Radiofrequency Ablation of Renal Cell Carcinoma: A Systematic Review

Abstract

The widespread use of abdominal cross-sectional imaging such as computed tomography (CT) and magnetic resonance imaging (MRI) has resulted in a significant rise in the frequency of incidentally detected renal masses (Mouraviev et al., 2006). Most tumors are small and localized renal tumors have been shown to be of a very early clinical stage. It is estimated that in 2009, 57,760 new cases of kidney caner will be diagnosed and 12,980 patients will die of the disease in the United States (American Cancer Society, 2009). Nephron-sparing surgery such as partial nephrectomy remains the gold standard in patients with small renal cell carcinomas (RCCs), with oncologic outcomes similar to the use of a radical nephrectomy (Bandi et al., 2008). However, both open and laparoscopic partial nephrectomy are associated with a significant complication rate and laparoscopic partial nephrectomy is also associated with a significant learning curve, increased warm ischemia time, and a higher morbidity rate as compared with open partial nephrectomy (Gill et al., 2003). Many cases with incidentally detected small renal tumors are found in elderly patients with significant comorbidities, and these patients may not be good surgical candidates. Therefore, several investigators have utilized a variety of energy-based tissueablative technologies such as radiofrequency (RF) ablation, cryoablation, high-intensity focused ultrasound, microwave thermotherapy, and interstitial photon irradiation as alternative treatment options of small renal masses (McAchran et al., 2005). Among these minimally invasive ablative techniques, RF ablation and cryoablation are the most commonly utilized methods and have been extensively studied. For short-term results, cryoablation (4.6% tumor-persistent disease and complication rate of 10.6%) is considered better than RF ablation (7.9% and 13.9%, respectively) (Weld & Landman, 2005). However, there are no prospective comparative studies to suggest that cryoablation is more effective than RF ablation for the treatment of small RCCs. RF ablation has several advantages with a superior relationship between the RF-probe diameter and the volume of ablated tissue (Mahnken et al., 2005). RF ablation also provides many potential benefits, including a low complication rate, reduced morbidity, shorter hospital stay, absence of an ischemic period, possible conscious sedation, less expensive than surgery, and the ability to avoid the higher risk of surgical resection in elderly patients (Lotan & Cadeddu, 2005; Mouraviev et al., 2006; Park et al., 2007). Furthermore, RF ablation may minimize destruction of normal renal tissue and thus minimizes removal of functional nephrons (Mylona et al., 2009). For the intermediate term, the oncologic outcomes of RF ablation appear comparable to that of