Hama Yukihiro, Tate Etsuko
Department of Radiation Oncology, Tokyo-Edogawa Cancer Centre, Edogawa Hospital.
J Radiosurg SBRT. 2024;9(2):129-133.
Despite the efficacy of endorectal balloon (ERB) in reducing rectal radiation dose, the effectiveness of upper rectal fixation remains to be evaluated. The purpose of this study was to evaluate the impact of ERB on upper rectal fixation in patients diagnosed with localized prostate cancer.
Cine MRI was performed in 46 patients with localized prostate cancer to assess the stability of the anterior rectal wall with and without ERB by calculating the standard deviation of the normalized signal intensity at the level of the midgland or the seminal vesicle.
The standard deviation of the normalized signal intensity for the anterior rectal wall decreased significantly with the use of ERB both at the level of the midgland (p < 0.05) and the seminal vesicle (p < 0.05). The standard deviation of the anterior rectal wall at the level of the seminal vesicle was significantly higher than at the level of the midgland without ERB (p < 0.05). But with ERB, the standard deviation of the normalized signal intensity at the level of the seminal vesicle became comparable to that at the level of the midgland (p = 0.392).
The anterior rectal wall is stabilized by ERBs not only at the level of the midgland but also at the level of the seminal vesicle. ERBs can transform the rectum from a moving and deformable organ into a static and rigid organ.
尽管直肠内气囊（ERB）在降低直肠辐射剂量方面具有疗效，但直肠上段固定的有效性仍有待评估。本研究的目的是评估ERB对诊断为局限性前列腺癌患者直肠上段固定的影响。
对46例局限性前列腺癌患者进行电影磁共振成像（Cine MRI），通过计算腺体中部或精囊水平归一化信号强度的标准差，评估有无ERB时直肠前壁的稳定性。
使用ERB时，腺体中部（p < 0.05）和精囊水平（p < 0.05）直肠前壁归一化信号强度的标准差均显著降低。在无ERB时，精囊水平直肠前壁的标准差显著高于腺体中部水平（p < 0.05）。但使用ERB时，精囊水平归一化信号强度的标准差与腺体中部水平相当（p = 0.392）。
ERB不仅能在腺体中部水平，也能在精囊水平稳定直肠前壁。ERB可将直肠从一个可移动和变形的器官转变为一个静态和刚性的器官。
