 For patients that have an ultrasound guided procedure, the RFA procedure will be done in the routine operating room in an open fashion, the kidney will be exposed surgically in the usual way in anticipation of the partial or radical nephrectomy. The kidney tumour will be located by gross inspection, palpation and with the aid of intraoperative US if required. In this case, the RFA probe will be inserted directly into the lesion. For those patients that have a CT guided procedure along with US, the procedure will be done in the MPOR and the RFA probe will be inserted percutaneously into the lesion, prior to opening and exposing the kidney. If the surgery is unable to be performed in the MPOR, the patient will transferred to a routine operating room, while under general anesthetic, to have their surgery. They will be accompanied by the anesthesiologist. 