Our analysis included a total of 421 patients divided in 2 groups: 227 treated with MH-RT and 194 treated with EH-RT (43 and 30 months median follow-up, respectively). Propensity matching created comparable cohorts. Statistical evaluations were performed on the whole cohort, stratifying the analyses by risk strata factors identified with the propensity scores, and on a subgroup of patients matched by propensity score. Multivariate proportional hazard Cox models were used to compare the 2 groups, mainly for gastrointestinal and genitourinary toxicity and secondarily for clinical progression-free survival, biochemical progression-free survival, and overall survival.
Considering the whole population, acute genitourinary and gastrointestinal greater than grade 1 was significantly more frequent in the whole MH-RT group (P < .001 and P < .002, respectively). A borderline significantly greater late genitourinary was confirmed with the multivariate analysis (P = .07). Concerning tumor outcome, no statistically significant differences were observed. After propensity score matching, 226 patients were included in the analysis. The 2 obtained propensity score matched groups did not differ for any of the clinical and pathologic variables considered for the analysis, resulting in well-balanced cohorts. The results obtained on the whole population were confirmed in the matched groups.
EH-RT yields a decreased risk of acute or late toxicities compared with MH-RT, and oncologic outcomes were comparable. Our data indicate that EH-RT might be considered as a treatment modality of choice for select patients with PCa.
比较局部前列腺癌（PCa）两种放射治疗（RT）方案的临床结果和毒性：极度适形分割（EH；每次 6.5-7Gy，总剂量 32.5-35Gy）和中度适形分割（MH；26 次 2.7Gy，总剂量 70.2Gy）。采用倾向评分法比较 EH-RT 和 MH-RT 组。
我们的分析共纳入 421 例患者，分为 2 组：227 例接受 MH-RT 治疗，194 例接受 EH-RT 治疗（中位随访分别为 43 和 30 个月）。倾向评分匹配创建了可比队列。对整个队列进行统计学评估，按倾向评分确定的风险分层因素对分析进行分层，并对按倾向评分匹配的亚组患者进行分析。采用多变量比例风险 Cox 模型比较两组，主要比较胃肠道和泌尿生殖系统毒性，其次比较临床无进展生存率、生化无进展生存率和总生存率。
考虑到整个人群，整个 MH-RT 组急性泌尿生殖系统和胃肠道大于 1 级的发生率明显更高（P<0.001 和 P<0.002）。多变量分析显示，晚期泌尿生殖系统的发生率也有显著增加（P=0.07）。关于肿瘤结局，未观察到统计学差异。经过倾向评分匹配，有 226 例患者纳入分析。通过倾向评分匹配获得的两组在分析中考虑的所有临床和病理变量方面没有差异，结果得到了均衡的队列。在匹配组中也证实了在整个人群中获得的结果。
EH-RT 与 MH-RT 相比，急性或晚期毒性的风险降低，肿瘤学结果相当。我们的数据表明，EH-RT 可能被认为是选择前列腺癌患者的一种治疗方法。
