title: Influence of antiflatulent dietary advice on intrafraction motion for prostate cancer radiotherapy.
abstract: OBJECTIVE
  To evaluate the effect of an antiflatulent dietary advice on the intrafraction prostate motion in patients treated with intensity-modulated radiotherapy (IMRT) for prostate cancer.
  
  
  METHODS
  Between February 2002 and December 2009, 977 patients received five-beam IMRT for prostate cancer to a dose of 76 Gy in 35 fractions combined with fiducial markers for position verification. In July 2008, the diet, consisting of dietary guidelines to obtain regular bowel movements and to reduce intestinal gas by avoiding certain foods and air swallowing, was introduced to reduce the prostate motion. The intrafraction prostate movement was determined from the portal images of the first segment of all five beams. Clinically relevant intrafraction motion was defined as ≥50% of the fractions with an intrafraction motion outside a range of 3 mm.
  
  
  RESULTS
  A total of 739 patients were treated without the diet and 105 patients were treated with radiotherapy after introduction of the diet. The median and interquartile range of the average intrafraction motion per patient was 2.53 mm (interquartile range, 2.2-3.0) without the diet and 3.00 mm (interquartile range, 2.4-3.5) with the diet (p < .0001). The percentage of patients with clinically relevant intrafraction motion increased statistically significant from 19.1% without diet to 42.9% with a diet (odds ratio, 3.18; 95% confidence interval, 2.07-4.88; p < .0001).
  
  
  CONCLUSIONS
  The results of the present study suggest that antiflatulent dietary advice for patients undergoing IMRT for prostate cancer does not reduce the intrafraction movement of the prostate. Therefore, antiflatulent dietary advice is not recommended in clinical practice for this purpose.
authors.affiliation: Department of Radiation Oncology, University Medical Center Utrecht, Utrecht, The Netherlands. I.M.Lips@umcutrecht.nl
authors.forename: Irene M
authors.initials: IM
authors.lastname: Lips
authors.forename: Alexis N T J
authors.initials: AN
authors.lastname: Kotte
authors.forename: Carla H
authors.initials: CH
authors.lastname: van Gils
authors.forename: Monique E
authors.initials: ME
authors.lastname: van Leerdam
authors.forename: Uulke A
authors.initials: UA
authors.lastname: van der Heide
authors.forename: Marco
authors.initials: M
authors.lastname: van Vulpen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016001:Confidence Intervals; D004032:Diet / Q000009:adverse effects; D019583:Dose Fractionation, Radiation; D057918:Fiducial Markers; D005414:Flatulence / Q000178:diet therapy* / Q000517:prevention & control; D006801:Humans; D008297:Male; D008875:Middle Aged; D009068:Movement; D016017:Odds Ratio; D011467:Prostate / Q000000981:diagnostic imaging*; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D011859:Radiography; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D017211:Treatment Failure