Utilization trend and regimens of hypofractionated whole breast radiation therapy in the United States.

PURPOSE: We aimed to evaluate the adoption of hypofractionated whole-breast irradiation (HF-WBI) over time and factors related to its adoption for patients undergoing lumpectomy. We also examined whether HF-WBI can increase the overall use of radiotherapy.

METHODS: Using data from the National Cancer Database between 2004 and 2013, we identified 528,051 invasive and 190,431 ductal carcinoma in situ (DCIS) patients who underwent lumpectomy. HF-WBI was defined as 2.5-3.33 Gy/fraction to the breast, whereas conventional therapy (CF-WBI) was defined as 1.8-2.0 Gy/fraction.

RESULTS: The usage of HF-WBI among invasive cancer patients increased from 0.7% in 2004 to 15.6% in 2013, and among DCIS patients, HF-WBI increased from 0.4% in 2004 to 13.4% in 2013. However, these changes only lead to a slight increase in the overall use of radiotherapy. Interestingly, for DCIS patients who lived ≥50 miles from hospitals, the uptake of HF-WBI translated to a moderate increase in the overall use of radiotherapy (58% in 2004 to 63% in 2013). Multivariable logistic regression showed that older age, node-negative or smaller tumor, living in mountain states, rural area, or ≥50 miles from hospitals, and treated in large or academic cancer centers were associated with elevated HF-WBI use. The median duration of finishing radiotherapy for HF-WBI was 26 days, compared to 47 days for CF-WBI.

CONCLUSIONS: Although HF-WBI can save 3 weeks of patient time, its adoption remained low in the US. There was only a slight increase in the overall use of radiotherapy among patients undergoing lumpectomy.