Does GRASP affect DCE-MRI for assessing response to neoadjuvant chemotherapy in patients with esophageal cancer?

Purpose To compare the value of two dynamic contrast-enhanced Magnetic Resonance Images (DCE-MRI) reconstruction approaches, namely golden-angle radial sparse parallel (GRASP) and view-sharing with golden-angle radial profile (VS-GR) reconstruction, and explore their values in assessing response to neoadjuvant chemotherapy (nCT) in esophageal cancer (EC). Methods The study prospectively enrolled EC patients receiving nCT before surgery. DCE-MRI scanning was performed after nCT and within 1 week before surgery. Chemotherapy response was assessed according to Tumor Regression Grade (TRG), and patients were stratified into a responsive group (TRG1+2) and a non-responsive group (TRG3+4+5). Wilcoxon test was utilized for comparing GRASP and VS-GR reconstruction, and Kruskal-Wallis and Mann-Whitney test was performed for each parameter to assess response, and Spearman test was performed for analyzing correlation between parameters and TRGs, as well as responder and non-responder. Results Among the 64 patients included in this cohort (52 male, 12 female; average age of 59.1±7.9 years), 4 patients showed TRG1, 4 patients were TRG2, 7 patients were TRG3, 11 patients were TRG4, and 38 patients were TRG5. They were stratified into 8 responders and 56 non-responders. A total of 15 parameters were calculated from each tumor. With VSGR, 10/15 parameters significantly correlated with TRG and response groups. Of these, only AUCmax showed moderate correlation with TRG, 7 showed low correlation and 2 showed negligible correlation with TRG. 8 showed low correlation and 2 showed negligible correlation with response groups. With GRASP, 13/15 parameters significantly correlated with TRG and response groups. Of these, 10 showed low correlation and 3 showed negligible correlation with TRG. 11 showed low correlation and 2 showed negligible correlation with TRG. Conclusion In patients with esophageal cancer on neoadjuvant chemotherapy, several parameters can differentiate responders from non-responders, using both GRASP and VS-GR techniques. GRASP may be able to better differentiate these two groups compared to VS-GR.