In a comparison of outcomes and costs for 310 patients who underwent SBRT matched with 3,100 who underwent IMRT, the investigators found no significant differences in composite urinary, erectile dysfunction, or bowel toxicities. However, the risk of urinary fistula, while low, was significantly higher with SBRT compared with IMRT, with rates of 1% vs. 0.1%, respectively (P = .009).
The mean cost of SBRT in this analysis was $49,504, compared with $57,244 for IMRT (P less than .001).
The investigators acknowledged that by using claims data they were unable to plug information about potential confounding factors such as Gleason score, prostate-specific antigen level, clinical stage, or radiation field and dose into their propensity-score models. They also noted that follow-up was relatively short because of the vicissitudes of the U.S. insurance market, which causes many patients to change insurers frequently.
The study was supported by grants from the National Cancer Institute and by Varian Medical Systems. Dr. Smith, lead author Hubert Y. Pan, MD, and others disclosed research support, consulting, and/or travel support from Varian.
SOURCE: Smith BD et al. J Clin Oncol. 2018 Mar 21. doi: 10.1200/JCO.2017.75.5371.