Whole Body MRI in the Staging of Esophageal Cancer - A Prospective Comparison with Whole Body <sup>18</sup>F-FDG PET-CT

<b><i>Background:</i></b> Positron emission tomography and computed tomography (PET-CT) is established in the staging of esophageal cancer. In this study, an MRI protocol was designed to emulate the anatomical (T1-weighed (T1W) and T2W imaging) and functional information (diffusion-weighted imaging) provided by PET-CT. <b><i>Methods:</i></b> In all, 49 patients with carcinoma of the esophagus underwent PET-CT and whole-body MRI (WBMRI). WBMRI was carried out using dedicated sequences tailored to detect metastatic disease at each area corresponding to the anatomical coverage of PET-CT. Nodal status was determined from histopathology and endoscopic ultrasound biopsy (EUS). <b><i>Results:</i></b> PET-CT and WBMRI identified the primary tumor in 46/49 (94%) and 48/49 (98%) patients, respectively. Nodal analysis in patients undergoing surgery (n = 18) yielded sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of 27, 100, 100, 47 and 56% for PET-CT, compared with 30, 100, 100, 53 and 61% for WBMRI. When nodal analysis included both surgical specimens and EUS criteria (n = 39), sensitivity, specificity, PPV, NPV and accuracy were 46, 91, 93, 40 and 59% for PET-CT compared with 59, 92, 94, 50 and 67% for WBMRI. Both imaging modalities identified distant metastases in 2 patients. <b><i>Conclusion:</i></b> WBMRI has similar accuracy to PET-CT in detecting the primary tumor, nodal deposits and for exclusion of systemic metastatic disease.