Morphologic change of rectosigmoid colon using belly board and distended bladder protocol

Area of Science:

• Oncology
• Radiation Oncology
• Surgical Oncology

Background:

• Rectal cancer treatment often involves preoperative radiotherapy.
• Accurate radiation targeting is crucial to minimize side effects and preserve organs at risk.
• The rectosigmoid colon's mobility can complicate radiation planning.

Purpose of the Study:

• To investigate morphologic changes of the rectosigmoid colon using a belly board and distended bladder.
• To evaluate the potential for excluding the proximal anastomosis margin from the radiation field.
• To assess the impact of this positioning technique on radiation planning parameters.

Main Methods:

• Comparison of two patient groups: standard prone position (Group A) vs. belly board with distended bladder (Group B).
• Simulation using planning computed tomography (CT) scans to delineate the rectosigmoid colon.
• Assessment of rectosigmoid colon volume and redundancy within the radiation field.

Main Results:

• Group B demonstrated significantly straighter rectosigmoid colons with reduced redundancy (42% vs. 10%).
• The mean irradiated rectosigmoid colon volume was significantly smaller in Group B (49.1 mL vs. 56.7 mL).
• A strong correlation was found between bladder volume and in-field rectosigmoid colon volume (R = 0.86).

Conclusions:

• The belly board and distended bladder protocol effectively straightens the rectosigmoid colon.
• This technique facilitates the exclusion of the proximal margin of anastomosis from the radiation field.
• Improved radiation targeting may lead to better outcomes in rectal cancer patients.