Oncologic imaging. Staging and follow-up of renal and adrenal carcinoma.

Computed tomography (CT) has emerged from the 1980s to play a dominant role in the pretreatment staging of renal and adrenal carcinomas. For detection, definition (staging), and determination of resectability or recurrence, CT with intravenous contrast enhancement, and more recently, magnetic resonance imaging (MRI) with gadolinium-DTPA, may be the only cross-sectional imaging studies required before institution of appropriate therapy. Carcinoma of the kidney is frequently diagnosed by serendipity or detected on incidental ultrasound or CT examinations. Real-time ultrasound and color flow Doppler offer unique information on tumor vascularity and major venous vascular involvement. Positive predictive values of 96% can be achieved for the diagnosis of renal cell carcinoma using contrast-enhanced CT scanning. For follow-up CT and MRI are the best imaging techniques for evaluation of the retroperitoneum. MRI may distinguish tumor recurrence from fibrosis in selected cases. Because primary neoplasms of the adrenal gland are rare and often exceed 10 cm at the time of initial diagnosis, the functional nature (endocrine) of adrenal carcinoma may be part of the clinical presentation. Because initial stage is critical to survival and extent of surgical therapy, a knowledge of tumor classification is essential to the optimal diagnostic evaluation. Newer imaging tests, CT and MRI, have superseded conventional urography, ultrasound, and radionuclide studies for the diagnosis and staging of adrenal cancer. Early diagnosis and low stage at presentation are critical to survival in patients with adrenal carcinoma. The current concepts for pretreatment imaging evaluation and the role of CT, MRI, and ultrasound are outlined. An oncologic imaging approach based on tumor staging and classification for patients with real or suspected renal cell carcinoma and adrenal carcinoma is essential to optimal patient care.