title: Hydrogel injection reduces rectal toxicity after radiotherapy for localized prostate cancer.
abstract: OBJECTIVE
  Injection of a hydrogel spacer before prostate cancer radiotherapy (RT) is known to reduce the dose to the rectal wall. Clinical results from the patient's perspective are needed to better assess a possible benefit.
  
  
  METHODS
  A group of 167 consecutive patients who received prostate RT during the years 2010 to 2013 with 2‑Gy fractions up to 76 Gy (without hydrogel, n = 66) or 76-80 Gy (with hydrogel, n = 101) were included. The numbers of interventions resulting from bowel problems during the first 2 years after RT were compared. Patients were surveyed prospectively before RT, at the last day of RT, and at a median of 2 and 17 months after RT using a validated questionnaire (Expanded Prostate Cancer Index Composite).
  
  
  RESULTS
  Baseline patient characteristics were well balanced. Treatment for bowel symptoms (0 vs. 11 %; p < 0.01) and endoscopic examinations (3 vs. 19 %; p < 0.01) were performed less frequently with a spacer. Mean bowel function scores did not change for patients with a spacer in contrast to patients without a spacer (mean decrease of 5 points) >1 year after RT in comparison to baseline, with 0 vs. 12 % reporting a new moderate/big problem with passing stools (p < 0.01). Statistically significant differences were found for the items "loose stools", "bloody stools", "painful bowel movements" and "frequency of bowel movements".
  
  
  CONCLUSIONS
  Spacer injection is associated with a significant benefit for patients after prostate cancer RT.
authors.affiliation: Department of Radiation Oncology, RWTH Aachen University, Pauwelsstraße 30, 52057, Aachen, Deutschland. MPinkawa@ukaachen.de.
authors.forename: Michael
authors.identifier: http://orcid.org/0000-0002-6450-297X
authors.initials: M
authors.lastname: Pinkawa
authors.affiliation: Department of Radiation Oncology, RWTH Aachen University, Pauwelsstraße 30, 52057, Aachen, Deutschland.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Berneking
authors.affiliation: Department of Radiation Oncology, RWTH Aachen University, Pauwelsstraße 30, 52057, Aachen, Deutschland.
authors.forename: Liane
authors.initials: L
authors.lastname: König
authors.affiliation: Department of Radiation Oncology, RWTH Aachen University, Pauwelsstraße 30, 52057, Aachen, Deutschland.
authors.forename: Dilini
authors.initials: D
authors.lastname: Frank
authors.affiliation: Department of Radiation Oncology, RWTH Aachen University, Pauwelsstraße 30, 52057, Aachen, Deutschland.
authors.forename: Marilou
authors.initials: M
authors.lastname: Bretgeld
authors.affiliation: Department of Radiation Oncology, RWTH Aachen University, Pauwelsstraße 30, 52057, Aachen, Deutschland.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Eble
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D006801:Humans; D020100:Hydrogels / Q000008:administration & dosage*; D007267:Injections; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000150:complications / Q000175:diagnosis / Q000532:radiotherapy*; D011832:Radiation Injuries / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control*; D011835:Radiation Protection / Q000379:methods*; D011879:Radiotherapy Dosage; D012002:Rectal Diseases / Q000175:diagnosis / Q000209:etiology* / Q000517:prevention & control*; D016896:Treatment Outcome
chemical_list: D020100:Hydrogels
keywords: Prostate neoplasm; Quality of life; Questionnaires; Radiotherapy, image-guided; Radiotherapy, intensity-modulated; Spacer