RESUMO
PURPOSE: The recently published ASCENDE-RT randomized clinical trial demonstrated improved biochemical control, albeit with increased toxicity, for a prostate boost with brachytherapy versus external beam radiation therapy alone in patients with intermediate-high risk prostate cancer. In this study, we investigated the cost-effectiveness of these two modalities in the treatment of intermediate-high risk prostate cancer. METHODS AND MATERIALS: A multistate Markov model was created to model a patient with intermediate-high risk prostate cancer. The two treatment options modeled were (1) 23 fractions of intensity-modulated radiation therapy (IMRT) and two fractions of high-dose-rate prostate brachytherapy (brachytherapy boost) and (2) 44 fractions of IMRT (IMRT alone). Each patient received 1 year of hormone therapy, per the ASCENDE-RT protocol. Model assumptions, including clinical outcomes, toxicity, and utilities were derived from the medical literature. Costs of radiation therapy were estimated using Medicare reimbursement data. RESULTS: The estimated expected lifetime cost of brachytherapy boost was $68,696, compared to $114,944 for IMRT alone. Brachytherapy boost significantly lowered expected lifetime treatment costs because it decreased the incidence of metastatic castration-resistant prostate cancer, cutting the use of expensive targeted therapy for metastatic castration-resistant prostate cancer. Brachytherapy boost had an expected quality-adjusted life years of 10.8 years, compared to 9.3 years for IMRT alone. One-way sensitivity analyses of our results found brachytherapy boost to be cost-effective over a wide range of cost, utility, and cancer progression rate assumptions. CONCLUSIONS: IMRT with high-dose-rate brachytherapy boost is a cost-effective treatment for intermediate-high risk prostate cancer compared to IMRT alone.