title: Outcomes for prostate glands >60 cc treated with low-dose-rate brachytherapy.
abstract: OBJECTIVE
  We sought to analyze whether outcomes of biochemical relapse-free survival (bRFS), late genitourinary (GU), and late gastrointestinal toxicity are different for prostate cancer patients with small (≤60 cc) vs. large (>60 cc) prostates following low dose-rate brachytherapy.
  
  
  METHODS
  The bRFS outcomes for 2076 low- or intermediate-risk prostate cancer patients from 1996 to 2012 were determined from a review of a prospectively maintained database. All patients were treated with (125)I monotherapy without androgen deprivation therapy. Biochemical failure was defined per the Phoenix definition. Patient-related factors and dosimetric values were examined in Cox regression analyses for bRFS and late toxicity. Late toxicity was scored according to a modified Common Terminology Criteria for Adverse Events version 4.0 scale.
  
  
  RESULTS
  The median followup for all patients was 55 months. The 5-year bRFS rates for all patients, prostates >60 cc, and prostates ≤60 cc were 93.4% (95% confidence interval [CI]: 92.1%, 94.7%), 96.7% (95% CI: 94.4%, 98.9%), and 92.9% (95% CI: 91.4%, 94.3%), respectively. On multivariable analysis, prostate size >60 cc was significantly associated with improved bRFS (p = 0.01), as were initial prostate-specific antigen and biopsy Gleason score (p < 0.0001 and p = 0.0002, respectively). Patients with prostates >60 cc had significantly higher rates of Grade 3-4 late GU toxicity at 5 years than patients with smaller prostates; 7.2% (95% CI: 4.0%, 10.4%) and 3.2% (95% CI: 2.3%, 4.1%), respectively (p = 0.0007). The overall late gastrointestinal toxicity rate for all patients was 0.7% at 5 years with no significant difference between the two groups.
  
  
  CONCLUSIONS
  Implantation of large prostates >60 cc results in favorable bRFS outcomes and is associated with increased but acceptable rates of Grade 3 and higher late GU toxicities.
authors.affiliation: Department of Radiation Oncology, Cleveland Clinic Taussig Cancer Institute, Cleveland, OH.
authors.forename: Yvonne D
authors.initials: YD
authors.lastname: Pham
authors.affiliation: Department of Radiation Oncology, Cleveland Clinic Taussig Cancer Institute, Cleveland, OH.
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Kittel
authors.affiliation: Department of Radiation Oncology, Cleveland Clinic Taussig Cancer Institute, Cleveland, OH.
authors.forename: Chandana A
authors.initials: CA
authors.lastname: Reddy
authors.affiliation: Department of Radiation Oncology, Cleveland Clinic Taussig Cancer Institute, Cleveland, OH.
authors.forename: Jay P
authors.initials: JP
authors.lastname: Ciezki
authors.affiliation: Department of Urology, Cleveland Clinic Glickman Urological and Kidney Institute, Cleveland, OH.
authors.forename: Eric A
authors.initials: EA
authors.lastname: Klein
authors.affiliation: Department of Radiation Oncology, Cleveland Clinic Taussig Cancer Institute, Cleveland, OH.
authors.forename: Kevin L
authors.initials: KL
authors.lastname: Stephans
authors.affiliation: Department of Radiation Oncology, Cleveland Clinic Taussig Cancer Institute, Cleveland, OH. Electronic address: Tendulr@ccf.org.
authors.forename: Rahul D
authors.initials: RD
authors.lastname: Tendulkar
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000726:Androgen Antagonists / Q000627:therapeutic use; D001706:Biopsy; D001918:Brachytherapy / Q000009:adverse effects / Q000379:methods; D018572:Disease-Free Survival; D005500:Follow-Up Studies; D041981:Gastrointestinal Tract / Q000528:radiation effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009929:Organ Size; D011467:Prostate / Q000473:pathology*; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000097:blood / Q000473:pathology* / Q000532:radiotherapy*; D011832:Radiation Injuries / Q000209:etiology*; D011868:Radioisotopes; D014566:Urogenital System / Q000528:radiation effects*
chemical_list: D000726:Androgen Antagonists; D011868:Radioisotopes; D017430:Prostate-Specific Antigen
keywords: Biochemical relapse–free survival; Gland; Large; Low dose-rate brachytherapy; Prostate cancer; Volume