title: Outcomes following iodine-125 prostate brachytherapy with or without neoadjuvant androgen deprivation.
abstract: OBJECTIVE
  To report the biochemical failure-free survival (BFFS), cause-specific survival (CSS), and overall survival (OS) outcomes of patients treated with iodine-125 (I-125) brachytherapy for clinically localized prostate cancer.
  
  
  METHODS
  Between 2003 and 2009, I-125 permanent prostate brachytherapy without supplemental external-beam radiotherapy was performed for 663 patients with low-risk and low-tier intermediate-risk (defined as organ-confined disease, PSA <10ng/mL, and Gleason score 3+4 with biopsy positive core rate <33%) prostate cancer. Early in the study period, the preplanning method was used in the first 104 patients, and later the real-time planning method was used. Biochemical failure was determined using the American Society for Therapeutic Radiology Oncology (ASTRO) and Phoenix definitions.
  
  
  RESULTS
  The 7-year BFFS rates for the ASTRO and Phoenix definitions were 96.1% and 95.9%, respectively. The corresponding BFFS rates by risk group were 97.6% and 96.7% for low-risk, and 91.8% and 93.6% for low-tier intermediate-risk disease (p=0.007 and 0.08, respectively). The median times to biochemical failure in those who failed were 29.5 and 43.9months according to the ASTRO and Phoenix definitions, respectively. The 7-year CSS and OS were 99.1% and 96.4%. There was no significant difference in CSS or OS between the low-risk and low-tier intermediate-risk groups. In multivariate Cox regression analysis, risk group and prostate D90 were independent predictors of BFFS for the ASTRO definition, while only the prostate D90 was significant for the Phoenix definition.
  
  
  CONCLUSIONS
  I-125 prostate brachytherapy results in excellent 7-year BFFS, CSS, and OS for low-risk and low-tier intermediate-risk prostate cancer.
authors.affiliation: Department of Radiology, Keio University School of Medicine, Tokyo, Japan; Department of Radiology, National Hospital Organization Saitama Hospital, Japan. Electronic address: ohashi@rad.med.keio.ac.jp.
authors.forename: Toshio
authors.initials: T
authors.lastname: Ohashi
authors.forename: Atsunori
authors.initials: A
authors.lastname: Yorozu
authors.forename: Shiro
authors.initials: S
authors.lastname: Saito
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Momma
authors.forename: Kazuhito
authors.initials: K
authors.lastname: Toya
authors.forename: Toru
authors.initials: T
authors.lastname: Nishiyama
authors.forename: Shoji
authors.initials: S
authors.lastname: Yamashita
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Shiraishi
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Shigematsu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001918:Brachytherapy / Q000009:adverse effects / Q000379:methods*; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D016016:Proportional Hazards Models; D011471:Prostatic Neoplasms / Q000401:mortality / Q000532:radiotherapy*; D011879:Radiotherapy Dosage; D016896:Treatment Outcome
chemical_list: D007457:Iodine Radioisotopes
keywords: Brachytherapy; Prostate cancer; Seed implant