Non-small cell lung cancer brain metastasis screening in the era of positron emission tomography-CT staging: Current practice and outcomes.

INTRODUCTION: Several clinical guidelines indicate that brain metastasis screening (BMS) should be guided by disease stage in non-small cell lung cancer (NSCLC). We estimate that screening is performed more broadly in practice, and patients undergo brain imaging at considerable cost with questionable benefit. Our aim was to quantify the use and detection rate of BMS in a contemporary cohort staged with 18 F-fluorodeoxyglucose positron emission tomography/computed tomography (PET-CT).

METHODS: We conducted a retrospective review of prospectively collected data from three major lung cancer referral centres in Brisbane between January 2011 and December 2015. Patients included had a new diagnosis of NSCLC and had undergone a PET-CT to stage extra-cranial disease. BMS was defined as dedicated brain imaging with contrast-enhanced computed tomography (CE-CT) or magnetic resonance (MR), in the absence of clinically apparent neurological deficits.

RESULTS: A total of 1751 eligible cases were identified and of these 718 (41%) underwent BMS. The majority had CE-CT imaging (n = 703). Asymptomatic brain metastases (BM) were detected in 18 patients (2.5%). Of these patients, 12 had concurrent non-brain metastases. Only six patients (0.8%) had BM alone. The rate of detection increased with N-stage (P = 0.02) and overall stage (P < 0.001). It was 0.5%, 1%, 1.6% and 7.3% for stage I, II, III and IV respectively. The overall screening rate increased with T-stage (P = 0.001), N-Stage (P < 0.001) and overall stage (P < 0.001).

CONCLUSIONS: Non-small cell lung cancer BMS practices remain at odds with published guidelines. The low number of occult BMs detected supports the existing international recommendations. Rationalising BMS would minimise the burden on patients and the health care system.