Safety Considerations and Local Tumor Control Following Percutaneous Image-Guided Cryoablation of T1b Renal Tumors

Objective To retrospectively assess the safety and oncological efficacy of percutaneous image-guided cryoablation (CA) of T1b ([>4 cm/<7 cm) renal tumors. Materials and Methods Institutional electronic records were retrospectively reviewed to identify the patients who had undergone percutaneous CA of T1b renal tumors between 2008 and 2016. CA was proposed by a multidisciplinary tumor board for cases with poor renal function or a single kidney; unsuitable for surgical resection; or genetic syndromes predisposing to multiple hereditary renal tumors. Patients' demographics, procedural and follow-up data were accurately collected and analyzed. Results Twenty-seven consecutive patients (12 females, 15 males; mean age 72.3 +/- 14.3 years) were included. Mean tumor diameter was 47.9 +/- 6.3 mm. MRI guidance was used in 6/27 cases (22.2%) and CT guidance in the remaining 21/27 (77.8%) cases. Hydro-and/or carbo-dissections were necessary in 21/27 cases (77.8%). Complications graded >= II were reported in three (11.1%) patients. Technical success and technical efficacy were 100 and 87.5%, respectively. Local tumor control (LTC) evaluated at imaging follow-up >= 6 months was 82.6, 72.3 and 60.3% at 12-, 24- and 36-month follow-up, respectively. One patient passed away 3 months after CA due to the metastatic evolution of the primary kidney cancer. Conclusion Percutaneous CA of T1b renal tumors is safe and satisfactory rates of LTC are expected at the early follow-ups. Further studies are needed to confirm the long-term efficacy of this procedure.