title: Moderate dose escalation in three-dimensional conformal localized prostate cancer radiotherapy: single-institutional experience in 398 patients comparing 66 Gy versus 70 Gy versus 74 Gy.
abstract: OBJECTIVE
  To evaluate the clinical outcome in prostate cancer patients treated at one single institution by the implementation of moderate dose escalation.
  
  
  METHODS
  A total of 398 patients with histologically verified localized prostate cancer (T1-3 Nx0 Mx0) were treated by three-dimensional conformal radiotherapy with/without additional hormonal therapy. Risk group distribution was as follows: 106 low-risk (27%), 164 intermediate-risk (41%), and 128 high-risk (32%) patients. Total local dose was increased from 66 Gy (1994-1998) to 70 Gy (1998-2003) and 74 Gy (1998-2005). Biochemical no evidence of disease (bNED: ASTRO/Phoenix definition) and late gastrointestinal/urogenital side effects (EORTC/RTOG) were assessed.
  
  
  RESULTS
  Median follow-up was 64 months. The 5-year bNED rates according to 66 Gy, 70 Gy and 74 Gy were 37%, 64% and 63% (ASTRO), and 54%, 74% and 69% (Phoenix), respectively. In multivariate analysis, age and T-stage were significant in predicting bNED. The 5-year bNED rates (ASTRO) according to 66 Gy, 70 Gy and 74 Gy were 40%, 78% and 73% in the low-risk group, 41%, 55% and 85% in the intermediate-risk group, and 30%, 53% and 52% in the high-risk group. Intermediate-risk patients showed a significant improvement of bNED by increasing the dose up to 74 Gy. The 5-year actuarial rates of gastrointestinal/urogenital side effects grade > or = 2 were 18%/16% (66 Gy), 20%/24% (70 Gy), and 27%/28% (74 Gy).
  
  
  CONCLUSIONS
  A benefit of local doses at a level of > or = 70 Gy could be detected showing the highest increase of prostate-specific antigen control in the intermediate-risk group. The amount of patients reporting of severe late side effects is small.
authors.affiliation: Department of Radiotherapy, University of Vienna Medical School, Vienna, Austria. Gregor.Goldner@akhwien.at
authors.forename: Gregor
authors.initials: G
authors.lastname: Goldner
authors.forename: Johannes
authors.initials: J
authors.lastname: Dimopoulos
authors.forename: Christian
authors.initials: C
authors.lastname: Kirisits
authors.forename: Richard
authors.initials: R
authors.lastname: Pötter
mesh_terms: D000230:Adenocarcinoma / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019583:Dose Fractionation, Radiation; D005500:Follow-Up Studies; D041981:Gastrointestinal Tract / Q000528:radiation effects; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D011471:Prostatic Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D011832:Radiation Injuries / Q000209:etiology; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D020266:Radiotherapy, Conformal / Q000379:methods*; D014566:Urogenital System / Q000528:radiation effects