Utility of PET-CT versus CT in staging colorectal cancer

Introduction: Colorectal cancer ranks third in incidence in Mexico and the world. The stage is one of the main prognostic factors. Due to the high percentage of cases with metastatic disease at diagnosis in Mexico, the correct choice of imaging studies is essential. Objective: Determine the usefulness of PET-CT with 18F-FDG vs. CT, in staging. Methods: Retrospective study. Patients with CRC and PET-CT and CT for staging, in a private hospital in Mexico were included. Demographic data, primary tumor site, histology, were collected, and primary and secondary lesions and their characteristics were recorded by PET-CT and CT. Results: 15 patients were included. 60% were men, the median age was 64 years. 73.3% developed in the left colon and 100% were adenocarcinoma. The PET-CT identified 73.3% of the primary lesions and 66.7% of the regional lymph nodes. Also, 9 cases with metastatic disease. Thus, the N and M staging of 8 and 4 patients, respectively, changed. The SUVmax of the primary lesions was 8.39; finding a significant correlation with the laterality of the primary tumor. -Conclusion: PET-CT proved to be more efficient in detecting primary and secondary lesions versus CT.