Department of Radiation Therapy, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada; Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada.
Department of Radiation Therapy, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.
Pract Radiat Oncol. 2018 Mar-Apr;8(2):116-122. doi: 10.1016/j.prro.2017.10.012. Epub 2017 Nov 4.
Radiation therapy is a standard treatment option for prostate cancer. With growing use of escalated doses and tighter margins, procedures to limit rectal size variation are needed to reduce prostate motion, increase treatment accuracy, and minimize rectal toxicity. This prospective study was done to determine whether the introduction of an antiflatulent medication would decrease rectal distention at computed tomography (CT) simulation and throughout a course of radiation therapy.
Patients undergoing a radical course of radiation therapy to the prostate/prostate bed were eligible to participate. Participants were randomly assigned to the intervention arm (antiflatulent medication) or the control arm (no medication). For each participant, the number of CT simulation rescans was recorded. Rectal diameters were measured on CT simulation and treatment cone beam CT scans. Acute rectal toxicities were assessed at baseline and weekly using National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE), version 4.0. A χ analysis was used to compare the number of participants requiring a rescan in each study arm. Change in rectal diameter over time was assessed using repeated measures analysis of variance.
A total of 78 patients participated, with equal numbers assigned to each study arm. There was no significant difference between arms in the number of participants requiring a CT simulation rescan (P = .5551). There was no significant variation in rectal diameter between arms (P = .8999); however, there was a significant effect of time (P = .0017) and a significant interaction effect between study arm and time on rectal diameter (P = .0141). No acute rectal toxicities above grade 2 were reported.
The addition of antiflatulent medication did not affect the frequency of CT simulation rescans. Both time and the interaction between study arm and time had a statistically significant effect on rectal diameter, although neither finding was clinically significant. Instead, standardized bowel preparation education developed for this study may have been sufficient to limit rectal size variation.
放射治疗是前列腺癌的标准治疗选择。随着递增剂量和更紧的边缘的广泛应用，需要采取限制直肠大小变化的措施来减少前列腺运动，提高治疗准确性并最大限度地减少直肠毒性。本前瞻性研究旨在确定引入抗胀气药物是否会减少 CT 模拟和放射治疗过程中的直肠扩张。
接受根治性前列腺/前列腺床放射治疗的患者有资格参加。参与者被随机分配到干预组（抗胀气药物）或对照组（无药物）。对于每个参与者，记录了 CT 模拟重扫的次数。在 CT 模拟和治疗锥形束 CT 扫描上测量直肠直径。使用国家癌症研究所常见不良事件术语标准（NCI CTCAE）第 4.0 版在基线和每周评估急性直肠毒性。使用 χ 分析比较每个研究臂中需要重扫的参与者人数。使用重复测量方差分析评估直肠直径随时间的变化。
共有 78 名患者参加，每个研究臂的人数相等。在需要 CT 模拟重扫的参与者人数方面，两组之间没有显著差异（P =.5551）。两组之间直肠直径没有显著差异（P =.8999）；然而，时间有显著影响（P =.0017），研究臂和时间对直肠直径的交互作用也有显著影响（P =.0141）。没有报告 2 级以上的急性直肠毒性。
添加抗胀气药物不会影响 CT 模拟重扫的频率。时间和研究臂与时间之间的相互作用对直肠直径都有统计学上的显著影响，尽管这两种发现都没有临床意义。相反，为这项研究制定的标准化肠道准备教育可能足以限制直肠大小的变化。
