Testicular tumors: oncologic imaging and diagnosis.

The extreme radiosensitivity of testicular seminomas plus recent advances in chemotherapy for nonseminomatous tumors and for advanced seminomas have made long term survival possible in the large majority of patients with testis cancer. Since choice of therapy is determined by tumor histology and extent of disease, accurate clinical staging is critical. Computed tomography (CT) of the abdomen and chest is the imaging procedure of choice for staging testis cancer. Clinical staging accuracy of 80 to 90% can be achieved using CT in combination with radioimmunoassays for beta-HCG and AFP. Ultrasonography (US), while less sensitive and specific than CT for determining nodal status, may be useful in thin patients with sparse retroperitoneal fat; in addition US may play an important role in detecting occult testicular neoplasms and in assessing primary tumor extent within the scrotum. Lymphangiography should be reserved for Stage I patients in whom elective treatment of the retroperitoneum is not planned. Follow-up should include serial radioimmunoassays for serum AFP and beta-HCG and periodic CT examinations of the abdomen and chest. Technical improvements in CT scanners and further experience with the use of tumor markers should help refine our ability to stage and manage patients with testicular tumors. In addition, nuclear magnetic resonance (NMR) imaging and radionuclide imaging following injection of radioactively labelled antibodies to AFP and beta-HCG are new techniques which offer great promise for the future.