title: Relationships between bladder dose-volume/surface histograms and acute urinary toxicity after radiotherapy for prostate cancer.
abstract: OBJECTIVE
  DUE01 is an observational study aimed at developing predictive models of genito-urinary toxicity of patients treated for prostate cancer with conventional (1.8-2Gy/fr, CONV) or moderate hypo-fractionation (2.35-2.7Gy/fr, HYPO). The current analysis focused on the relationship between bladder DVH/DSH and the risk of International Prostate Symptoms Score (IPSS)⩾15/20 at the end of radiotherapy.
  
  
  METHODS
  Planning and relevant clinical parameters were prospectively collected, including DVH/DSH, LQ-corrected (DVHc/DSHc) and weekly (DVHw/DSHw) histograms. Best parameters were selected by the differences between patients with/without IPSS⩾15/20 at the end of radiotherapy. Logistic uni- and backward multi-variable (MVA) analyses were performed.
  
  
  RESULTS
  Data of 247 patients were available (CONV: 116, HYPO: 131). Absolute DVHw/DSHw and DVHc/DSHc predicted the risk of IPSS⩾15 at the end of radiotherapy (n=77/247); an MVA model including baseline IPSS, anti-hypertensive, T stage, the absolute surface receiving ⩾8.5Gy/week and ⩾12.5Gy/week was developed (AUC=0.78, 95% CI: 0.72-0.83). Similar AUC values were found if replacing DSHw with DVHw/DVHc/DSHc parameters. The impact of dose-volume/surface parameters remained when excluding patients with baseline IPSS⩾15 and in HYPO. IPSS⩾20 at the end of radiotherapy (n=27/247) was mainly correlated to baseline IPSS and T stage.
  
  
  CONCLUSIONS
  Although the baseline IPSS was the main predictor, constraining v8.5w<56cc and v12.5w<5cc may significantly reduce acute GU toxicity.
authors.affiliation: Medical Physics, San Raffaele Scientific Institute, Milano, Italy.
authors.forename: Viviana
authors.initials: V
authors.lastname: Carillo
authors.affiliation: Radiotherapy, San Raffaele Scientific Institute, Milano, Italy.
authors.forename: Cesare
authors.initials: C
authors.lastname: Cozzarini
authors.affiliation: Prostate Cancer Program, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
authors.forename: Tiziana
authors.initials: T
authors.lastname: Rancati
authors.affiliation: Radiation Oncology 1, Fondazione IRCCS Istituto Nazionale dei Tumori, Milano, Italy.
authors.forename: Barbara
authors.initials: B
authors.lastname: Avuzzi
authors.affiliation: Medical Physics, Arcispedale S.M. Nuova, Reggio Emilia, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Botti
authors.affiliation: Medical Physics, Ospedale ASL9, Ivrea, Italy.
authors.forename: Valeria Casanova
authors.initials: VC
authors.lastname: Borca
authors.affiliation: Radiotherapy, IRCCS-Candiolo, Italy.
authors.forename: Gabriella
authors.initials: G
authors.lastname: Cattari
authors.affiliation: Prostate Cancer Program, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Civardi
authors.affiliation: Radiotherapy, Ospedale Bellaria, Bologna, Italy.
authors.forename: Claudio Degli
authors.initials: CD
authors.lastname: Esposti
authors.affiliation: Radiotherapy, Ospedale Regionale U.Parini-AUSL Valle d'Aosta, Aosta, Italy.
authors.forename: Pierfrancesco
authors.initials: P
authors.lastname: Franco
authors.affiliation: Radiotherapy, Ospedale ASL9, Ivrea, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Girelli
authors.affiliation: Medical Physics, IRCCS-Candiolo, Italy.
authors.forename: Angelo
authors.initials: A
authors.lastname: Maggio
authors.affiliation: Radiotherapy, Arcispedale S.M. Nuova, Reggio Emilia, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Muraglia
authors.affiliation: Medical Physics, Ospedale Bellaria, Bologna, Italy.
authors.forename: Marcella
authors.initials: M
authors.lastname: Palombarini
authors.affiliation: Medical Physics, Cliniche Gavazzeni-Humanitas, Bergamo, Italy.
authors.forename: Alessio
authors.initials: A
authors.lastname: Pierelli
authors.affiliation: Medical Physics, Fondazione IRCCS Istituto Nazionale dei Tumori, Milano, Italy.
authors.forename: Emanuele
authors.initials: E
authors.lastname: Pignoli
authors.affiliation: Radiotherapy, Cliniche Gavazzeni-Humanitas, Bergamo, Italy.
authors.forename: Vittorio
authors.initials: V
authors.lastname: Vavassori
authors.affiliation: Medical Physics, Ospedale Regionale U.Parini-AUSL Valle d'Aosta, Aosta, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Zeverino
authors.affiliation: Prostate Cancer Program, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy; Radiation Oncology 1, Fondazione IRCCS Istituto Nazionale dei Tumori, Milano, Italy.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Valdagni
authors.affiliation: Medical Physics, San Raffaele Scientific Institute, Milano, Italy. Electronic address: fiorino.claudio@hsr.it.
authors.forename: Claudio
authors.initials: C
authors.lastname: Fiorino
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019583:Dose Fractionation, Radiation; D004307:Dose-Response Relationship, Radiation; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011471:Prostatic Neoplasms / Q000532:radiotherapy*; D011832:Radiation Injuries / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D011879:Radiotherapy Dosage; D001743:Urinary Bladder / Q000503:physiopathology / Q000528:radiation effects*; D014570:Urologic Diseases / Q000209:etiology* / Q000503:physiopathology
keywords: Dose–volume effects; Prostate cancer; Radiotherapy; Urinary toxicity