Improved Accuracy of Computerized Tomography Based Clinical Staging in Low Stage Nonseminomatous Germ Cell Cancer Using Size Criteria of Retroperitoneal Lymph Nodes

Purpose: We evaluated the significance of retroperitoneal lymph nodes detected by computerized tomography (CT) of low stage nonseminomatous germ cell tumor patients. Materials and Methods: A blind retrospective review of 143 CTs of low stage nonseminomatous germ cell tumor revealed pathological stage A disease on 89 (62.2 percent) and pathological stage B disease on 54 (37.8 percent). A multivariate logistic regression model was used to evaluate the relationships between diameter of the retroperitoneal nodes detected in these CTs and pathological stage. Results: Based on this model, as the diameter of the nodes increased within a 0 to 25 mm. range, the likelihood of pathological stage B disease increased in a continuous fashion. Using a 3 mm. threshold to define nonmetastatic nodes the sensitivity and negative predictive value of CT based staging was 90 percent. Conclusions: This measurement scheme improves the accuracy of staging compared to conventional methods.