Summary
This study explores the use of high-intensity focused ultrasound (HIFU) for the noninvasive ablation of renal tumors. While clinical applications of HIFU for renal tumors have primarily been experimental, the study provides specific details about a patient with renal cell carcinoma who underwent HIFU with curative intent and long-term follow-up.
The HIFU technology used generated ultrasound waves through a cylindrical piezoelectric element focused by a paraboloid reflector. HIFU was applied to three tumors in three sessions, with the patient under general anesthesia or sedation analgesia. Follow-up magnetic resonance imaging (MRI) was conducted over six months.
The results showed that after treatment, MRI revealed necrosis in two of the tumors located in the lower kidney pole within 17 and 48 days, respectively. The necrotic tumor areas gradually decreased in size within the subsequent six months. However, a tumor located in the upper pole was not affected by the treatment due to the absorption of ultrasound energy by interposed ribs. General anesthesia was required to apply high-energy levels of focused ultrasound. Successful HIFU application achieved thermal ablation of renal tumors without lesions occurring outside of the target area. The effectiveness of HIFU application depended on optimal energy coupling, sufficiently high ultrasound energy levels, and the use of general anesthesia.
In conclusion, this study demonstrates that contactless, noninvasive HIFU can be applied to achieve thermal ablation of renal tumors, with potential benefits for patients. However, successful HIFU treatment relies on precise energy coupling and suitable energy levels, and it often requires the use of general anesthesia.
