Objective: The aim of this study was to compare the diagnostic value of (18)F-FDG PET/CT with contrast CT for regional lymph node metastasis of colorectal cancer.
Methods: Imaging results of 40 patients with colorectal cancer were retrospectively reviewed, and all the patients underwent both abdomen contrast CT and (18)F-FDG PET/CT imaging. Final diagnosis was made by histopathology.
Results: 20 colorectal cancer patients were verified with lymph node metastasis while the other 20 patients were absent. Finally, (18)F-FDG PET/CT produced 4 false-positive patients and 3 false-negative patients. (18)F-FDG PET/CT displayed sensitivity 85.0% (17/20), specificity 80.0% (16/20), positive predictive value 81.0% (17/21), negative predictive value 84.2% (16/19) and accuracy 82.5% (33/40) in the diagnosis of lymph node metastasis. Contrast CT produced 5 false-positive patients and 8 false-negative patients. Contrast CT had the sensitivity 60.0% (12/20), specificity 75.0% (15/20) , positive predictive value 70.6% (12/17), negative predictive value 65.2% (15/23) and accuracy 67.5% (27/40). Sensitivity and specificity of PET/CT was better than of contrast CT, but no statistically significant difference between PET/CT and contrast CT (P = 0.478, P = 0.893; P = 0.344. Fisher's exact test and McNemar test).
Conclusion: Sensitivity and specificity of PET/CT was better than of contrast CT, but no statistically significant difference. Clinical works also need to select the appropriate inspection methods based on the patient's situation.