Nutritional strategies to prevent gastrointestinal toxicity during pelvic radiotherapy.

Radiotherapy-induced damage to non-cancerous gastrointestinal mucosa has effects on secretory and absorptive functions and can interfere with normal gastrointestinal physiology. Nutrient absorption and digestion may be compromised. Dietary manipulation is an attractive option with sound rationale for intervention. The aim of this review was to synthesise published evidence for the use of elemental formulae, low or modified fat diets, fibre, lactose restriction and probiotics, prebiotics and synbiotics to protect the bowel from gastrointestinal side effects during long-course, radical pelvic radiotherapy. Thirty original studies (recruiting n 3197 patients) were identified comprising twenty-four randomised controlled trials, four cohort studies and two comparator trials. Endpoints varied and included symptom scales (Inflammatory Bowel Disease Questionnaire, Common Technology Criteria for Adverse Events, Radiation Therapy Oncology Group) and Bristol Stool Scale. Dietary and supplement interventions were employed with many studies using a combination of interventions. Evidence from RCT was weak for elemental, low or modified fat and low-lactose interventions and modestly positive for the manipulation of fibre during radiotherapy. Evidence for probiotics as prophylactic interventional agents was more promising with a number of trials reporting positive results but strength and strains of interventions vary, as do methodologies and endpoints making it difficult to arrive at firm conclusions with several studies lacking statistical power. This consolidated review concludes that there is insufficient high-grade evidence to recommend nutritional intervention during pelvic radiotherapy. Total replacement of diet with elemental formula could be effective in severe toxicity but this is unproven. Probiotics offer promise but cannot be introduced into clinical practice without rigorous safety analysis, not least in immunocompromised patients.

Evaluating the efficacy of statins and ACE-inhibitors in reducing gastrointestinal toxicity in patients receiving radiotherapy for pelvic malignancies.

INTRODUCTION: 3-Hydroxy-methylglutaryl coenzyme-a reductase inhibitors (statins) improve survival following pelvic irradiation for cancer. Large studies suggest that patients with hypertension may have reduced gastrointestinal (GI) toxicity. Animal data suggest that statins and ACE inhibitors (ACEi) may protect against normal tissue injury. Their efficacy in humans has not been reported. AIMS/METHODS: To evaluate the impact of statins and ACEi on normal tissue toxicity during radical pelvic radiotherapy. GI symptomatology was recorded prospectively before radiotherapy, weekly during treatment and 1 year later using the inflammatory bowel disease questionnaire-bowel (IBDQ-B) subset. Cumulative acute toxicity (IBDQ-B AUC) and worst score were determined. Dose, brand and duration of statin and/or ACEi usage were obtained from General Practitioners. RESULTS: Of 308 patients recruited, 237 had evaluable acute drug and toxicity data and 164 had data at 1year. Acutely, 38 patients (16%) were taking statins, 39 patients (16.5%) were taking ACEi and 18 patients (7.6%) were taking statin+ACEi. Mean changes in acute scores were 7.3 points (non-statin users), 7.3 (non-ACEi users) and 7.0 (non-statin+ACEi users) compared to 4.8 points (statin users), 5.0 points (ACEi users) and 4.9 points (statin+ACEi users). Statin use (p=0.04) and combined statin+ACEi use (p=0.008) were associated with reduced acute IBDQ-B AUC after controlling for baseline scores (ANOVA). At 1 year, users maintained higher IBDQ-B scores than non-users in all user subgroups. CONCLUSION: Use of statin or statin+ACEi medication during radical pelvic radiotherapy significantly reduces acute gastrointestinal symptoms scores and also appears to provide longer-term sustained protection.

Predicting late effects of pelvic radiotherapy: is there a better approach?

PURPOSE: Significant chronic symptoms following pelvic radiotherapy occur more frequently than commonly realized. Predictive factors for the development of late symptoms are poorly defined. Moderate sustained acute (cumulative) toxicity might predict severe late effects better than peak reaction. METHODS AND MATERIALS: To determine prospectively whether peak or cumulative gastrointestinal (GI) acute symptoms better predict late symptoms in patients receiving pelvic radiotherapy. Symptom scores were measured weekly from the start of radiotherapy, and at 1 year using the Modified Inflammatory Bowel Disease Questionnaire-Bowel subset. The possible prognostic impact of patient-related factors was explored. RESULTS: Three hundred and eight patients were recruited. 100 were excluded due to lack of follow-up data at one year resulting from death, too ill, stoma, relapsed, non-response or withdrawal. A further 15 were excluded for incomplete data, leaving 193 patients with evaluable data. Of these, 28 had GI, 101 urological, and 64 gynecological cancers. Patients' median age was 65 years (range, 23-82), and they were treated with median 60 Gy dose for a median of 6 weeks. Univariate analysis revealed a significant association between cumulative acute symptom scores and scores at 1 year (p < 0.001), which was dose-independent (p < 0.001). Acute peak and 1-year scores were not associated (p = 0.431). The correlation coefficient between cumulative acute symptoms and symptoms at 1 year was 0.367 and for peak acute symptoms was weaker at 0.057. Patients with an abnormal body mass index and current smokers were more likely to experience worse symptoms at 1 year. CONCLUSION: Cumulative acute symptoms are more predictive of late symptoms than peak acute changes in score. This association is independent of the radiotherapy dose delivered and is suggestive of a consequential late effect.