Role of F18-FDG PET-CT imaging in differentiating benign and malignant pancreatic lesions and its comparison with CT/MRI/EUS

Objectives The current prospective study was aimed to examine the role of PET-CT in differentiating benign and malignant pancreatic lesions with or with out underlying chronic pancreatitis and compare its results with CT/MRI/EUS.

Methods An observational study was performed on 103 patients (male-75, female-28) with pancreatic mass lesions suspected of having carcinoma of pancreas with or with out underlying chronic pancreatitis. All patients underwent whole body FDG PET-CT scan for evaluation of pancreatic lesion. A diagnostic work up with CT, MRI and EUS was also done. Histopathology of pancreatic lesion served as reference standard to measure the sensitivity, specificity, PPV, NPV and accuracy of PET-CT.

Results Of 103 patients, 37(36%) were benign and 66(64%) were malignant. The sensitivity, specificity, PPV, NPV and accuracy of PET-CT in differentiating malignant from benign lesions were 94%, 70.2%, 85%, 86.7% and 86.2%. Comparatively, CT showed sensitivity, specificity, PPV, NPV and accuracy of 96%, 31%, 74%, 82% and 73.4%. The sensitivities of PET-CT and CT/EUS were comparable. The results showed a higher specificity and accuracy for PET-CT as compared to CT, MRI and EUS. The common causes of false positive results were inflammatory and granulomatous disease. False negative results were noted in pancreatic endocrine tumors.

Conclusions F18-FDG PET-CT achieves a comparably high diagnostic impact in differentiating pancreatic mass lesions with or with out underlying chronic pancreatitis. When compared with conventional imaging modalities, PET-CT has similar sensitivity but showed higher specificity and accuracy.