Application of real-time virtual sonography in guidance of radiofrequency ablation of hepatic tumors

Aims: To employ real-time virtual sonography (RVS) during US-guided radiofrequency ablation (RFA) for treatment of hepatic tumors.

Methods: An EUB-6500 ultrasound machine (Hitachi Medical Corporation, Japan) equipped with RVS was used in this study. The study group comprised 39 patients with totally 50 hepatic tumors. The pathologies included 31 hepatocellular carcinomas, 18 liver metastases, and one cholangiocarcinoma. The size of the tumor ranged from 0.9 to 9.3cm (mean: 3.0cm). Thirty-one lesions were not more than 3.0cm in size. The remaining 19 lesions were larger than 3.0cm. The source images used for RVS were CT scan in 44 lesions and MRI in 6 lesions. All lesions were treated with RFA guided by real-time 2D US in combination with RVS. The patients received CT scan or MRI one month after the procedure to evaluate the treatment efficacy of RFA.

Results: Irrespective of tumor size, thirty-nine lesions (39/50, 78%) showed no evidence of viable tumor in subsequent imaging study after RFA, while 11 lesions (11/50, 22%) showed viable tumor after RFA. In 31 lesions not more than 3.0cm in size, 25 lesions showed no viable tumor after RFA (25/31, 80.6%), while 6 lesions showed viable tumor (6/31, 19.4%). In the remaining 19 lesions larger than 3.0cm, 14 lesions showed no viable tumor after RFA (14/19, 73.7%), while 5 lesions showed viable tumor (5/19, 26.3%).

Conclusions: Our experience showed that it is feasible to apply RVS during US-guided RFA for hepatic tumors.