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.