盆腔放疗可能会导致骨矿物质密度 (BMD) 降低和骨折风险增加，这对于同时接受雄激素剥夺治疗 (ADT) 的前列腺癌 (PCa) 患者来说尤其令人担忧。我们对一项随机、双盲、安慰剂对照试验进行了探索性分析，以确定既往接受盆腔外照射放疗 (XRT) 是否会影响接受 ADT 治疗的 PCa 患者的 BMD 和骨折风险。年龄 ≥ 的非转移性 PCa 患者70 岁或 <70 岁的低 BMD（T 分数 < -1）或骨质疏松性骨折，接受 ADT ≥12 个月，被随机分配接受每 6 个月接受一次 densoumab 与安慰剂，持续 3 年。在基线以及第 1、3、6、12、24 和 36 个月时测量 BMD。我们应用多变量线性混合效应模型，其中包含治疗臂与之前接受盆腔 XRT 暴露之间的交互项，以评估 XRT 对百分比的差异影响两个治疗组之间的 BMD 变化。在 1407 名符合条件的患者中，31% (n=447) 的患者之前接受过盆腔放疗。既往接受过骨盆放疗的患者（5.8%，447 名患者中的 26 名）或未接受过骨盆放疗（5.2%，960 名患者中的 50 名）的临床骨折情况没有差异（p=0.42）。接受既往骨盆 XRT 与安慰剂组 BMD 显着改善 0.54%（95% CI：0.05 至 1.02）相关，而安慰剂组 BMD 不显着下降 0.04%（95% CI：-0.47 至 0.35）。分别为狄诺塞麦臂。 （交互作用 p=0.007）。两个治疗组之间，骨盆放射治疗对腰椎 BMD 变化百分比 (p=0.65) 或全髋关节骨密度变化 (p=0.39) 的影响没有显着差异。我们没有发现足够的证据表明骨盆 XRT 对骨盆骨密度变化有任何不利影响。狄诺塞麦对 BMD 变化百分比的治疗效果，临床骨折发生率仅为 5% 左右。版权所有 © 2023。由 Elsevier Inc. 出版。

Pelvic radiotherapy may lead to decreased bone mineral density (BMD) and increased risk of fracture which could be of particular concern in prostate cancer (PCa) patients who also receive androgen deprivation therapy (ADT). We performed exploratory analysis of a randomized, double-blind, placebo-controlled trial to determine if exposure to prior pelvic external beam radiotherapy (XRT) affects BMD and risk of fracture in PCa patients treated with ADT.Non-metastatic PCa patients with age ≥70 years or <70 years with low BMD (T-score < -1) or osteoporotic fracture, on ADT for ≥12 months, were randomly assigned to receive densoumab versus placebo every 6 months for 3 years. BMD was measured at baseline, and at months 1, 3, 6, 12, 24, and 36. We applied multivariable linear mixed effect models with an interaction term between the treatment arm and exposure to prior pelvic XRT to evaluate differential XRT effect on percent BMD change between the two treatment arms.Among 1407 eligible patients, 31% (n=447) of patients received prior pelvic radiotherapy. There was no difference in any clinical fractures among patients with (5.8%, 26 out of 447) or without (5.2%, 50 out of 960) prior pelvic radiotherapy (p=0.42). Receipt of prior pelvic XRT was associated with a significant 0.54 percent improvement in BMD (95% CI: 0.05 to 1.02) in the placebo group and a non-significant 0.04 percent decline in BMD (95% CI: -0.47 to 0.35) in the denosumab arm, respectively. (interaction p=0.007). There was no significant difference in pelvic radiotherapy effect on percent BMD change in lumbar spine (p=0.65) or total hip (p=0.39) between the two treatment groups.We did not find sufficient evidence to suggest any detrimental impact of pelvic XRT on the treatment effect from denosumab on percent BMD change with only about 5% incidence of clinical fractures.Copyright © 2023. Published by Elsevier Inc.