Additional Value of Integrated F-FDG PET/MRI for Evaluating Biliary Tract Cancer: Comparison with Contrast-Enhanced CT.

OBJECTIVE

To evaluate the value of F-fluorodeoxyglucose PET/MRI added to contrast-enhanced CT (CECT) in initial staging, assessment of resectability, and postoperative follow-up of biliary tract cancer.

MATERIALS AND METHODS

This retrospective study included 100 patients (initial workup [n = 65] and postoperative follow-up [n = 35]) who had undergone PET/MRI and CECT for bile duct or gallbladder lesions between January 2013 and March 2020. Two radiologists independently reviewed the CECT imaging set and CECT plus PET/MRI set to determine the likelihood of malignancy, local and overall resectability, and distant metastasis in the initial workup group, and local recurrence and distant metastasis in the follow-up group. Diagnostic performances of the two imaging sets were compared using clinical-surgical-pathologic findings as standards of reference.

RESULTS

The diagnostic performance of CECT significantly improved after the addition of PET/MRI for liver metastasis (area under the receiver operating characteristic curve [A]: 0.77 vs. 0.91 [ = 0.027] for reviewer 1; 0.76 vs. 0.92 [ = 0.021] for reviewer 2), lymph node metastasis (0.73 vs. 0.92 [ = 0.004]; 0.81 vs. 0.92 [ = 0.023]), and overall resectability (0.79 vs. 0.92 [ = 0.007]; 0.82 vs. 0.94 [ = 0.021]) in the initial workup group. In the follow-up group, the diagnostic performance of CECT plus PET/MRI was significantly higher than that of CECT imaging for local recurrence (0.81 vs. 1.00 [ = 0.029]; 0.82 vs. 0.94 [ = 0.045]).

CONCLUSION

PET/MRI may add value to CECT in patients with biliary tract cancer both in the initial workup for staging and determination of overall resectability and in follow-up for local recurrence.