Evaluation of potential proton therapy utilization in a market-based environment

Proton therapy is an increasingly prominent radiation treatment modality. Market-driven adoption of proton therapy into routine clinical practice may have a significant economic impact. The aim of this study was to estimate the proportion of patients who could potentially be treated with proton therapy by evaluating the utilization of existing highly conformal photon therapy as a proxy.

All patients treated in 2007 with radiation therapy at the authors' institution were evaluated. Treatment technique was categorized using Current Procedural Terminology((R)) codes as conventional radiation therapy, intensity-modulated radiation therapy, Gamma Knife radiosurgery, stereotactic body radiation therapy, and brachytherapy. Medicare 2008 codes were used to estimate cost impact.

One thousand forty-two patients were treated using 19,749 treatment fractions. As a potential proxy for proton therapy, highly conformal external-beam photon techniques were delivered in 31% of all fractions (intensity-modulated radiation therapy in 30%, stereotactic body radiation therapy in <1%, and Gamma Knife radiosurgery in 1%). Most were used for prostate cancer (37%), gliomas (17%), and head and neck cancers (16%). Pediatric patients were a small proportion (2%) of treatments. Proton therapy, if delivered instead of highly conformal photon therapy, could increase annual cost for radiation therapy at the authors' institution by $1.3 million (22%) and require approximately 1.4 gantries to deliver.

Using existing utilization patterns of highly conformal photon therapy as a proxy, approximately one-third of patients irradiated annually at the authors' institution could be treated with proton therapy, with an incremental cost of 20% across the entire treated patient population.