Multi-institutional registry on a cohort of 310 patients with biopsy-proven renal cell carcinoma treated by Radiofrequency ablation. All patients will be included consecutively and retrospectively in all centers to obtain the required number of patient followed during 5 years.

Radiofrequency ablation (RFA) of renal cell carcinoma (RCC) is actually used in elderly patients with small renal tumors (diameter ≤ 4 cm) and presenting a high risk of surgery (due to co-morbidity) and/or reduced renal function. RFA is a minimally invasive technique, considered as an alternative to surgery to limit morbidity and to preserve kidney function. The technique is well known and has proven his efficacy for the treatment of small tumors.

An enlargement of the indications of RFA to patient without contra-indication to surgery will depend on the efficacy of the technique.

The main objective of the study is to evaluate the local efficacy of the ablation based on the technical success, and on the evaluation of local cancer recurrence over 5 years.

Inclusion Criteria:

• Patient treated with percutaneous RFA
• Patient with diagnosis of renal masses with a maximum of 3 masses treated during the ablation
• The diameter of the tumor must be ≤ 40 mm, characterized by CT-scan or MRI
• The histology of the tumor must be biopsy-proven or the patient must have previous surgical ablation of renal tumor (ipsi or contralateral)

Exclusion Criteria:

• Patient treated by surgery or laparoscopy
• Benign tumors
• No histological diagnosis (no biopsy or no previous treated renal carcinoma)
• Patient having secondary malignant sites, ganglions or visceral metastatic cells or endo-venous extend at the time of RFA
• Patient having a diagnosis of primary or secondary extra-renal tumor location and not into remission
• Patients treated with antiangiogenic drugs during the 6 months prior RFA.

The population concerned by the study consists in patients treated by percutaneous image-guided radiofrequency for renal tumor. The treated tumors have a diameter ≤ 4 cm characterized by computed tomography (CT) or Magnetic resonance imaging (MRI).