Anal and rectal function after intensity-modulated prostate radiotherapy with endorectal balloon

Area of Science:

• Oncology
• Radiation Therapy
• Gastroenterology

Background:

• Late anorectal toxicity is a significant concern impacting quality of life for prostate cancer patients undergoing external beam radiotherapy (EBRT).
• An endorectal balloon (ERB) is used during EBRT to potentially mitigate anorectal toxicity.
• Intensity-modulated radiotherapy (IMRT) with ERB is a technique aimed at improving outcomes.

Purpose of the Study:

• To objectively assess changes in anorectal function over time following prostate IMRT with an ERB.
• To quantify the impact of IMRT with ERB on rectal distensibility and sensory perception.

Main Methods:

• Sixty men receiving IMRT with ERB for prostate cancer were evaluated.
• Barostat measurements and anorectal manometry were performed before and at 6 months, 1 year, and 2 years post-radiotherapy.
• Primary outcomes included rectal distensibility, rectal sensory thresholds, and anal pressures.

Main Results:

• After 2 years, maximal rectal capacity decreased significantly (p < 0.001) and rectal sensory thresholds increased (p < 0.01).
• Anal maximum pressure also diminished post-IMRT (p = 0.006).
• While rectal compliance was not significantly changed, other functional parameters showed alterations.

Conclusions:

• Prostate radiotherapy, even with IMRT and ERB, can lead to progressive reductions in rectal capacity and sensory function over time.
• These findings suggest that while IMRT with ERB may offer benefits compared to conventional techniques, long-term anorectal function requires careful monitoring.