Effect of pelvic irradiation on gastrointestinal function: a prospective longitudinal study

Area of Science:

• Gastroenterology
• Radiation Oncology
• Oncology

Background:

• Radiation enteritis is a known complication of therapeutic irradiation.
• The specific effects of abdominal and/or pelvic irradiation on gastrointestinal function are not well understood.
• Treatments for radiation-induced gastrointestinal dysfunction are often unsuccessful.

Purpose of the Study:

• To prospectively evaluate the short- and long-term effects of therapeutic irradiation on gastrointestinal function.
• To define the impact of abdominal and/or pelvic irradiation on digestive processes.

Main Methods:

• A prospective study involving 27 patients undergoing radiation therapy for malignant disease.
• Evaluation of gastrointestinal symptoms, absorption (bile acid, vitamin B12, lactose, fat), gastric emptying, intestinal transit, stool weight, and intestinal permeability.
• Measurements were taken before, during, and at multiple time points after radiation therapy, with comparisons to 18 healthy volunteers.

Main Results:

• Radiation therapy increased stool frequency, decreased bile acid and vitamin B12 absorption, increased fecal fat excretion, and accelerated small-intestinal and whole-gut transit.
• While some functions improved over time, significant abnormalities persisted 1-2 years post-irradiation in 16 of 18 patients.
• Combined abdominal and pelvic irradiation led to greater stool weight and faster whole-gut transit compared to pelvic irradiation alone. Prior surgery exacerbated stool frequency and fecal fat excretion.

Conclusions:

• Pelvic irradiation results in widespread and persistent gastrointestinal functional changes.
• Understanding these long-term effects is crucial for managing patients treated with radiation therapy.
• Further research may be needed to develop more effective interventions for radiation enteritis.