Comparison of Treatment Response Assessment for Stage IV NSCLC after Chemotherapy Between Non-Contrast and Contrast-Enhanced CT Scans of The Chest
Keywords:Non-contrast chest CT, Non-small cell lung cancer, Chemotherapy, Treatment response assessment
Objective: To evaluate whether non-contrast chest CT (NCCT) images are as reliable as contrastenhanced chest CT (CECT) images for the assessment of treatment response after chemotherapy in patients with stage IV non-small cell lung cancer (NSCLC).
Material and A total of 87 patients with the stage IV NSCLC underwent chest CT for the assessment of tumor response after chemotherapy at Thammasat University Hospital between January 2014 and December 2016. Tumor response after chemotherapy of each patient was evaluated by using follow-up NCCT and CECT in comparison with the baseline CECT before chemotherapy based on RECIST criteria (version 1.1).
Result: Eighty-six (99%) of the 87 patients had the same treatment response results from both imaging sets. Only one case (1%) had a different result that was caused by a minimal difference in the target lesions size. However, there was no change in the management of this patient. The statistical analysis showed almost perfect agreement between using follow-up NCCT and CECT in the assessment of tumor response after chemotherapy with a kappa value of 0.982 (95% confidence interval; 0.947, 1.017). There was no statistically significant difference in the target lesions size in the follow-up study obtained by NCCT and CECT (P - value = 0.350).
Conclusion: Using follow-up NCCT in comparison with the baseline CECT provides almost perfect agreement with follow-up CECT in the assessment of the tumor response after chemotherapy. Therefore, NCCT can be a reasonable alternative to CECT for follow-up tumor response after chemotherapy especially in a patient with impaired renal function.