title: High dose brachytherapy as monotherapy for intermediate risk prostate cancer.
abstract: OBJECTIVE
  We evaluated our retrospective, single institution experience with high dose rate brachytherapy as monotherapy for intermediate risk prostate cancer.
  
  
  METHODS
  Our cohort included 284 patients with intermediate risk prostate cancer, defined as clinical stage T2b/T2c, Gleason score 7 and/or prostate specific antigen 10 to 20 ng/ml, and 1-year minimum followup. Treatment was 2 high dose rate brachytherapy sessions at 3 fractions of 6.5 Gy each for a mean of 19 days. Prostate specific antigen failure was defined as nadir +2 ng/ml.
  
  
  RESULTS
  Mean followup was 35.1 months (median 31.9). Actuarial 5-year cause specific survival and clinical local control were 100%, distant-metastasis-free survival 98.8% and biochemical disease-free survival 94.4%. Clinical stage predicted biochemical disease-free survival. For stage T2a or less 5-year biochemical disease-free survival was 95.1% vs 100% for stage T2b and 77.4% for T2c (p = 0.012). Percent positive biopsy cores and prostate specific antigen nadir were also predictive. International Prostate Symptom Score results remained stable and potency was maintained in 82.6% of patients at 2 years. Pads were used for the first time after brachytherapy in 22 patients (7.7%), mostly for grade 1 incontinence (occasionally or less per week). Excluding patients with prior transurethral prostatectomy, stroke or tremor 2.5% used pads for the first time after treatment. No patient had urethral stricture. Radiation Therapy Oncology Group grade 1 rectal toxicity developed in 12 patients (4.2%) but not beyond grade 1.
  
  
  CONCLUSIONS
  High dose rate brachytherapy as monotherapy is safe and effective for patients with intermediate risk prostate cancer. We recommend caution for percent positive biopsy cores exceeding 75% or clinical stage T2c. Excluding such patients the 5-year biochemical disease-free survival rate was 97.5%.
authors.affiliation: GammaWest Cancer Services, Salt Lake City, Utah, USA. Leland@GammaWest.com
authors.forename: C Leland
authors.initials: CL
authors.lastname: Rogers
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Alder
authors.forename: R LeGrand
authors.initials: RL
authors.lastname: Rogers
authors.forename: Scott A
authors.initials: SA
authors.lastname: Hopkins
authors.forename: McKay L
authors.initials: ML
authors.lastname: Platt
authors.forename: Lane C
authors.initials: LC
authors.lastname: Childs
authors.forename: Ronald H
authors.initials: RH
authors.lastname: Crouch
authors.forename: Roger S
authors.initials: RS
authors.lastname: Hansen
authors.forename: John K
authors.initials: JK
authors.lastname: Hayes
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001918:Brachytherapy / Q000009:adverse effects / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000532:radiotherapy*; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D012307:Risk Factors