Intraductal papillary mucinous neoplasm of the pancreas: A comparison of the likelihood of invasiveness between 18F-FDG PET/CT and contrast enhanced MDCT findings

Objectives To evaluate the capability of 18F-FDG PET/CT (PET/CT) in determining the likelihood of invasiveness of intraductal papillary mucinous neoplasm (IPMN) of the pancreas.

Methods Twenty-four patients with IPMN (non-invasive, 15 [benign, 8; in situ carcinoma, 7]; invasive carcinoma, 9) proved by a pathologic examination were retrospectively evaluated. They underwent surgery after both PET/CT and contrast enhanced MDCT (CE-CT) were performed. Invasiveness was suspected when increased FDG uptake (SUVmax ≥ 2.5) was observed with PET/CT, and when a solid mass or dilated main pancreatic duct (MPD; ≥ 10-mm diameter) was observed with CE-CT. The results were compared between non-invasive and invasive IPMNs using Student’s t-test.

Results SUVmax, diameters of cystic tumor, and diameters of MPD of the non-invasive and invasive IPMNs were 1.9 ± 0.6 vs. 5.7 ± 3.3 (p < .05), 30.2 ± 9.9 vs. 34.4 ± 8.1 (p = 0.28), and 5.6 ± 2.6 vs. 8.7 ± 3.8 (p = 0.06), respectively. Solid masses were observed in 0/15 and 5/9 patients with non-invasive and invasive carcinomas, respectively. The sensitivity, specificity, and accuracy for detecting invasiveness were 1, 0.93, and 0.96 with PET/CT and 0.89, 0.94, and 0.96 with CE-CT, respectively.

Conclusions PET/CT provides useful information regarding the likelihood of invasiveness of IPMN, which is almost equivalent to those provided by CE-CT.