Cryotherapy of Small Kidney Tumours under Local Anaesthesia

Background and objectives: Renal carcinoma is the third urological cancer with 11,000 new cases per year in France. During the 20 past years, the incidence of small and localized tumours increased, due to the development of medical imaging. These tumours, below 4 cm, are poorly aggressive and their growth is about 3 to 4 mm per year. The recent development of ablative techniques (radiofrequency, cryotherapy) offers an option for frail patients and those presenting absolute indications of nephron preservation. Percutaneous cryotherapy was developed with the help of 17 Gauge cryoprobes. The objectives of this study were to assess the feasibility, tolerance and results of percutaneous cryotherapy for small renal tumours under local anaesthesia and CT scan control. Patients and method: Patients with localized renal tumours < 4 cm and being unfit for anaesthesia or needing nephron preservation were prospectively included in the study. The initial evaluation included kidney MRI and tumour biopsy. Cryotherapy was performed under local anaesthesia and CT scan control. The evaluation was performed by the means of MRI at 24 hours, three months and every six months. The feasibility was defined as (i) the percutaneous access to the tumour, (ii) tolerance under exclusive local anaesthesia (visual analogue scale), (iii) absence of complications and (iv) the full treatment of the volume of the tumour (on the clinical and MRI control h24). The treatment failure was defined as the occurrence of tumour contrast and/or increasing of tumour volume during follow-up. No systematic biopsies were performed during the follow-up.Results: Between June 2009 and September 2013, 143 percutaneous treatments were performed in 129 patients (mean age 69.7 + / - 10 years) and 132 renal tumours < 4 cm. The feasibility of percutaneous cryotherapy was 98%. An exclusive local anaesthesia was done and we observed an excellent patient’s tolerance (average intraoperative and postoperative EVA respectively 1.59 and 0.70/10). The rate of complications was 9.1%, including two level 3 (1.4%). The hospital stay was 24h for 93% of the patients. Fourteen patients (10,8%) required a second cryotherapy for failure (6 patients), recurrence (5 patients) or new tumour (3 patients). With a mean follow up of 27 months, recurrence rate was 7.8%. Two years disease-free survival, specific survival and overall survival were respectively 92%, 100% and 97%.Conclusion: Percutaneous cryotherapy under local anaesthesia is a feasible and well-tolerated technique. It provides good oncological outcomes. Long term follow-up is required to assess the oncologic efficacy. The optimization of the procedure is needed in view to do it in an outpatient setting.