Is renal salvage feasible in unilateral Wilms' tumor? Proposed computed tomographic criteria and their relation to surgicopathologic findings

The ability of computed tomographic (CT) criteria to predict the potential for resection with renal salvage in unilateral Wilms' tumor was evaluated retrospectively in 10 children given preoperative treatment for initially inoperable disease. Criteria were (a) tumor involving only one pole and occupying less than one-third of the kidney, (b) functioning kidney, (c) no invasion of collecting system or renal vein, and (d) clear margins between tumor, kidney, and surrounding structures. Review of preoperative CT scans correctly predicted nonsalvageability (as assessed by surgicopathologic findings) in seven cases. Sufficient pathologic data were lacking to confirm positive CT predictors in one case. One patient was rated resectable with salvage on surgicopathologic review, but not by CT criteria, and in one case, a prediction could not be made. The potential for renal salvage may be greater in samples with smaller initial tumor size, and addition of other imaging modalities might enhance the accuracy of prediction. Further studies are needed to assess the feasibility of prospective trials evaluating the risks and benefits of partial nephrectomy in unilateral Wilms' tumor.