What's new in urology.

Abstract

Energy-based ablation techniques There are a plethora of new techniques available to eradicate renal cell carcinoma (RCC) that have recently been evaluated. 1 The promise of these techniques is the ability to apply them through percutaneous or laparoscopic approaches with maximum renal parenchymal preservation. The most studied of these methods to date is percutaneous or laparoscopic cryotherapy, which attempts to obtain a core tumor temperature of 40°C with a double freeze/thaw sequence, monitoring by ultrasonography the ice-ball in an attempt to get a freeze margin 1 cm from the tumor. Several series of less than 50 patients have been reported, with subsequent imaging results showing eradication of tumor and resultant fibrosis. In these studies several patients have been followed with subsequent biopsy and only one residual tumor has been documented. Other methods include thermal ablation by radiofrequency, 2 microwave, laser interstitial treatment, and high intensity focused ultrasound. For most of these modalities human studies are as yet quite limited. High intensity focused ultrasound has the potential to be the least invasive, but skin burns and focusing through bone are unresolved problems. Interstitial photons and radioimmunotherapy studies are also beginning but no definitive information is available. Cryotherapy has the most promise at the moment, but each of these modalities will have to be evaluated with regard to longterm local recurrence and metastatic rates in direct comparison with standard extirpative techniques.