Original Research Acute Nutritional and Intestinal Changes after Pelvic Radiation M. Pı ´a de la Maza, MD, MSc, Martı ´n Gotteland, PhD, Claudia Ramı ´rez, Magdalena Araya, MD, PhD, Talı ´a Yudin, MD, Daniel Bunout, MD, and Sandra Hirsch, MD, MSc Institute of Nutrition and Food Technology (INTA), University of Chile (M.P.M., M.G., C.R., M.A., D.B., S.H.), Arturo Lo ´pez Pe ´rez Foundation (T.Y.), Santiago, CHILE Key words: radiotherapy, actinic enteritis, pelvic radiation, intestinal permeability 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 and 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 perme- ability 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. INTRODUCTION Radiation therapy plays a fundamental role in malignancy treatment; however, it has clinical limitations due to its adverse effects, mainly damage to critical normal tissues. One of the most serious complications of abdominal or pelvic radiotherapy is actinic damage to the bowel, leading to nausea, vomiting, diarrhea and abdominal cramps during or shortly after therapy [1]. These usually last for a few weeks after treatment and then disappear [2,3,4], but up to 61% of patients develop persistent diarrhea or increased frequency of bowel movements, typical of chronic radiation enteritis [4]. Prognosis of this chronic condi- tion is adverse because morbidity and mortality of surgical interventions for complications of chronic radiation enteritis are high [5]. Descriptions of acute radiation damage are mostly retrospective, include both abdominal and pelvic radiation and do not evaluate nutritional variables, which may concur to chronic complications. The terminal ileum, sigmoid colon and rectum are the sites most frequently damaged by pelvic radiation, while jejunum and proximal ileum are seldom involved; nevertheless, mortal- ity of radiation enteritis is fourfold higher than colonic lesions [6]. Whether significant tissue injury occurs in organs distant to the radiation field is still controversial [1,18]. In humans, acute histologic changes shortly after radiation consist of reduction of crypt mitoses, villous shortening, plasma cell infiltration of the lamina propria, megalocytosis of epithelial cells and, less frequently, formation of microabsceses of the crypts, all which are potentially reversible [1]. Both acceleration of intestinal transit time and decreased bile salts resorption at the terminal ileum play a role in the appearance of diarrhea [7,8,9,10]. Simultaneously, intestinal permeability to Address correspondence to: M. Pı ´a de la Maza MD, MSc, INTA, University of Chile, J.P. Alessandri 5540, Santiago, CHILE. E-mail: mpmaza@uec.inta.uchile.cl. Journal of the American College of Nutrition, Vol. 20, No. 6, 637–642 (2001) Published by the American College of Nutrition 637