Assessment of treatment efficacy in radiofrequency ablation for renal tumors by contrast-enhanced ultrasonography / 中华泌尿外科杂志

ABSTRACT

Objective To discuss the utility of contrast-enhanced ultrasonography (CEUS) in the assessment of treatment efficacy of radiofrequency ablation (RFA) in patients with renal tumors.Methods Forty-seven patients (40 renal cell carcinomas and 7 angiomyolipomas of kidney) with 49 renal tumors were treated with RFA. Tumors were ablated by laparoscopy-assisted (n= 30) and open surgical (n= 17) RFA. The CEUS and contrast-enhanced CT were performed 1 week after treatment to assess the necrotic area. Technical success was defined as elimination of areas that enhanced at imaging within the entire tumor. Results Forty-seven (95. 9%) of 49 tumors were successfully ablated. The mean length of the major axis at the maximal necrotic area was 4. 6 cm. Compared with the lesions before RFA, the necrotic areas were bigger in 45 patients, identical in 3 patients, and smaller in 1 patient. Six lesions showed a residual enhancement at the portion adjacent to the normal renal parenchyma on follow-up CEUS, while 2 were confirmed by CT scans. The sensitivity and specificity of CEUS for detection of residual tumors were 100. 0% and 91.8%, respectively. All patients survived in the follow-up period ranging from 4 to 21 months. Conclusion CEUS combined with CT could be useful for evaluating treatment efficacy of RFA for renal tumors.