Role of intraoperative US in the decision for radical or partial nephrectomy.

PURPOSE To investigate the effect of intraoperative ultrasonographic (US) findings on the decision for the type of nephrectomy to be performed in patients who had renal tumors that were preoperatively evaluated by using magnetic resonance (MR) imaging, with pathologic results as the reference standard. MATERIALS AND METHODS The institutional review board approved the study protocol, and informed consent was obtained. Between June 2008 and September 2009, 44 patients (25 men, 19 women; mean age, 56.6 years; range, 28-76 years) with 46 renal tumors were prospectively assessed by using intraoperative US examinations to demonstrate tumor relationship with the nontumoral intact parenchyma. Findings at preoperative MR examinations were retrospectively evaluated by two radiologists to determine the type of surgery that would be recommended. The reference standard was results of pathologist's review of gross specimens and postoperative reports. The observers assigned their decisions as follows: score group 1, radical nephrectomy should be (should have been) performed; score group 2, partial nephrectomy can be (could have been) attempted; and score group 3, partial nephrectomy should be (should have been) performed. RESULTS Radical nephrectomy was performed in 36 lesions. In all cases, the intraoperative US observer and the pathologist were concordant in the decision that radical nephrectomy versus partial nephrectomy could or should have been performed. MR observers 1 and 2 overcalled the need for radical nephrectomy in seven and four cases, respectively. Compared with pathologic results, the overall correlation of intraoperative US was 0.991, and the correlation for MR observer 1 was 0.786 and that for MR observer 2 was 0.731. CONCLUSION Intraoperative US can be suggested as a valuable examination method in patients with tumors at a central location with suspicious renal sinus extension demonstrated by using MR imaging. The close cooperation of urologist and radiologist in renal tumor work-up could reduce performance of unnecessary radical nephrectomy.