Overuse of diagnostic brain imaging among patients with stage IA non–small cell lung cancer

Background: Among patients diagnosed with stage IA non–small cell lung cancer (NSCLC), the incidence of occult brain metastasis is low, and several professional societies recommend against brain imaging for staging purposes. The goal of this study was to characterize the use of brain imaging among Medicare patients diagnosed with stage IA NSCLC. Methods: Using data from linked SEER-Medicare claims, we identified patients diagnosed with AJCC 8th edition stage IA NSCLC in 2004 through 2013. Patients were classified as having received brain imaging if they underwent head CT or brain MRI from 1 month before to 3 months after diagnosis. We identified factors associated with receipt of brain imaging using multivariable logistic regression. Results: Among 13,809 patients with stage IA NSCLC, 3,417 (25%) underwent brain imaging at time of diagnosis. The rate of brain imaging increased over time, from 23.5% in 2004 to 28.7% in 2013 (P5.0006). There was significant variation in the use of brain imaging across hospital service areas, with rates ranging from 0% to 64.0%. Factors associated with a greater likelihood of brain imaging included older age (odds ratios [ORs] of 1.16 for 70–74 years, 1.13 for 75–79 years, 1.31 for 80–84 years, and 1.46 for $85 years compared with 65–69 years; all P,.05), female sex (OR, 1.09; P,.05), black race (OR 1.23; P,.05), larger tumor size (ORs of 1.23 for 11–20 mm and 1.28 for 21–30 mm tumors vs 1–10 mm tumors; all P,.05), and higher modified Charlson-Deyo comorbidity score (OR, 1.28 for score .1 vs score of 0; P,.05). Conclusions: Roughly 1 in 4 patients with stage IA NSCLC received brain imaging at the time of diagnosis despite national recommendations against the practice. Although several patient factors are associated with receipt of brain imaging, there is significant geographic variation across the United States. Closer adherence to clinical guidelines is likely to result in more cost-effective care.