The early adoption of intensity-modulated radiotherapy and stereotactic body radiation treatment among older Medicare beneficiaries with prostate cancer.

BACKGROUND: Several new prostate cancer treatments have emerged since 2000, including 2 radiotherapies with similar efficacy at the time of their introduction: intensity-modulated radiotherapy (IMRT) and stereotactic body radiation therapy (SBRT). The objectives of this study were to compare their early adoption patterns and identify factors associated with their use.
METHODS: By using the Surveillance, Epidemiology, and End Results (SEER)-Medicare database, patients who received radiation therapy during the 5 years after IMRT introduction (2001-2005) and the 5 years after SBRT introduction (2007-2011) were identified. The outcome of interest was the receipt of new radiation therapy (ie, IMRT or SBRT) compared with the existing standard radiation therapies at that time. The authors fit a series of multivariable, hierarchical logistic regression models accounting for patients nested within health service areas to examine the factors associated with the receipt of new radiation therapy.
RESULTS: During 2001 to 2005, 5680 men (21%) received IMRT compared with standard radiation (n = 21,555). Men who received IMRT were older, had higher grade tumors, and lived in more populated areas (P < .05). During 2007 through 2011, 595 men (2%) received SBRT compared with standard radiation (n = 28,255). Men who received ng SBRT were more likely to be white, had lower grade tumors, lived in more populated areas, and were more likely to live in the Northeast (P < .05). Adjusting for cohort demographic and clinical factors, the early adoption rate for IMRT was substantially higher than that for SBRT (44% vs 4%; P < .01).
CONCLUSIONS: There is a stark contrast in the adoption rates of IMRT and SBRT at the time of their introduction. Further investigation of the nonclinical factors associated with this difference is warranted. Cancer 2017;123:2945-54.