title: Comparison of tumor control and toxicity outcomes of high-dose intensity-modulated radiotherapy and brachytherapy for patients with favorable risk prostate cancer.
abstract: OBJECTIVE
  To compare the long-term, prostate-specific antigen relapse-free survival outcome and incidence of toxicity for patients with low-risk prostate cancer who underwent brachytherapy or intensity-modulated radiotherapy (RT).
  
  
  METHODS
  A total of 729 consecutive patients underwent brachytherapy (n = 448; prescription dose 144 Gy) or intensity-modulated RT alone (n = 281; prescription dose 81 Gy). The prostate-specific antigen relapse-free survival using the nadir plus 2 ng/mL definition and late toxicity using the National Cancer Institute's Common Terminology Criteria for Adverse Events were determined.
  
  
  RESULTS
  The 7-year prostate-specific antigen relapse-free survival rate for the brachytherapy and intensity-modulated RT groups was 95% and 89% for low-risk patients, respectively (P = .004). Cox regression analysis demonstrated that brachytherapy was associated with improved prostate-specific antigen relapse-free survival, even after adjustment for other variables. The incidence of metastatic disease between treatment sessions was low for both treatment groups. Late grade 2 gastrointestinal toxicity was observed in 5.1% and 1.4% of the brachytherapy and intensity-modulated RT groups, respectively (P = .02). No significant differences were seen between treatment groups for late grade 3 or greater rectal complications (brachytherapy 1.1% and intensity-modulated RT 0%; P = .19). Late grade 2 urinary toxicity occurred more often in the brachytherapy group than in the intensity-modulated RT group (15.6% and 4.3%, respectively; P < .0001). No significant differences were seen between the 2 treatment groups for late grade 3 urinary toxicity (brachytherapy 2.2% and intensity-modulated RT 1.4%; P = .62).
  
  
  CONCLUSIONS
  Among low-risk prostate cancer patients, the 7-year biochemical tumor control was superior for intraoperatively planned brachytherapy compared with high-dose intensity-modulated RT. Although significant toxicities were minimal for both groups, modest, but significant, increases in grade 2 urinary and rectal symptoms were noted for brachytherapy compared with intensity-modulated RT.
authors.affiliation: Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA. zelefskm@mskcc.org
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Zelefsky
authors.forename: Yoshiya
authors.initials: Y
authors.lastname: Yamada
authors.forename: Xin
authors.initials: X
authors.lastname: Pei
authors.forename: Margie
authors.initials: M
authors.lastname: Hunt
authors.forename: Gilad
authors.initials: G
authors.lastname: Cohen
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Zhang
authors.forename: Marco
authors.initials: M
authors.lastname: Zaider
mesh_terms: D001918:Brachytherapy / Q000009:adverse effects; D006801:Humans; D008297:Male; D010410:Penile Erection / Q000528:radiation effects; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000401:mortality / Q000532:radiotherapy*; D011878:Radiotherapy / Q000009:adverse effects / Q000379:methods; D011879:Radiotherapy Dosage; D020266:Radiotherapy, Conformal; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D017430:Prostate-Specific Antigen