The value of pre-operative computed tomography scanning for the assessment of lymph node status in patients with colon cancer

AimOur aim was to determine the value of a pre-operative computed tomography (CT) scan for the assessment of lymph node status in patients diagnosed with colon cancer by comparing radiological N-stage to histopathological N-stage.Patients and methodsWe performed a retrospective cohort study at the Sint Lucas Andreas Hospital in Amsterdam, the Netherlands. Between 2008 and 2010, two radiologists independently reviewed all pre-operative CT scans of patients diagnosed with colon cancer. The scans were examined for signs of regional lymphatic spread (N+), defined as lymph nodes exceeding 1 cm, clusters of ≥3 lymph nodes or a combination of the two. The results were compared with the histopathological N-stage. Inter-observer agreement, positive predictive value (PVV), negative predictive value (NPV), sensitivity, specificity, and accuracy were calculated.ResultsWe included 106 patients in our study. PVV, NPV, sensitivity, specificity, and accuracy of detecting regional lymph nodes metastases were 47%, 66%, 71%, 41% and 54%, respectively. Inter-observer agreement was 74.5% (к = 0.48).ConclusionAlthough our study group was relatively large and newer techniques were used in comparison to previous studies, our results demonstrated that the value of a pre-operative CT scan for the assessment of regional lymph nodes remained poor and unreliable. Therefore we question if a radiologist should assess regional lymph nodes on a pre-operative CT scan in colon cancer. Before treatment decisions are made on the appearance of lymph nodes in colon cancer patients, its diagnostic accuracy needs strong improvement.