title: Development of late toxicity and International Prostate Symptom Score resolution after external-beam radiotherapy combined with pulsed dose rate brachytherapy for prostate cancer.
abstract: OBJECTIVE
  To investigate the development of gastrointestinal (GI) toxicity, genitourinary (GU) toxicity, erectile dysfunction, and International Prostate Symptom Score (IPSS) resolution in a cohort of patients treated with external-beam radiotherapy (EBRT) followed by a brachytherapy pulsed dose rate (PDR) boost.
  
  
  METHODS
  Between 2002 and 2008, 110 patients were treated with 46-Gy EBRT followed by PDR brachytherapy (24.96-28.80 Gy). The investigated outcome variables, GI toxicity, GU toxicity, erectile dysfunction, and IPSS were prospectively scored at several time points during follow-up. Association between time (as continuous and categorical variable) and the outcome variables was assessed using generalized linear models.
  
  
  RESULTS
  No statistically significant association was found between time (continuous) and GI toxicity (odds ratio [OR], 0.97; 95% confidence interval [CI], 0.89-1.06), GU toxicity (OR, 0.97; 95% CI, 0.91-1.03), erectile dysfunction (OR, 1.06; 95% CI, 0.99-1.11), and IPSS (-0.11; 95% CI, -0.41-0.20). Also, no statistically significant association was found between these variables and time as a categorical variable. GU toxicity was associated with IPSS resolution (OR, 1.16; 95% CI, 1.09-1.24). Posttreatment IPSS was associated with pretreatment IPSS (0.52; 95% CI, 0.25-0.79).
  
  
  CONCLUSIONS
  No accumulation of high-grade toxicity over time could be established for a group of patients treated with EBRT and PDR brachytherapy for prostate cancer, probably because high-grade late toxicity resolves with time. Also, differences in IPSS values among patients are smaller after treatment than before treatment.
authors.affiliation: Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, The Netherlands. b.r.pieters@amc.uva.nl
authors.forename: Bradley R
authors.initials: BR
authors.lastname: Pieters
authors.forename: Elisa
authors.initials: E
authors.lastname: Rezaie
authors.forename: Elisabeth D
authors.initials: ED
authors.lastname: Geijsen
authors.forename: Kees
authors.initials: K
authors.lastname: Koedooder
authors.forename: Johan N B
authors.initials: JN
authors.lastname: van der Grient
authors.forename: Leo E C M
authors.initials: LE
authors.lastname: Blank
authors.forename: Theo M
authors.initials: TM
authors.lastname: de Reijke
authors.forename: Caro C E
authors.initials: CC
authors.lastname: Koning
mesh_terms: D000368:Aged; D001918:Brachytherapy / Q000009:adverse effects / Q000379:methods; D007172:Erectile Dysfunction / Q000209:etiology*; D041981:Gastrointestinal Tract / Q000528:radiation effects*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000532:radiotherapy*; D011879:Radiotherapy Dosage; D013997:Time Factors; D014566:Urogenital System / Q000528:radiation effects*