35 - Does the Degree of Renal Sinus Extension Impact Success and Adverse Events for Cryoablation of T1 Renal Cell Carcinoma?

Sunday, April 12, 2026

3:36 PM - 3:45 PM ET

Presenting Author(s)

AA

Abdulaziz AlQubaisi, MBBS

Fellow
Dept of Medical Imaging, Western University, London, ON, Canada, Canada

Author/Co-author(s)

GW

Ginger Watts, MD

Assistant Professor
Dept of Medical Imaging, Western University, London, ON, Canada, Canada
AM

Amol Mujoomdar, MD FSIR

Professor of Interventional Radiology, Oncology and Medical Biophysics
Western University, Canada
LC

Leandro Cardarelli Leite, MD

Interventional Radiologist
University of Western Ontario, Canada
SP

Stephen Pautler, MD

Professor
Division of Urology, Dept of Surgery, Western University, London, Ontario, Canada, Canada
DC

Derek W. Cool, MD, PhD

Radiologist - Assistant Professor
Department of Medical Imaging, Western University, London ON, Canada, Canada

Purpose: Renal tumors are classified based on location relative to the renal cortex as exophytic or endophytic, however, this classification does not distinguish tumors with regards to the degree of renal sinus extension. We aim to assess procedural success and adverse events after cryoablation of solitary renal cell carcinoma (RCC) for those with and without extension into the renal sinus.

Materials and Methods: A retrospective study of all patients with solitary RCC treated with cryoablation from January 2004 to June 2022 with at least 1 imaging follow up. Patients with multiple renal masses were excluded. The patients were divided into two groups based on tumor location relative to the renal sinus of >1 mm or less than 1 mm distance between the tumor edge and the renal sinus. For the latter group, renal sinus extension was subcategorized into >25% or <25% of the tumor diameter within the renal sinus measured based upon maximum tumor diameter perpendicular to the renal sinus. adverse events and primary/secondary technical success were assessed. Primary technical success was defined as complete ablation from first intervention and secondary technical success as complete ablation after more than one ablation. The tumors were also classified as endophytic and exophytic based on the RENAL nephrometry score and similar outcomes were assessed.

Results: 144 patients had a solitary RCC treated with cryoablation. 64 patients had tumors at or extending into the renal sinus (mean age was 65.3 ± 9.8 years, M:F 39:25, mean tumor size was 3.8 ± 0.1 cm) while 80 tumors were at least 1mm away (mean age was 63.7 ± 10.5 years, M:F 61:19, mean tumor size was 3.4 ± 1.2 cm). Adverse events were slightly higher in the renal sinus extension group (20% vs. 13%), but not statistically significant (p = 0.254). Both groups had similar primary (77% vs 79.0%) and secondary (90% vs 93.0%) technical success, respectively. For patients who had >25% renal sinus extension, primary technical success was lower than those with renal sinus extension <25% (67% vs 85%, p = 0.079) and secondary technical success (87% vs 91%) and adverse events (20%) were similar. Endophytic (18) and exophytic (126) renal tumors had similar primary (78% for both) and secondary (94% vs 91%) technical success and adverse event rates (17% vs 16%) respectively.

Conclusion: This study demonstrates that tumors with greater than 25% extension into the renal sinus may have lower primary technical success, but with similar secondary technical success and adverse events. This may be a better predictor of ablation success than the existing endophytic/exophytic classification.