Nishioka Kentaro, Gotoh Kento, Hashimoto Takayuki, Abe Takashige, Osawa Takahiro, Matsumoto Ryuji, Yokota Isao, Katoh Norio, Kinoshita Rumiko, Yasuda Koichi, Yakabe Toshiaki, Yoshimura Takaaki, Takao Seishin, Shinohara Nobuo, Aoyama Hidefumi, Shimizu Shinichi, Shirato Hiroki
Department of Radiation Medical Science and Engineering, Faculty of Medicine, Hokkaido University, Sapporo, Hokkaido, Japan.
Department of Radiation Medical Science and Engineering, Radiation Medical physics, Hokkaido University, Sapporo, Hokkaido, Japan.
BJR Open. 2021 Nov 11;3(1):20210064. doi: 10.1259/bjro.20210064. eCollection 2021.
The purpose of this study is to investigate whether verbal instructions are sufficient for bladder volume (BV) control not to deteriorate prostate position reproducibility in image-guided spot scanning proton therapy (SSPT) for localized prostate cancer.
A total of 268 treatment sessions in 12 consecutive prostate cancer patients who were treated with image-guided SSPT with fiducial markers were retrospectively analyzed. In addition to strict rectal volume control procedures, simple verbal instructions to void urine one hour before the treatment were used here. The BV was measured by a Bladder Scan just before the treatment, and the prostate motion was measured by intraprostatic fiducial markers and two sets of X-ray fluoroscopy images. The correlation between the BV change and prostate motion was assessed by linear mixed-effects models and systematic and random errors according to the reproducibility of the BV.
The mean absolute BV change during treatment was from -98.7 to 86.3 ml (median 7.1 ml). The mean absolute prostate motion of the patients in the left-right direction was -1.46 to 1.85 mm; in the cranial-caudal direction it was -6.10 to 3.65 mm, and in the anteroposterior direction -1.90 to 5.23 mm. There was no significant relationship between the BV change and prostate motion during SSPT. The early and late genitourinary and gastrointestinal toxicity was minimal with a minimum follow up of 4.57 years.
Simple verbal instructions about urination was suggested to be sufficient to control the BV not to impact on the prostate motion and clinical outcomes in image-guided SSPT. Careful attention to BV change is still needed when the seminal vesicle is to be treated.
Our data demonstrated that there was no apparent relationship between BV changes and prostate position reproducibility and simple verbal instruction about urination could be sufficient for image-guided SSPT.
本研究旨在调查在局部前列腺癌的图像引导点扫描质子治疗（SSPT）中，口头指示是否足以控制膀胱容量（BV），以使前列腺位置的可重复性不致恶化。
回顾性分析了12例接受带基准标记的图像引导SSPT治疗的连续前列腺癌患者的268个治疗疗程。除了严格的直肠容量控制程序外，此处还采用了在治疗前1小时排尿的简单口头指示。在治疗前通过膀胱扫描仪测量BV，并通过前列腺内基准标记和两组X线透视图像测量前列腺运动。通过线性混合效应模型以及根据BV的可重复性评估系统误差和随机误差，评估BV变化与前列腺运动之间的相关性。
治疗期间BV的平均绝对变化为-98.7至86.3毫升（中位数为7.1毫升）。患者在左右方向上的平均绝对前列腺运动为-1.46至1.85毫米；在头脚方向上为-6.10至3.65毫米，在前后方向上为-1.90至5.23毫米。在SSPT期间，BV变化与前列腺运动之间无显著关系。在至少4.57年的随访中，早期和晚期泌尿生殖系统及胃肠道毒性极小。
建议关于排尿的简单口头指示足以控制BV，而不会影响图像引导SSPT中的前列腺运动和临床结果。在治疗精囊时，仍需要密切关注BV变化。
我们的数据表明，BV变化与前列腺位置可重复性之间没有明显关系，关于排尿的简单口头指示对于图像引导SSPT可能就足够了。
