111 - Renal Biopsy Before vs During Ablation: A Retrospective Comparison of Biopsy Yield, Ablation Success, Complications, and the Frequency of Treating Benign Disease

Monday, April 13, 2026

3:18 PM - 3:27 PM ET

Presenting Author(s)

RL

Rahman Ladak, BS

Medical Student
Schulich School of Medicine & Dentistry, Western University, Canada

Author/Co-author(s)

Fu (Jorden) Lo, MD, BSc

PGY2 in Diagnostic Radiology
London Health Sciences Centre, Canada
AM

Amol Mujoomdar, MD FSIR

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

Roman Kozak, MD

Associate Professor
Department of Medical Imaging, Western University, Canada
LC

Leandro Cardarelli Leite, MD

Interventional Radiologist
University of Western Ontario, Canada
DC

Derek W. Cool, MD, PhD

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

Purpose: To determine whether performing a renal biopsy during renal ablation procedures affects the biopsy diagnostic yield or the ablation procedural outcomes when treating known or suspected renal cell carcinoma (RCC).

Materials and Methods: A retrospective study reviewed all renal biopsy and ablation procedures from May 2007 to May 2021 at a single institution. All small, solitary T1a renal masses (≤4cm) that were sent for biopsy and/or ablation were included. Patients with metastatic disease were excluded. A total of 378 patients (mean age 67.6 years, male:female 240:138, mean tumour size 2.6±0.8 cm) were included. 110 patients had biopsy during ablation (Ax+Bx, RFA:Cryo:MWA 90:14:6, mean tumour size 2.6±0.7 cm, mean RENAL Nephrometry score 6.2±1.6), 148 had biopsy before ablation (Ax-, RFA:Cryo:MWA 81:55:12, mean tumour size 2.7±0.7 cm, mean RENAL Nephrometry score 6.1±1.5), and 120 had biopsy without following ablation treatment (Bx-, mean tumour size 2.5±0.9 cm, mean RENAL Nephrometry score 6.1±1.7). Statistics were calculated using Fisher’s exact test.

Results: The diagnostic yield for biopsy during ablation (Ax+Bx) was 85% (n=93/110), which was significantly lower (p=0.04) than the 92% (n=246/268) diagnostic rate for biopsy before (Ax-) and without (Bx-) ablation. The timing of biopsy did not significantly affect (p=0.85) the success rate of ablation, as achieving complete RCC ablation in a single procedure (primary technical success) was 88% (n=97/110) for Ax+Bx and 87% (n=129/148) for Ax-. The adverse event rate was also not significantly affected (p=0.85) by biopsy timing and was 12% (n=13/110) for Ax+Bx in comparison to 13% (n=19/148) for Ax-. The Bx- adverse event rate was 2.5% (n=3/120). The frequency of treating benign disease was 13% (n=12/93) for Ax+Bx, which was significantly higher (p=0.0003) than 1.4% (n=2/148) for Ax-.

Conclusion: Combining renal biopsy and ablation did not significantly affect the rate of ablation technical success or the post-ablation adverse events, however, it did lower the biopsy diagnostic yield and increased the frequency of treating benign disease. This data provides valuable information when deciding whether to combine procedures or perform them sequentially.