Ten-year experience of percutaneous image-guided radiofrequency ablation of malignant renal tumours in high-risk patients.

OBJECTIVES: To evaluate survival and outcomes after percutaneous radiofrequency ablation (RFA) of malignant renal tumours in high-risk patients with long-term follow-up. METHODS: Between 2002 and 2009, 62 patients (71 tumours), with a median age of 73.5 years (20-87), consecutively treated with RFA under ultrasound or computed tomography guidance for malignant renal tumours were retrospectively selected and prospectively followed until 2012, including 25 patients (40.3 %) with solitary kidney and 7 cystic cancers. Maximal tumour diameters were between 8 and 46 mm (median: 23 mm). RESULTS: Radiofrequency ablation was technically possible for all patients. Mean follow-up was 38.8 months (range: 18-78 months). Primary and secondary technique effectiveness was 95.2 % and 98.4 % per patient respectively. The rates of local tumour progression and metastatic evolution were 3.2 % and 9.7 % per patient and were associated with tumour size >4 cm (P = 0.005). The disease-free survival rates were 88.3 % and 61.9 % at 3 and 5 years. No significant difference in glomerular filtration rates before and after the procedure was observed (P = 0.107). The major complications rate was 5.9 % per session with an increased risk in the case of central locations (P = 0.006). CONCLUSIONS: Percutaneous renal RFA appears to be safe and effective with useful nephron-sparing results. KEY POINTS: • Radiofrequency ablation (RFA) is a well-tolerated technique according to mid-term results. • RFA for malignant renal tumours preserved renal function in high-risk patients. • Mid-term efficacy of RFA was close to that of formal conservative surgery. • Tumour size and central location limit the efficacy and safety of RFA.

Radiologically-guided thermal ablation of renal tumours.

Thermal ablation techniques for renal tumours have become the norm in surgically at-risk patients. These percutaneous treatments are locally effective, particularly for tumours measuring less than 4cm. Larger tumours may be treated by adapting the technique and strategy. Multidisciplinary discussion is essential before any decision, in order to decide on the most appropriate technique. Radiofrequency is simple, effective and inexpensive. Cryotherapy is more complex and should be preferred when the tumour is large or there is vascular or urinary tract contact. Microwaves can be used to treat larger tumours. Morbidity is low, but good knowledge of these techniques and of dissection is required to avoid injury to neighbouring digestive or urinary structures.