Tumor Cryoablation

Background and indications

Percutaneous cryoablation is a tumor destruction technique using cold, employing cryoprobes that deliver gas (argon) cooling tissue to -40°C. It is applicable to many locations: renal, pulmonary, hepatic, bone, and soft tissue tumors. Its main advantage is real-time visualization of the treatment zone (ice ball) on CT or MRI, allowing precise margin control.

Main indications include: small renal cell carcinoma (T1a ≤ 4 cm), lung tumors (primary or metastatic ≤ 3 cm), painful bone metastases, recurrent soft tissue tumors, and situations where heat-based thermal ablation (RFA/MWA) is contraindicated (proximity to heat-sensitive structures).

Pre-procedure assessment

Assessment includes recent tumor imaging (CT and/or MRI), complete staging workup, blood panel including renal function and coagulation, and multidisciplinary tumor board discussion. Technical feasibility (access, number of cryoprobes needed) is planned.

Procedure

Under general anesthesia and CT (or MRI) guidance, one to several cryoprobes (17G) are inserted into the tumor. Cryoprobe number depends on tumor size (1 probe for < 2 cm, 2-4 probes for 2-4 cm). Two freeze-thaw cycles are performed (freeze 10-15 min, thaw 5-8 min). The ice ball is monitored in real time on CT. The goal is to extend 5-10 mm beyond the tumor peripherally. The procedure takes 1 to 3 hours.

Results and scientific evidence

For T1a renal tumors, cryoablation offers 90-95% recurrence-free survival at 5 years with superior renal function preservation compared to partial nephrectomy. For lung tumors ≤ 2 cm, local control is 85-95% at 2 years. For bone metastases, pain improvement is achieved in 80-90% of cases.

Risks and complications

Complications vary by location: pneumothorax (20-30% for lung tumors, 5-10% requiring drainage), peritumoral hemorrhage (5-10%), local pain (20-40%), adjacent structure injury (< 2%, minimized by ice ball visualization). Peri-procedural mortality is below 0.5%.

Recovery

1-2 night hospitalization depending on location. Return to activities in 3-7 days. Control imaging at 1, 3, 6, and 12 months.

Practical information

The procedure is performed as a short inpatient stay or outpatient depending on the case. It is performed by an interventional oncology radiologist.