Related Experiment Video
Updated: May 12, 2026
Proton Therapy Delivery and Its Clinical Application in Select Solid Tumor Malignancies
Published on: February 6, 2019
Upper rectal fixation with an endorectal balloon in prostate cancer radiotherapy
1Department of Radiation Oncology, Tokyo-Edogawa Cancer Centre, Edogawa Hospital.
Purpose:
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.
Materials:
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.
Results:
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).
Conclusion:
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.
