Intensity-Modulated Radiation Therapy in Breast Cancer Patients Following the Release of a Choosing Wisely Recommendation.

In 2013, the American Society for Radiation Oncology recommended against the routine use of intensity-modulated radiation therapy (IMRT) in breast cancer patients. We evaluated trends in the use of IMRT before and after the release of the recommendation. Using Surveillance, Epidemiology, and End Results Medicare data, we identified 13 457 breast cancer patients diagnosed between 2012 and 2015 who received breast-conserving surgery and postsurgery, whole-breast, IMRT, or three-dimensional conformal radiotherapy. We find that the use of IMRT decreased by 4.6 (95% confidence interval [CI] = 3.6 to 5.6; two-sided P < .001) percentage points in hospital-based clinics. In freestanding radiotherapy clinics, which had baseline rates of IMRT use that were more than 20 percentage points higher than in hospital-based clinics, use of IMRT declined by 6.1 (95% CI = 3.5 to 8.7; two-sided P < .001) percentage points. Use of IMRT declined following the release of the recommendation, but a large share of patients treated in freestanding clinics continue to receive IMRT.