Is proton beam therapy cost effective in the treatment of adenocarcinoma of the prostate?

PURPOSE New treatments are introduced routinely into clinical practice without rigorous economic analysis. The specific aim of this study was to examine the cost effectiveness of proton beam radiation compared with current state-of-the art therapy in the treatment of patients with prostate cancer. MATERIALS AND METHODS A Markov model was informed with cost, freedom from biochemical failure (FFBF), and utility data obtained from the literature and from patient interviews to compare the cost effectiveness of 91.8 cobalt gray equivalent (CGE) delivered with proton beam versus 81 CGE delivered with intensity-modulated radiation therapy (IMRT). The length of how many years the model was run, patient's age, probability of FFBF after treatment with proton beam therapy and IMRT, utility of patients treated with salvage hormone therapy, and treatment cost were tested in sensitivity analyses. RESULTS Analysis at 15 years resulted in an expected mean cost of proton beam therapy and IMRT of $63,511 and $36,808, and $64,989 and $39,355 for a 70-year-old and 60-year-old man respectively, with quality-adjusted survival of 8.54 and 8.12 and 9.91 and 9.45 quality-adjusted life-years (QALY), respectively. The incremental cost effectiveness ratio was calculated to be $63,578/QALY for a 70-year-old man and $55,726/QALY for a 60-year-old man. CONCLUSION Even when based on the unproven assumption that protons will permit a 10-Gy escalation of prostate dose compared with IMRT photons, proton beam therapy is not cost effective for most patients with prostate cancer using the commonly accepted standard of $50,000/QALY. Consideration should be given to limiting the number of proton facilities to allow comprehensive evaluation of this modality.