Cost Analysis Of High Vs. Low Activity Iodine-125 Seeds As Monotherapy For Permanent Prostate Brachytherapy.

4717 Background: We have previously reported the differences in post-implant parameters for high and low activity I-125 seeds for permanent prostate brachytherapy (PPB). We have also reported similar rates of PSA relapse-free survival (RFS) and GI/GU morbidity. This study is a cost analysis of higher vs. lower activity radioactive seeds used for PPB in the treatment of localized adenocarcinoma of the prostate. Methods: Treatment plans for 174 patients receiving I-125 PPB as monotherapy for localized adenocarcimona of the prostate were reviewed. Pre-treatment planning was performed for all patients using the ASTRO guidelines for PPB. Specific activity (mCi/cc) was determined for prostate volumes which ranged from 13.8 to 71.1 cc. Current prices for individual model 6711 I-125 seeds were obtained from the manufacturer (Oncura). Total seed costs for implants utilizing 0.450 mCi (67 patients) and 0.326 mCi (107 patients) radioactive seeds were compared. Results: The median prostate volumes for patients receiving implants utilizing 0.450 mCi and 0.326 mCi seeds were 40.0 and 41.1 cc respectively. The mean specific activity for both groups was equal (0.87 ± 0.02 mCi/cc). Cost per I-125 seed was $45. The median (mean) number of seeds per cc for 0.450 mCi and 0.326 mCi implants were 1.9 and 2.7 (1.9 ± 0.33 and 2.7 ± 0.43) respectively, resulting in a median of 42 % more seeds required for 0.326 mCi implants. This translated to a median cost of $3,452 per 0.450 mCi implant vs. $4,884 per 0.326 mCi implant, corresponding to a $1,432 price differential per patient based on a median population prostate volume of 40.8 cc. Conclusions: Based upon current prices for I-125 radioactive seeds, there is a significant cost advantage to the use of higher vs. lower activity seeds in PPB for localized adenocarcinoma of the prostate. Previously reported data suggests similar morbidity and PSA RFS between implants utilizing either seed activity. No significant financial relationships to disclose.