title: High-dose-rate brachytherapy boost for prostate cancer: comparison of two different fractionation schemes.
abstract: OBJECTIVE
  This is a retrospective study comparing our experience with high-dose-rate (HDR) brachytherapy boost for prostate cancer, using two different fractionation schemes, 600 cGy × 3 fractions (patient group 1) and 950 cGy × 2 fractions (patient group 2).
  
  
  METHODS
  A total of 165 patients were treated for prostate cancer using external beam radiation therapy up to a dose of 45 Gy, followed by an HDR brachytherapy prostate radiation boost. Between July 1997 and Nov 1999, 64 patients were treated with an HDR boost of 600 cGy × 3 fractions; and between June 2000 and Nov 2005, 101 patients were treated with an HDR boost of 950 cGy × 2 fractions. All but 9 patients had at least one of the following risk features: pretreatment prostate-specific antigen (PSA) level >10, a Gleason score ≥7, and/or clinical stage T3 disease.
  
  
  RESULTS
  Median follow-up was 105 months for group 1 and 43 months for group 2. Patients in group 2 had a greater number of high-risk features than group 1 (p = 0.02). Adjusted for comparable follow-up, there was no difference in biochemical no-evidence-of-disease (bNED) rate between the two fractionation scheme approaches, with 5-year Kaplan-Meier estimates of 93.5% in group 1 and 87.3% in group 2 (p = 0.19). The 5-year estimates of progression-free survival were 86% for group 1 and 83% for group 2 (p = 0.53). Among high-risk patients, there were no differences in bNED or PFS rate due to fractionation.
  
  
  CONCLUSIONS
  Results were excellent for both groups. Adjusted for comparable follow-up, no differences were found between groups.
authors.affiliation: Department of Radiation Oncology, University of California, San Francisco Helen Diller Family Comprehensive Cancer Center, San Francisco, California 94115, USA.
authors.forename: Tania
authors.initials: T
authors.lastname: Kaprealian
authors.forename: Vivian
authors.initials: V
authors.lastname: Weinberg
authors.forename: Joycelyn L
authors.initials: JL
authors.lastname: Speight
authors.forename: Alexander R
authors.initials: AR
authors.lastname: Gottschalk
authors.forename: Mack
authors.initials: M
authors.lastname: Roach
authors.forename: Katsuto
authors.initials: K
authors.lastname: Shinohara
authors.forename: I-Chow
authors.initials: IC
authors.lastname: Hsu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001918:Brachytherapy / Q000009:adverse effects / Q000379:methods*; D018572:Disease-Free Survival; D019583:Dose Fractionation, Radiation; D057918:Fiducial Markers; D006801:Humans; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000097:blood / Q000473:pathology / Q000532:radiotherapy*; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D016896:Treatment Outcome
chemical_list: D017430:Prostate-Specific Antigen