A total of 43 patients (6.1% of total ablative database) met inclusion criteria. The median age was 57 years (IQR 52-62) and pre-ablation GFR was 75.6 (IQR 69-86.3). The cryoablation technique involves anesthetizing the patient and using real-time ultrasound or computed tomography (CT) guidance for probe placement. Approximately 1 probe for each 1 cm of tumor is used and 1-2 cm spacing between probes is utilized. One or two 18-gauge core biopsies are performed and a freeze-thaw-freeze cycle of 10 minutes-5 minutes-10 minutes is performed. CT imaging is done every 2-4 minutes during freeze cycles to monitor the ice ball and immediate post-ablation imaging is routinely performed to evaluate for complications and ensure technical success. Follow-up imaging is obtained at 3- and 6-months post-ablation and every 6-12 months after depending on clinical and patient factors.
Median radiological follow-up was 22 months (IQR 9-42). One patient (2.3%) developed local recurrence and two (4.6%) developed metastatic disease. Both patients who developed metastatic disease had a prior nephrectomy for high-risk pathology. The patient who developed a recurrence underwent repeat ablation and is currently without recurrence. No patients died from RCC during the study timeframe.
Dr. Zaid concluded that cryoablation has good short term oncologic outcomes and an excellent safety profile. Further, there is a potential role for repeat ablation following local recurrence. Cryoablation in healthier patients – particularly those with challenging surgical anatomy or prior kidney surgery – warrants continued prospective analysis.
First author: Harras Zaid, MD, Mayo Clinic
Written By: Shreyas Joshi, MD, Fox Chase Cancer Center
at the 2017 Genitourinary Cancers Symposium - February 16 - 18, 2017 – Orlando, Florida USA