Although surgical resection reŽmains the standard of care for renal cell carcinoma, there are a number of reasons percutaneous image-guided ablative therapies are beŽcoming established as an alternative for selected patients [1-3]. Ablation therapies are associated with less treatment-related morbidity and mortality than resection and can therefore be used in patients who are not surgical candidates because of comorbid conditions or because of the need to preserve renal funcŽtion, especially in those with a soliŽtary kidney or minimally functionŽing contralateral kidneys. Another consideration is the upsurge in the diagnosis, particularly in the elŽderly, of small renal cell carcinoŽmas, which are found largely because of the increased use of toŽmographic imaging [4]. FurtherŽmore, if there is residual or recurŽrent disease after any treatment, ablative therapies can be performed or repeated over time. Three percutaneous image-guided ablative therapies are now in general Use: radiofrequency ablation [5], cryoablation [1,6], and microwave ablation [3]. In each case, one or more needles are inserted into a tumor, and energy (heat or freezing) is used to destroy the tumor. The different techniques vary in terms of the time needed for treatment, ability to monitor the process, and other patient-dependent and tumor-dependent factors. Interventional radiologists in collaboration with urologists select the most appropriate treatment for each patient.