Routine contrast-enhanced CT is insufficient for TNM-staging of duodenal adenocarcinoma

PURPOSE: Adequate TNM-staging is important to determine prognosis and treatment planning of duodenal adenocarcinoma. Although current guidelines advise contrast-enhanced CT (CECT) for staging of duodenal adenocarcinoma, literature about diagnostic tests is sparse. METHODS: In this retrospective single-center cohort study, we analyzed the real life performance of routine CECT for TNM-staging and the assessment of resectability of duodenal adenocarcinoma. Intraoperative findings and pathological staging served as reference standard for resectability, T-, and N-staging. Biopsies, (18)FDG-PET-CT, and follow-up were used as the reference standard for M-staging. RESULTS: Fifty-two consecutive patients with duodenal adenocarcinoma were included, 26 patients underwent resection. Half of the tumors were isodense to normal duodenum on CECT. The tumor was initially missed in 7/52 patients (13%) on CECT. The correct T-stage was assigned with CECT in 14/26 patients (54%), N-stage in 11/26 (42%), and the M-stage in 42/52 (81%). T-stage was underestimated in (27%). The sensitivity for detecting lymph node metastases was only 24%, specificity was 78%. Seventeen percent of patients had indeterminate liver or lung lesions on CECT. Surgery with curative intent was started in 32 patients, but six patients (19%) could not be resected due to unexpected local invasion or metastases. CONCLUSION: Radiologists and clinicians have to be aware that routine CECT is insufficient for staging and determining resectability in patients with duodenal adenocarcinoma. CECT underestimates T-stage and N-stage, and M-stage is often unclear, resulting in futile surgery in 19% of patients. Alternative strategies are required to improve staging of duodenal adenocarcinoma. We propose to combine multiphase hypotonic duodenography CT with MRI.