Radiologic diagnosis and staging of renal and bladder cancer

There are increasing numbers of incidentally detected renal tumors and increasing interest in nephron-sparing and laparoscopic surgery. Delineation of the tumor and the relationships to vascular and collecting system structures has an important impact on surgical planning. CT and MRI are probably comparable for these purposes and have broadly equivalent staging accuracies. Imaging has a limited role in the evaluation of the majority of bladder tumors since most tumors are superficial and diagnosed at cystoscopy, at which time they are also resected and staged. However, imaging has an important role in more advanced tumors in delineating involvement of adjacent structures, where clinical staging is frequently inaccurate. MRI is probably superior to CT, although the capabilities of thin-section multidetector CT have not yet been fully explored. Limitations of both modalities include the inability to reliably differentiate tumor from post-biopsy/resection changes or radiation edema and inflammation. Assessments of nodal disease based on size have limitations. There are some indications that 3D evaluation of size and shape and dynamic contrast enhancement characteristics may improve accuracy. MR lymphography in the pelvis with ultrasmall iron oxide particles is under evaluation, and this technique shows promise in lymph node staging. © 2006 Elsevier Inc. All rights reserved.