Acute nutritional and intestinal changes after pelvic radiation

Objective: Pelvic radiotherapy induces acute small bowel injury but its effects on nutritional status are unknown. The objective of this study was to prospectively evaluate nutritional, functional and morphologic intestinal changes, after radiotherapy. Methods: Fifteen patients were studied before and after pelvic irradiation. A clinical. nutritional and routine clinical laboratory assessment was performed. Nutritional parameters included dietary recall, subjective global assessment, anthropometric measurements (body mass index, skinfold thickness at four sites and circumferences of arm, waist aod hip), hand grip strength, indirect calorimetry and Dual Energy X-ray absortiometry (DEXA). Intestinal parameters included permeabilty to sugars (assessed by lactulose and mannitol urinary excretion), intestinal transit time (measured by hydrogen breath test after ingestion of lactulose) and jejunal biopsies. Results: Thirteen patients presented diarrhea during radiation therapy. After five weeks, intestinal permeability increased, while intestinal transit time decreased. The second biopsy showed hypertrophy of villae and crypts. Simultaneously, patients lost weight at the expense of fat free mass. Resting energy expenditure was elevated prior to treatment and declined after five weeks. Changes in caloric ingestion were not significant. Conclusions: Our results indicate that pelvic radiation induces a loss of fat free mass along with intestinal morphologic and functional changes.