34 - Percutaneous Thermoablation for Renal Tumors Greater Than 4 Cm: A Single Center Experience

Sunday, April 12, 2026

3:27 PM - 3:36 PM ET

Presenting Author(s)

SH

Shaan Haider, BS

MS2
Medical College of Georgia at Augusta University, United States

Author/Co-author(s)

AA

Arun Arumugam, BA

MS2
Medical College of Georgia at Augusta University, United States
DZ

Dongyu Zhang, BS

MS2
Medical College of Georgia at Augusta University, United States
RK

Rohan Kapuria, BS

MS4
Medical College of Georgia at Augusta University, United States
HW

Hanping Wu, M.D.

Assistant Professor, Interventional Radiology
Medical College of Georgia, United States

Purpose: To investigate the technical success, safety outcomes, and tumor recurrence of renal tumors greater than 4 cm treated by percutaneous microwave ablation or cryoablation.

Materials and Methods: This study included patients with renal tumors larger than 4 cm who underwent thermoablation and were not candidates for surgery. From 2015 to 2024, retrospective database review identified 25 patients (16 males, median age 70) who underwent CT-guided microwave ablation (n=5), cryoablation (n=16), or embolization+cryoablation (n=4) of renal tumors. 25 procedures were performed for 25 tumors with a median size of 4.6 cm (range, 4.0 cm to 8.6 cm) and median RENAL score of 8 (range, 5 to 11). On pathologic examination, a majority of tumors (72%) were renal cell carcinoma.

Results: Hydrodissection and/or pneumodissection were performed in 10 cases, and pyeloperfusion was performed in 4 cases to protect the renal collecting system. Technical success, determined by immediate post-procedure imaging, was achieved in 24 patients (96%). All patients tolerated the procedure well, but there were 10 moderate and 4 severe adverse events. The hemoglobin drop in the 24-hour post-operative period ranged from –1 to 4.3 g/dL, with a median of 0.9 g/dL. 1 patient required blood transfusion due to severe perirenal hematoma; 1 patient required embolization to control the bleed. The rise in post-operative creatinine ranged from -0.26 to 1.79 mg/dL, with a median of 0.16 mg/dL. 1 patient required extended hospital admission (13 days) for management of AKI/hyperkalemia; 1 patient in the microwave ablation group developed an abscess requiring drainage tube placement; 2 patients required ureteral stent placement for hydronephrosis secondary to ureteral injury.

During a median follow-up period of 17 months (range, 1 to 46 months), viable tumors or recurrence were observed in 25% of cryoablation cases (4/16), 40% of microwave ablation cases (2/5), and none of the embolization+cryoablation cases (0/4). All 6 cases of recurrence were successfully treated by follow-up cryoablation. Needle-tract seeding implantation was observed in 2 cases. 1-year recurrence-free survival was 80.0% and 1-year overall survival was 100%.

Conclusion: Percutaneous thermoablation for renal tumors larger than 4 cm is an effective treatment option for preventing tumor recurrence and improving long-term survival in patients not suitable for surgery. Adverse events are likely to occur, so patients must be closely monitored post-operatively.