Division of Radiation Oncology, Far Eastern Memorial Hospital, New Taipei City, Taiwan.
Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei.
Technol Cancer Res Treat. 2021 Jan-Dec;20:1533033821995277. doi: 10.1177/1533033821995277.
Approximately 5%-10% of men who receive prostate cancer radiotherapy will suffer from radiation cystitis. Bladder filling before the administration of radiotherapy results in lower radiation exposure to the bladder. BladderScan, an ultrasound-based bladder volume scanner, has the potential to evaluate bladder volume during radiotherapy; thus, a prospective pilot study was initiated.
Eleven men receiving tomotherapy for localized prostate cancer were enrolled. The validity of BladderScan was evaluated by comparing the measurements from BladderScan with the calculated volume from megavoltage computed tomography (MVCT). With a crossover design to compare different methods in bladder filling, the radiotherapy was divided into 2 sequences. Conventional method: the patient was asked to drink water after voiding urine. The amount of water and the duration of waiting were the same as in the setting of the simulation. BladderScan feedback method: the bladder filling procedure depended on the BladderScan measurements.
There were 314 sets of data from 11 patients. The correlation coefficient between V and V was 0.87, where V is the mean volume of 3 measurements by BladderScan and V is the bladder volume derived from MVCT. The BladderScan feedback method resulted in a significant larger bladder volume than the conventional method, with a mean difference of 36.9 mL. When the failure was defined as V <80% of planned volume, the BladderScan feedback method brought about a relative reduction in the failure rate with an odds ratio of 0.44 and an absolute reduction of 9.1%.
The accuracy of BladderScan was validated by MVCT in our study. The BladderScan feedback method can help patients fill the bladder adequately, with a larger bladder volume and a lower failure rate.
约 5%-10%接受前列腺癌放射治疗的男性会出现放射性膀胱炎。放射治疗前充盈膀胱可降低膀胱的放射暴露。膀胱扫描（一种基于超声的膀胱容量扫描仪）有可能在放射治疗期间评估膀胱容量；因此，开展了一项前瞻性试点研究。
入组 11 例接受适形调强放疗的局限性前列腺癌患者。通过将膀胱扫描的测量值与兆伏 CT（MVCT）计算的体积进行比较，评估膀胱扫描的准确性。采用交叉设计比较不同膀胱充盈方法，将放射治疗分为 2 个序列。常规方法：患者在排空尿液后饮水。喝水的量和等待的时间与模拟时相同。膀胱扫描反馈方法：膀胱充盈过程取决于膀胱扫描的测量值。
11 例患者共有 314 组数据。V 和 V 之间的相关系数为 0.87，其中 V 为膀胱扫描 3 次测量的平均体积，V 为 MVCT 得出的膀胱体积。与常规方法相比，膀胱扫描反馈方法导致膀胱容量显著增大，平均差异为 36.9mL。当将 V <80%计划体积定义为失败时，膀胱扫描反馈方法可使失败率相对降低，优势比为 0.44，绝对降低 9.1%。
本研究通过 MVCT 验证了膀胱扫描的准确性。膀胱扫描反馈方法可帮助患者充分充盈膀胱，增加膀胱容量，降低失败率。
