(P085) Trends in Stereotactic Body Radiation Therapy for Stage I Small Cell Lung Cancer

Abstract

We aimed to report trends in stereotactic body radiation therapy (SBRT) utilization, dose prescriptions, and chemotherapy administration for stage I small cell lung cancer (SCLC) in the United States. The National Cancer Data Base (NCDB) was used to identify patients with clinical stage I (cT1-2 N0) SCLC treated with SBRT between 2004 and 2013. Trends in SBRT use and dose prescription were analyzed over time. Multivariable logistic regression was used to determine factors associated with the administration of chemotherapy with SBRT. The Kaplan-Meier method was used to estimate overall survival. A total of 9,265 patients with clinical stage I SCLC were examined for initial treatment allocation. Of these patients, the 285 treated with SBRT were the subject of the primary analysis. The median age was 75 years. SBRT utilization has steadily increased from 2004 (0.4% of all stage I patients diagnosed that year) to 2013 (6.4%). Definitive surgical management also increased from 14.9% of all patients in 2004 to 28.5% in 2013. The median SBRT biologically effective dose (BED10) was 112.5 Gy (range, 72 – 290) and only 33 out of 285 (11.6%) received a BED10 < 100 Gy. Nearly half of all patients (130/285, 45.6%) received chemotherapy. On multivariable logistic regression, only age < 75 vs. ≥ 75 years (OR 6.04, 95% CI 3.20 – 11.44, p < 0.001) and year of diagnosis 2004-2008 vs. 2009-2013 (OR 2.58, 95% CI 1.27 – 5.26, p = 0.009) were predictive of chemotherapy use with SBRT. After median follow up of 45 months, the median survival was 23.5 months. Our findings suggest that SBRT utilization for SCLC has increased between 2004 and 2013, highlighting the need for additional research to validate the feasibility of this management approach for inoperable patients with cT1-2 N0 SCLC.