Is rectal preparation necessary in contemporary image-guided prostate radiotherapy?

Area of Science:

• Radiation Oncology
• Medical Imaging
• Prostate Cancer Treatment

Background:

• Rectal preparation was standard in older prostate radiotherapy techniques.
• Its necessity in modern 3D image-guided radiotherapy (IGRT) is unclear.

Purpose of the Study:

• To evaluate the impact of omitting rectal preparation on prostate motion (inter- and intrafraction).
• To assess the influence of rectal volume on prostate motion during radiotherapy.
• To determine the necessity of rectal preparation in contemporary prostate IGRT.

Main Methods:

• Analysis of two patient datasets undergoing prostate radiotherapy.
• Dataset 1: Compared patients with and without rectal preparation, assessing interfraction motion using CBCT, stratified by rectal volume.
• Dataset 2: Assessed inter- and intrafraction motion in patients without rectal preparation, correlating rectal volume with motion.

Main Results:

• Rectal preparation slightly reduced the proportion of patients with large rectal volumes (≥90 cm³).
• A large rectal volume was associated with modest increases in interfraction prostate motion but did not affect intrafraction motion.
• No significant correlation was found between rectal volume during treatment and intrafraction motion.

Conclusions:

• Rectal preparation offers minimal reduction in large rectal volumes.
• Contemporary IGRT may not require universal rectal preparation for prostate cancer.
• Findings suggest a potential shift away from routine rectal preparation in specific patient groups.