title: Dose escalation for prostate cancer using the three-dimensional conformal dynamic arc technique: analysis of 542 consecutive patients.
abstract: OBJECTIVE
  To present the results of dose escalation using three-dimensional conformal dynamic arc radiotherapy (3D-ART) for prostate cancer.
  
  
  METHODS
  Five hundred and forty two T1-T3N0M0 prostate cancer patients were treated with 3D-ART. Dose escalation (from 76 Gy/38 fractions to 80 Gy/40 fractions) was introduced in September 2003; 32% of patients received 80 Gy. In 366 patients, androgen deprivation was added to 3D-ART. Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer criteria and Houston definition (nadir + 2) were used for toxicity and biochemical failure evaluation, respectively. Median follow-up was 25 months.
  
  
  RESULTS
  Acute toxicity included rectal (G1-2 28.9%; G3 0.5%) and urinary events (G1-2 57.9%; G3-4 2.4%). Late toxicity included rectal (G1-2 15.8%; G3-4 3.1%) and urinary events (G1-2 26.9%; G3-4 1.6%). Two-year failure-free survival and overall survival rates were 94.1% and 97.9%, respectively. Poor prognostic group (GS, iPSA, T), transurethral prostate resection, and dose >76 Gy showed significant association to high risk of progression in multivariate analysis (p = 0.014, p = 0.045, and p = 0.04, respectively). The negative effect of dose >76 Gy was not observed (p = 0.10), when the analysis was limited to 353 patients treated after September 2003 (when dose escalation was introduced). Higher dose was not associated with higher late toxicity.
  
  
  CONCLUSIONS
  Three-dimensional-ART is a feasible modality allowing for dose escalation (no increase in toxicity has been observed with higher doses). However, the dose increase from 76 to 80 Gy was not associated with better tumor outcome. Further investigation is warranted for better understanding of the dose effect for prostate cancer.
authors.affiliation: Department of Radiotherapy, European Institute of Oncology, Milan, Italy. barbara.jereczek@ieo.it
authors.forename: Barbara A
authors.initials: BA
authors.lastname: Jereczek-Fossa
authors.forename: Andrea
authors.initials: A
authors.lastname: Vavassori
authors.forename: Cristiana
authors.initials: C
authors.lastname: Fodor
authors.forename: Luigi
authors.initials: L
authors.lastname: Santoro
authors.forename: Dario
authors.initials: D
authors.lastname: Zerini
authors.forename: Federica
authors.initials: F
authors.lastname: Cattani
authors.forename: Cristina
authors.initials: C
authors.lastname: Garibaldi
authors.forename: Raffaella
authors.initials: R
authors.lastname: Cambria
authors.forename: Andrei
authors.initials: A
authors.lastname: Fodor
authors.forename: Genoveva Ionela
authors.initials: GI
authors.lastname: Boboc
authors.forename: Viviana
authors.initials: V
authors.lastname: Vitolo
authors.forename: Giovanni Battista
authors.initials: GB
authors.lastname: Ivaldi
authors.forename: Gennaro
authors.initials: G
authors.lastname: Musi
authors.forename: Ottavio
authors.initials: O
authors.lastname: de Cobelli
authors.forename: Roberto
authors.initials: R
authors.lastname: Orecchia
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015897:Comorbidity; D004307:Dose-Response Relationship, Radiation; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011471:Prostatic Neoplasms / Q000453:epidemiology* / Q000532:radiotherapy*; D011832:Radiation Injuries / Q000453:epidemiology*; D011879:Radiotherapy Dosage; D020266:Radiotherapy, Conformal / Q000379:methods* / Q000706:statistics & numerical data*; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D016896:Treatment Outcome