Factors associated with radiological misstaging of pancreatic ductal adenocarcinoma: a retrospective observational study

Purpose Accurate staging of disease is vital in determining appropriate care for patients with pancreatic ductal adenocarcinoma (PDAC). It has been shown that the quality of scans and the experience of a radiologist can impact computed tomography (CT) based assessment of disease. The aim of the current study was to evaluate the impact of the rereading of outside hospital (OH) CT by an expert radiologist and a repeat pancreatic protocol CT (PPCT) on staging of disease. Methods Patients evaluated at the our institute's pancreatic multidisciplinary clinic (2006 to 2014) with OH scan and repeat PPCT performed within 30 days were included. In-house radiologists staged disease using OH scans and repeat PPCT, and factors associated with misstaging were determined. Results The study included 100 patients, with a median time between OH scan and PPCT of 19 days (IQR: 13 – 23 days.) Stage migration was mostly accounted for by upstaging of disease (58.8% to 83.3%) in all comparison groups. When OH scans were rereviewed, 21.5% of the misstaging was due to missed metastases, however, when rereads were compared to the PPCT, occult metastases accounted for the majority of misstaged patients (62.5%). Potential factors associated with misstaging were primarily related to imaging technique. Conclusion A repeat PPCT results in increased detection of metastatic disease that rereviews of OH scans may otherwise miss. Accessible insurance coverage for repeat PPCT imaging even within 30 days of an OH scan could help optimize delivery of care and alleviate burdens associated with misstaging.