Clinical value of FDG-PET for carcinoma of the papilla of Vater

Objectives The purpose of this study was to evaluate the diagnostic performance of FDG-PET in staging and restaging for carcinoma of the papilla of Vater (CPV).

Methods We conducted a retrospective review of 36 scans in 27 patients with histologically-proven CPV who had undergone FDG-PET scans between January 2005 and December 2009. The histological type was adenocarcinoma in all cases. The purpose of scanning was for initial staging before treatment in 25 scans, and for post-therapeutic restaging in 11scans. For staging, we evaluated the diagnostic performance of FDG-PET to detect primary tumor, lymph nodes metastasis, and distant metastasis. For restaging, diagnostic performance of FDG-PET for detecting metastatic foci and influence on therapeutic management were assessed. Final diagnoses were obtained histologically or by clinical follow-up for at least 6 months.

Results For staging, the primary tumor was depicted in 20 of 25 cases (80%). The sensitivity, specificity, and accuracy of FDG-PET for detecting nodal metastasis were 25%, 88%, and 68%, respectively, and those for detecting distant metastasis were 50%, 100%, and 92%, respectively. In post-therapeutic evaluation, there were 5 cases with positive nodal metastasis and 2 cases with liver metastasis. The patient-based sensitivity and specificity were 80% and 100%, respectively. In spite of high diagnostic ability, PET findings affected a therapeutic plan in 2 cases (18%) in this population.

Conclusions Although the sensitivity of FDG-PET for primary tumor and recurrent foci was reasonably high, that for lymph node metastasis was low in patients with CPV. In addition, prevalence with clinical impact by FDG-PET was also limited