Computerized tomography: how accurate for abdominal staging of testis tumors?

To assess the ability of computerized tomography to predict correctly the presence of retroperitoneal lymphadenopathy, a prospective study was performed on 30 patients with all stages of testis tumor. All patients underwent a computerized tomography scan within 1 week before retroperitoneal lymphadenectomy and the results then were correlated with gross and histologic findings. The computerized tomography scan suggested retroperitoneal lymphadenopathy in 14 patients, in 1 of whom no retroperitoneal lymphadenopathy was found at exploration (false positive, 7 per cent). The sensitivity (computerized tomography negative divided by true positive) was 90 per cent, for an over-all accuracy of 73 per cent. Most importantly, however, 7 of the 16 computerized tomography scans (44 per cent) interpreted as normal proved to be false negative. Of these 7 scans 5 were in patients with tumors classified as stage B2 or greater. We conclude that the computerized tomography scan, when positive, is highly likely to detect metastatic nodal involvement. However, the false negative rate, even in patients with tumor-filled lymph nodes 2 to 3 cm. in diameter, limits the reliability of a negative computerized tomography scan to exclude metastases. Technological improvements are needed to refine the technique and, thus, to reduce the false negative rate.