Feasibility of contrast-enhanced ultrasound as a screening tool for patients at high risk for kidney malignancies

This pilot study investigated the feasibility of contrast-enhanced ultrasound (CEUS) as a screening tool to identify kidney lesions in patients with rare genetic disorders predisposing them to kidney malignancies, aiming to reduce reliance on repeated computed tomography (CT) and magnetic resonance imaging (MRI) scans. Fifteen patients (29 kidneys) with von Hippel-Lindau (VHL), Birt-Hogg-Dubé (BHD) syndrome, or hereditary leiomyomatosis and renal cell carcinoma (HLRCC) underwent surveillance with B-mode ultrasound, CEUS, and CT/MRI. Three blind readers assessed the presence and malignancy of lesions, with results compared against clinically obtained CT/MRI as the gold standard. Inter-reader agreement and diagnostic accuracy were evaluated using kappa statistics, as well as sensitivity and specificity to the gold standard. CEUS demonstrated high inter-reader reliability (κ =1 for lesion detection and κ =0.66 for malignancy). Specificity was 100% (21/21) and sensitivity was 75% (6/8) for identifying kidneys with at least one lesion compared to the gold standard. Notably, none of the lesions missed by ultrasound were malignant. All malignant lesions identified by the MRI/CT were correctly detected [100% (3/3) sensitivity], though some lesions flagged by CEUS were found to be benign [88% (23/26) specificity]. CEUS demonstrates high inter-reader reliability and strong diagnostic performance in detecting kidney lesions among high-risk patients, achieving 100% (3/3) sensitivity for malignant lesions. These findings support CEUS as a promising adjunct screening tool that may reduce reliance on frequent cross-sectional imaging (CT/MRI) in patients predisposed to kidney malignancies. Further studies in larger cohorts are warranted to validate these results and define its role in routine surveillance.