Objectives: We investigated the reliability of local (T) and lymph node (N) category staging of renal adenocarcinoma by CT in patients submitted to radical nephrectomy.
Material and methods: The study comprised 109 patients with renal adenocarcinoma who had undergone radical nephrectomy from 1986-1994. The preoperative staging was done using dynamic CT. Clinical staging was based on the CT data and pathological staging was determined by the pathological findings. All patients had a transperitoneal radical nephrectomy. The sensitivity, specificity, positive (PPV) and negative predictive values (NPV) for tumors localized to the kidney, perirenal fat invasion, central venous and lymphatic invasion were analyzed.
Results: The overall sensitivity rate was 67%; the sensitivity and specificity rates were 77% and the PPV and NPV were 89.5% and 67%, respectively, for tumors localized to the kidney. The sensitivity rate was 66%, specificity was 76% and the PPV and NPV were 48.5% and 87.5%, respectively, for those with perirenal fat invasion. Tumors with venous spread showed a sensitivity of 90%, specificity of 92%, PPV 53% and NPV 99%. Concerning lymph node invasion, the sensitivity was 50%, specificity 96%, PPV 50%, NPV 96%.
Conclusions: CT has a very low sensitivity and specificity in detecting fat invasion, a very high sensitivity and specificity for venous invasion and a low sensitivity, but high specificity in detecting lymphatic spread.