Patterns of Care in Stereotactic Body Radiation Therapy Fractionation Schedules in Non-Small Cell Lung Cancer in the United States From 2004-2016

ABSTRACT

Stereotactic Body Radiation Therapy (SBRT) is considered standard of care for inoperable early stage non-small cell lung cancer (NSCLC) and is commonly delivered in 1-5 fractions. Single fraction SBRT is supported by randomized data demonstrating equivalent safety compared to fractionated approaches. The purpose of this study is to measure trends in the utilization of SBRT fractionation in NSCLC patients in the National Cancer Database (NCDB) from 2004-2016. The NCDB was queried for patients with cT1-T3N0M0 NSCLC who were treated with a known SBRT dosing schema during the study period (including 30-34 Gy/1 fraction, 54-60 Gy/3 fractions, 48-50 Gy/4 fractions, and 50-60 Gy/5 fractions). Adjusted logistic regression was used to assess the association of treatment year with the annual percentage of patients who received SBRT using 1, 3, 4, and 5 fractions. Average annual percentage changes (AAPC) were computed and compared to determine if a significant change (defined a priori as P < 0.01) occurred in the use of different fractionation schemes over time. Multivariable analysis was used to evaluate factors associated with receipt of single fraction SBRT. The analytic cohort consisted of 39,536 patients. Use of 3 fraction SBRT decreased from 72.6% in 2004 to 20.3% in 2016 (AAPC -10.6% per year, 95% CI [-12.1%, -9.1%], P < 0.001). During this interval, a corresponding increase in the use of 5 fraction SBRT also occurred, from 6.5% in 2004 to 53.7% in 2016 (AAPC +18.3% per year, 95% CI [+13.3%, +23.4%], P < 0.001). No significant change was observed in single fraction and 4 fraction SBRT utilization;< 1% of patients per year received single fraction SBRT in all but three years of the study with a 1.1% percent utilization rate in 2016. On logistic regression, cT2 patients were less likely to receive single fraction SBRT (Odds Ratio 0.592, 95% CI 0.414-0.846) while academic facility (Odds Ratio 5.821, 95% CI 4.331-7.823) and Charlson Deyo Score > 2 (Odds Ratio 1.447, 95% CI 1.038-2.017) were significantly associated with receipt of single fraction SBRT. Age, insurance, distance to treatment facility, and treatment year were not significantly associated with single fraction SBRT. Single fraction SBRT use remained scarce in the United States during 2004-2016, with no clear indication of increased utilization after 2014 when RTOG0915 was first reported. With prospective evidence that long-term toxicity, local control, and survival are similar to 3-4 fraction regimens, the application of single fraction SBRT in the clinic may warrant further interest in light of the recent COVID-19 pandemic and the implementation of the alternative payment model. [ABSTRACT FROM AUTHOR] Copyright of International Journal of Radiation Oncology, Biology, Physics is the property of Pergamon Press - An Imprint of Elsevier Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)