Yvonne D Pham1, Jeffrey A Kittel1, Chandana A Reddy1, Jay P Ciezki1, Eric A Klein2, Kevin L Stephans1, Rahul D Tendulkar3. 1. Department of Radiation Oncology, Cleveland Clinic Taussig Cancer Institute, Cleveland, OH. 2. Department of Urology, Cleveland Clinic Glickman Urological and Kidney Institute, Cleveland, OH. 3. Department of Radiation Oncology, Cleveland Clinic Taussig Cancer Institute, Cleveland, OH. Electronic address: Tendulr@ccf.org.
Abstract
PURPOSE: 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 AND MATERIALS: 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.
PURPOSE: We sought to analyze whether outcomes of biochemical relapse-free survival (bRFS), late genitourinary (GU), and late gastrointestinal toxicity are different for prostate cancerpatients with small (≤60 cc) vs. large (>60 cc) prostates following low dose-rate brachytherapy. METHODS AND MATERIALS: The bRFS outcomes for 2076 low- or intermediate-risk prostate cancerpatients 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.