Effects of Contrast-Enhanced Ultrasound of Indeterminate Renal Masses on Patient Clinical Management: Retrospective Analysis From 2 Institutions.

Objectives: To investigate the long-term impact of contrast-enhanced ultrasound (CEUS) on the treatment of patients with indeterminate renal masses.

Methods: In this retrospective study, consecutive charts of all patients receiving renal CEUS at 1 of 2 academic medical centers between January 1, 2014, and December 31, 2018, were reviewed. Patients were included in the study if they had documented chronic renal disease (estimated glomerular filtration rate < 60 mL/min/1.73 m ) or prior nephrectomy and received CEUS for a previously untreated renal mass.

Results: A total of 215 lesions in 157 patients were used for analysis. Contrast-enhanced ultrasound provided a final treatment recommendation in 71.6% of lesions (154 of 215). Of these 154 lesions, 7.8% (12 of 154) were lost to follow-up despite CEUS suggesting malignancy; 15.6% (24 of 154) went directly for surgical intervention, with malignancy confirmed by pathologic results in 87.5% (21 of 24) of these cases; and the remaining 76.6% (118 of 154) were deemed benign and required no additional follow-up. Of the 118 lesions diagnosed by CEUS as benign and requiring no follow-up, none showed evidence of later renal cell carcinoma development and, only 5.1% (6 of 118) of the total population was referred for further cross-sectional imaging of the mass in question. In 28.4% of all lesions (61 of 215), CEUS resulted in a recommendation for surveillance imaging at a 6- to 12-month interval, and less than 10% (6 of 61) of these underwent additional cross-sectional imaging within the recommended 6 months after CEUS.

Conclusions: These findings highlight the impact of CEUS on clinical treatment of indeterminate renal masses, including reducing the use of the potentially nephrotoxic contrast agents and providing a direct pathway to transplant.