Sequential CT Findings in Patients With Non-small-cell Lung Cancer Receiving Nivolumab.

Background: Nivolumab is a novel immunotherapy that was recently approved for treatment of advanced non-small-cell lung cancer (NSCLC). Patients treated with checkpoint inhibitors may show variable computed tomography (CT) features on follow-up imaging, and it is unclear how reliable conventional response criteria are to determine patient management and outcomes. We report the spectrum of sequential CT findings in patients with advanced stage lung cancer who received nivolumab in an effort to better inform appropriate imaging strategies.

Materials And Methods: We identified all patients at our institution with advanced NSCLC who received nivolumab. Pre- and posttreatment CT scans were reviewed and categorized based on radiographic response to therapy. Demographic data as well as survival data were recorded.

Results: There were 34 patients with advanced NSCLC who received nivolumab with sufficient follow-up data. Nineteen patients were classified as responders to treatment; 6 (32%) of 19 showed improvement on their initial follow-up CT and had an average survival of 11.2 months, whereas 13 (68%) of 19 responders initially had stable or progressive disease on CT with an average survival of 11.6 months. Fifteen patients were classified as nonresponders to treatment with an average survival of 3.4 months.

Conclusion: Novel immunotherapies such as nivolumab mechanistically differ from conventional chemotherapy. Some patients have improved survival despite initial radiographic progression of disease. Our findings underscore the heterogeneous radiographic appearance at follow-up CT in patients with lung cancer who ultimately respond to nivolumab.