Dynamic contrast-enhanced MRI for response evaluation of non-small cell lung cancer in therapy with epidermal growth factor receptor tyrosine kinase inhibitors: a pilot study

Background It is important to identify candidates who would benefit from target agent chemotherapy in advanced NSCLC patients. The purpose of this study is to evaluate the feasibility of DCE-MRI for early response evaluation in epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) treatment in patients with NSCLC. Methods Seven patients were prospectively enrolled who have pathologically-proven NSCLC with EGFR mutations or at least 2 of the following factors; adenocarcinoma, female, or never-smokers. Patients were treated with gefitinib or erlotinib and the start of chemotherapy was denoted day 0. DCE-MRI was performed at day-1, day+7, and day+28. Longitudinal changes of perfusion parameters were quantified and compared to Response Evaluation Criteria in Solid Tumors (RECIST) results. Results Quantitative perfusion parameters; Ktrans, ve and vp of the lung cancer showed a significant decrease at day+7 (P=0.016), but no further significant decrease between day+7 and day+28 (P>0.05). Semiquantitative markers for tumor enhancement curve pattern; EA (enhancement amplitude), MS (maximum slope), and AUC (area under the curve) also showed a significant decrease at day+7 (P=0.016, 0.031, and 0.016, respectively), but no further significant decrease between day+7 and day+28 (P>0.05). When RECIST applied, all patient was in the stable disease at day+7 and three patients showed partial response (PR) at day+28. All seven patients showed PR by the 3-month follow-up. Conclusions Perfusion parameters may be used as an early non-invasive imaging biomarker for the response evaluation of target agent treatment in NSCLC.