Radiotherapy Utilization and Fractionation Patterns During the First Course of Cancer Treatment in the United States From 2004 to 2014.

BACKGROUND: The changing use of radiation as a first-line cancer therapy in the United States is poorly characterized. This study aims to report radiotherapy utilization and fractionation patterns during the first course of cancer treatment.

METHODS: We extracted all solid tumor cases from 2004 to 2014 in the National Cancer Data Base, which captures only the first course of treatment. Patients were subcategorized by disease site: breast, central nervous system (CNS), gastrointestinal, genitourinary, gynecologic, head and neck (HN), musculoskeletal, skin, or thoracic. Receipt of therapy was identified (systemic, surgical, or radiation therapy). Radiotherapy was subcategorized as external beam radiation therapy (EBRT) (conventional and stereotactic), brachytherapy, and radio-isotopes. Radiotherapy was also characterized by intent (palliative or definitive). The percent of patients receiving therapy and in those receiving radiotherapy, the mean number of radiation treatments, or fractions, delivered over time were reported.

RESULTS: The utilization of radiotherapy among all cases declined from 33.9% to 31.2% (P < .001), and systemic therapy and surgical therapy use went from 37.3% to 44.1% (P < .001) and 67.7% to 67.5% (P = .79), respectively. Radiotherapy utilization decreased most in genitourinary, HN, and CNS cases with relative declines of -42.5% (-12.4% absolute decrease, P < .001), -10.3% (-6.1%, P < .001), and -9.6% (-3.2%, P = .001), respectively. Radiotherapy utilization increased in gastrointestinal (+0.6% absolute increase, P < .001), musculoskeletal (+1.0%, P = .002), skin (+0.7%, P = .002), and thoracic (+0.1%, P = .46) malignancies. In patients receiving EBRT, the mean number of fractions delivered per patient declined from 28.7 to 25.2 (P < .001); declines were evident in all disease sites but CNS.

CONCLUSION: We found a steady decrease in the percent of patients receiving radiotherapy in their first course of treatment, and a global decline in the mean number of fractions delivered per patient receiving EBRT, compared with an increase in systemic therapy and stable surgery utilization. These results illustrate the changing use of radiotherapy and fractionation during first-line therapy in contemporary US cancer care.