Kidney Clinical Reviews

J Urol 170(6 Pt 1): 2237-40.

PURPOSE: We present the preliminary results of patients with advanced stage renal malignancy treated with high intensity focused ultrasound (HIFU), and investigate the safety and feasibility of using HIFU in the treatment of selected patients with renal tumors. MATERIALS AND METHODS: HIFU treatment was performed in 12 patients with advanced stage renal cell carcinoma and 1 patient with colon cancer metastasized to kidney. Patients were followed after treatment to observe complications and long-term therapeutic efficacy. Complications and changes in symptoms seen at presentation were recorded. Mid stream urine specimens were sent for microscopy and serum creatinine was measured postoperatively. Followup radiological examinations were performed to detect tumor response to the ablation. RESULTS: A total of 13 patients received HIFU treatment safely, including 10 who had partial ablation and 3 who had complete tumor ablation. After HIFU hematuria disappeared in 7 of 8 patients and flank pain of presumed malignant origin disappeared in 9 of 10 patients. Postoperative images showed decrease in or absence of tumor blood supply in the treated region and significant shrinkage of the ablated tumor. Of the 13 patients 7 died (median survival 14.1 months, range 2 to 27) and 6 were still alive with median followup of 18.5 months (range 10 to 27). CONCLUSIONS: This preliminary experience suggests that HIFU could be safe and feasible in the treatment of patients with advanced renal malignancy

J Urol 167(6): 2397-403

PURPOSE: Noninvasive tumor ablation can be achieved by extracorporeally induced high intensity focused ultrasound. Clinical high intensity focused ultrasound performed to date for renal tumors have only been experimental in nature. We present specific details on a patient with renal cell carcinoma who underwent high intensity focused ultrasound with curative intent and long-term followup examinations. MATERIALS AND METHODS: Ultrasound waves were generated by a cylindrical piezoelectric element focused by a paraboloid reflector. High intensity focused ultrasound was applied to 3 tumors in 3 sessions with the patient under general anesthesia or sedation analgesia, followed by magnetic resonance imaging for 6 months. RESULTS: After treatment magnetic resonance imaging showed necrosis in the 2 tumors in the lower kidney pole within 17 and 48 days, respectively. The necrotic tumor area shrank thereafter within 6 months. The tumor in the upper pole was not affected by treatment due to absorption of the ultrasound energy by the interposed ribs. General anesthesia was required to apply high energy levels of focused ultrasound. Absorption of high intensity focused ultrasound in the tissue induced sharply demarcated thermonecrosis. For 50 years patients have been treated with high intensity focused ultrasound for different indications, focusing on the brain, eyes, prostate, liver and bladder. For the kidney experimental but only few clinical studies indicate sufficient tissue ablation. CONCLUSIONS: In our case contactless noninvasive application of high intensity focused ultrasound to 2 renal carcinomas achieved thermal ablation. When high intensity focused ultrasound energy was coupled correctly, no lesions occurred outside of the target area. Successful high intensity focused ultrasound application depended on optimum energy coupling, a sufficiently high ultrasound energy level and general anesthesia.