 US or CT imaging is used during and immediately after RF to ensure accuracy of the thermal lesion created and to exclude complications. After completion of the procedure, the patient is transported to the Medical Surgical Day Unit for observation, recovery, and further pain control as required. Immediate post-treatment CBC and serum creatinine levels will be measured. Urinalysis will be performed. The patient is discharged home accompanied by a relative or a friend approximately 4 hours after completion of the RF procedure. 