Prognostic and predictive value of histogram analysis in patients with non-small cell lung cancer refractory to platinum treated by nivolumab: A multicentre retrospective study

Purpose: The aim of this study was to assess computed-tomography histogram analysis (CTHA) as prognostic and predictive factor in platinum-refractory non-small cell lung carcinoma (NSCLC) treated with immune checkpoint inhibitor Nivolumab.Method: One hundred and four patients were enrolled from 3 different centers. CT was performed using similar parameters among different scanners. CTHA was performed with the proprietary software TexRAD, which extracts histogram features at different spatial scale (spatial scale filters, SSF) producing 30 CTHA features per patients. Cross-validated Least Absolute Shrinkage and Selection Operator LASSO was used to select those features which were related to overall and progression-free survival (OS and PFS, respectively). High- and low-risk subgroups were identified using the best cutoff.Results: Median follow-up was 13.8 weeks. Median OS and PFS were 7.3 and 3 months, respectively. LASSO selected kurtosis obtained by SSF = 4 mm as the single feature related to OS, leading to an hazard ratio (HR) of 0.476 (95%CI 0.29-0.77). PFS was related with kurtosis SSF = 6 mm, with HR of 0.556 (95%CI 0.36-0.86).Conclusion: Despite its limitations, this study is the first which suggests that CTHA could play a role in stratifying prognosis and treatment response in patients with NSCLC treated with Nivolumab