Contrast‐enhanced ultrasound after successful cryoablation of benign and malignant renal tumours: how long does tumour enhancement persist?

Abstract

Introduction: To investigate how long successfully ablated tumours take to become completely avascular at CEUS after cryoablation. Methods: Ninety-five patients had percutaneous cryoablation of 103 renal tumours investigated at CEUS on post-operative day one. If the lesion was avascular, a contrast-CT/MR was scheduled six months after the procedure, while CEUS was repeated if the lesion still displayed enhancement, until the disappearance of intralesional vascularity. Technical success was defined when the tumour was covered completely by the ablation zone. Technique efficacy was assessed at six months of follow-up. Results: Technical efficacy was obtained for 101/103 cryoablations, 56% of which (57/101) were avascular on post-operative day one. After one week, two weeks, one month 83%, 91% and 100% of these 101 lesions, respectively, were avascular. Two tumours were unsuccessfully treated. They displayed persistent intralesional vascularity at CEUS one month after the procedure. Conclusions: After cryoablation, obtaining CEUS before one month may be misleading. When technical efficacy is obtained, disappearance of intralesional enhancement is observed within two weeks in the majority of cases (91%), but can persist until one month. Identification of tumour enhancement after one month may be concerning for residual viable tumour.

Role of Contrast-Enhanced Ultrasound (CEUS) in Native Kidney Pathology: Limits and Fields of Action

“…In accordance with the EAU guidelines [28], evaluation of ablative treatments of small kidney lesions requires a close monitoring of the ablated area, both to check for any complications and to assess the success of the procedure. CEUS has progressively taken a role in the follow-up, especially early after the procedure [29][30][31]. The treatment is considered successful if the lesion becomes completely avascular.…”

“…The treatment is considered successful if the lesion becomes completely avascular. This usually occurs early after radiofrequency and microwave ablation (Figure 5) [29,32], while it may take up to one month after cryoablation (Figure 6), requiring a tailored follow-up [30,31]. Therefore, an adequate knowledge of the type of ablative treatment allows a correct interpretation of the images, thus reducing the risk of misdiagnosis.…”

Assessing Trifecta Achievement after Percutaneous Cryoablation of Small Renal Masses: Results from a Multi-Institutional Collaboration

“…Additionally, the lack of a biopsy of the ablated area is a limitation of our study, considering that it could have ruled out false positive recurrences. The enhancement persistence in the ablated area can last for over a month after the procedure [30], and the lack of evidence on this topic make the management of these patients challenging.…”

The Use of Ultrasound Contrast in Interventional Radiology

“…18 19 CEUS has been applied in a range of ablative modalities, including microwave ablation, alcohol ablation, radiofrequency ablation, cryoablation, and irreversible electroporation. 20 21 Solbiati et al demonstrated much lower partial ablation rates using CEUS than conventional means (16.1% vs. 5.9%). 22…”