Contrast-enhanced Ultrasound for Follow-up After Radiofrequency Ablation of Kidney Lesions

Contrast-enhanced Ultrasound for Follow-up After Radiofrequency Ablation of Renal Lesions: a Prospective, Blinded Study

Radiofrequency ablation (RFA) is an increasingly popular therapy option for treating small kidney cancer, especially for patients who are not ideal candidates for traditional surgery. Currently, follow-up after this procedure involves the patient having several CT scans (or MRI scans in some cases) over time to monitor for possible cancer recurrence. However, there are risks associated with the radiation exposure from CT scans and other risks, such as adverse events from the contrast media used in these scans. This study will therefore investigate whether a different technique, contrast-enhanced ultrasound (CEUS), can be an effective tool for follow-up monitoring of kidney cancer patients who have undergone RFA by comparing the results of their standard follow-up CT scans (or MRIs if applicable) with the results of CEUS. If CEUS is found to be just as effective as CT scans or MRIs in detecting kidney cancer recurrence, this technique could potentially become the new standard of care for follow-up.

Contrast-enhanced ultrasounds of the kidney will be performed within 7 days of routine CTs or MRIs at 3, 6, 12, 18, and 24 months post-radiofrequency ablation, with Perflutren Lipid Microsphere Injectible Suspension ('Definity') as the contrast agent.

The accuracy of contrast-enhanced ultrasound in monitoring renal lesions post-radiofrequency ablation will be assessed through sensitivity, specificity, and positive predictive value of CEUS for tumour recurrence and by comparing to the standard CT/ MRI.

The accuracy of contrast-enhanced ultrasound in monitoring renal lesions post-radiofrequency ablation will be assessed through sensitivity, specificity, and positive predictive value of CEUS for tumour recurrence and by comparing to the standard CT/ MRI.

The accuracy of contrast-enhanced ultrasound in monitoring renal lesions post-radiofrequency ablation will be assessed through sensitivity, specificity, and positive predictive value of CEUS for tumour recurrence and by comparing to the standard CT/ MRI.

The accuracy of contrast-enhanced ultrasound in monitoring renal lesions post-radiofrequency ablation will be assessed through sensitivity, specificity, and positive predictive value of CEUS for tumour recurrence and by comparing to the standard CT/ MRI.

The accuracy of contrast-enhanced ultrasound in monitoring renal lesions post-radiofrequency ablation will be assessed through sensitivity, specificity, and positive predictive value of CEUS for tumour recurrence and by comparing to the standard CT/ MRI.

Inclusion Criteria: at least 18 years of age and capable of giving informed consent patient undergoing CT of MRI for monitoring of renal lesions after radiofrequency ablation Exclusion Criteria: pregnant patients patients with allergies to iodinated contrast agents patients with pulmonary hypertension, right-to-left cardiac shunts, or unstable cardiopulmonary disease (these are absolute or relative contraindications to the use of the ultrasound contrast agent, perflutren lipid microsphere)