OA10.05 Which Is Better for TNM Stage Assessment Among Whole-Body MRI and PET/MRI at 1.5 Tesla and 3 Tesla and FDG-PET/CT in Non-Small Cell Lung Cancer?

Accurate tumor staging is essential for choosing the appropriate treatment strategy for non-small cell lung cancer (NSCLC) patients. In 1990s, positron emission tomography (PET) or PET combined with CT (PET/CT) using 2-[fluorine-18]-fluoro-2-deoxy-D-glucose (FDG) were suggested as useful for TNM stag evaluation in NSCLC patients in routine clinical practice. Since 2007, whole-body magnetic resonance imaging (MRI) with diffusion-weighted imaging (DWI) at 1.5T or 3T systems and PET/MRI have been continuously testing in this setting. Moreover, PET fused with MRI (PET/MRI) with FDG has been suggested as a new tool for TNM stage and postoperative recurrence evaluations since 2015. However, all PET/MRI has been generated by MRI at 3T MR system and not tested that at 1.5T system. No one reported direct comparisons for TNM staging capability among whole-body MRI and PET/MRI at 1.5T and 3T systems and PET/CT in NSCLC patients. We hypothesize that whole-body MRI and PET/MRI at 1.5T and 3T MR systems have better potential for TNM stage assessment than whole-body FDG-PET/CT in NSCLC patients. The purpose of this study was to prospectively and directly compare TNM stage classification capability among whole-body MRI and PET/MRI at 1.5 and 3T MR systems and PET/CT in NSCLC patients. 104 consecutive pathologically diagnosed NSCLC patients (62 men, 42 women; mean age 71 years) prospectively underwent whole-body MRI at 1.5T and 3T systems, integrated PET/CT, and surgical, pathological and/ or follow-up examinations. Final diagnoses of T, N and M factors and clinical stage in each patient were determined according to all examination results. Then, each factor and clinical stage were visually assessed on both whole-body MRIs, PET/MRIs and PET/CT with contrast-enhanced brain MRI. Kappa statistics were used to determine agreements for assessment of all factors and clinical stage with final diagnoses, and McNemar’s test was used to compare each diagnostic accuracy among all methods. On each factor and clinical stage assessments, agreements between all methods and final diagnosis were substantial or almost perfect (0.60