MRI for Local Staging of Colon Cancer: Can MRI Become the Optimal Staging Modality for Patients With Colon Cancer?

OBJECTIVE: The purpose of this study was to evaluate the diagnostic performance of MRI for local staging of colon cancer. DESIGN: This was a retrospective study. SETTINGS: The study was conducted at the Maastricht University Medical Centre. PATIENTS: In total, 55 patients with biopsy-proven colon carcinoma were included. MAIN OUTCOME MEASURES: All of the patients underwent an MRI (1.5-tesla; T2 and diffusion-weighted imaging) of the abdomen and were retrospectively analyzed by 2 blinded, independent readers. Histopathology after resection was the reference standard. Both readers evaluated tumor characteristics, including invasion through bowel wall (T3/T4 tumors), invasion beyond bowel wall of >=5 mm and/or invasion of surrounding organs (T3cd/T4), serosal involvement, extramural vascular invasion, and malignant lymph nodes (N+). Interobserver agreement was compared using [kappa] statistics. RESULTS: MRI had a high sensitivity (72%–91%) and specificity (84%–89%) in detecting T3/T4 tumors (35/55) and a low sensitivity (43%–67%) and high specificity (75%–88%) in detecting T3cd/T4 tumors (15/55). For detecting serosal involvement and extramural vascular invasion, MRI had a high sensitivity and moderate specificity, as well as a moderate sensitivity and specificity in the detection of nodal involvement. Interobserver agreements were predominantly good; the more experienced reader achieved better results in the majority of these categories. LIMITATIONS: The study was limited by its retrospective nature and moderate number of inclusions. CONCLUSIONS: MRI has a good sensitivity for tumor invasion through the bowel wall, extramural vascular invasion, and serosal involvement. In addition, together with its superior liver imaging, MRI might become the optimal staging modality for colon cancer. However, more research is needed to confirm this.