Bąk B, Kaczmarek K, Radoła D, Winiecki T, Bajon T
Department of Electroradiology, University of Medical Sciences, Poznań, Poland; Radiotherapy Department II, Greater Poland Cancer Center, Poznań, Poland.
Department of Electroradiology, University of Medical Sciences, Poznań, Poland.
Radiography (Lond). 2025 Aug;31(5):103016. doi: 10.1016/j.radi.2025.103016. Epub 2025 Jul 7.
Prostate cancer radiotherapy requires consistent bladder filling to optimize dose delivery and minimize toxicity. This prospective study evaluated the accuracy of ultrasound (US) in bladder volume assessment compared to Cone Beam Computed Tomography (CBCT).
22 prostate cancer patients treated with a total dose of 50 Gy in 2 Gy fractions (25 fractions) between August and December 2019 using volumetric arc therapy (VMAT). Prior to initial CT (iCT) scans and during radiotherapy patients consumed 600-800 ml (3-4 cups) of water. Daily ultrasound measurements were taken to determine the mean bladder volume (USGRT) before Cone Beam Computed Tomography (CBCT) imaging, where the radiation therapist contoured the bladder on CBCT scans, calculating bladder volume with a 2 mm margin.
A total of 1650 ultrasound measurements were performed. Statistical analysis included the Wilcoxon rank test and Spearman correlation to compare bladder volumes. The mean bladder volume measured by the US was 286 ml (SD ± 118), while CBCT recorded 241 ml (SD ± 124), with a strong correlation (r = 0.888, p < 0.001). The coefficient between USGRT and V2CBCT was r = 0.84 (p < 0.0001), indicating a significant correlation.
The Echoson® bladder scanner showed potential as a non-invasive alternative for daily bladder volume monitoring, reducing radiation exposure and streamlining treatment workflows. The bladder filling protocol is suitable for all patients, with a clinically acceptable measurement error of 17 %.
Ultrasound enhances daily IGRT verification while minimizing radiation dose from CBCT.
前列腺癌放疗需要膀胱持续充盈，以优化剂量输送并将毒性降至最低。本前瞻性研究评估了超声（US）与锥形束计算机断层扫描（CBCT）相比在膀胱容积评估中的准确性。
2019年8月至12月期间，22例前列腺癌患者接受了总量为50 Gy、每次2 Gy（共25次）的容积弧形调强放疗（VMAT）。在初始CT（iCT）扫描前及放疗期间，患者饮用600 - 800毫升（3 - 4杯）水。在锥形束计算机断层扫描（CBCT）成像前，每天进行超声测量以确定平均膀胱容积（USGRT），放疗技师在CBCT扫描上勾勒出膀胱轮廓，并计算出边缘为2毫米的膀胱容积。
共进行了1650次超声测量。统计分析包括Wilcoxon秩和检验和Spearman相关性分析，以比较膀胱容积。超声测量的平均膀胱容积为286毫升（标准差±118），而CBCT记录的为241毫升（标准差±124），两者具有强相关性（r = 0.888，p < 0.001）。USGRT与V2CBCT之间的系数为r = 0.84（p < 0.0001），表明存在显著相关性。
Echoson®膀胱扫描仪显示出作为日常膀胱容积监测的非侵入性替代方法的潜力，可减少辐射暴露并简化治疗流程。膀胱充盈方案适用于所有患者，临床可接受的测量误差为17%。
超声可增强每日图像引导放疗（IGRT）验证，同时将CBCT的辐射剂量降至最低。
