Radiofrequency Ablation Assisted by Real-Time Virtual Sonography and CT for Hepatocellular Carcinoma Undetectable by Conventional Sonography

Abstract

Real-time virtual sonography (RVS) is a diagnostic imaging support system, which provides the same cross-sectional multiplanar reconstruction images as ultrasound images on the same monitor screen in real time. The purpose of this study was to evaluate radiofrequency ablation (RFA) assisted by RVS and CT for hepatocellular carcinoma (HCC) undetectable with conventional sonography. Subjects were 20 patients with 20 HCC nodules not detected by conventional sonography but detectable by CT or MRI. All patients had hepatitis C-induced liver cirrhosis; there were 13 males and 7 females aged 55-81 years (mean, 69.3 years). RFA was performed in the CT room, and the tumor was punctured with the assistance of RVS. CT was performed immediately after puncture, and ablation was performed after confirming that the needle had been inserted into the tumor precisely. The mean number of punctures and success rates of the first puncture were evaluated. Treatment effects were evaluated with dynamic CT every 3 months after RFA. RFA was technically feasible and local tumor control was achieved in all patients. The mean number of punctures was 1.1, and the success rate of the first puncture was 90.0%. This method enabled safe ablation without complications. The mean follow-up period was 13.5 month (range, 9-18 months). No local recurrence was observed at the follow-up points. In conclusion, RFA assisted by RVS and CT is a safe and efficacious method of treatment for HCC undetectable by conventional sonography.

Utility of percutaneous radiofrequency ablation alone or combined with transarterial chemoembolization for early hepatocellular carcinoma

“…However, RFA monotherapy may increase the risk of relapse in cases where the HCC is comparatively large, when it exists near the surface of the liver or near vessels that are hard to treat due to the risk of coagulation necrosis (8). A variety of methods, including imaging support such as Real-Time Virtual Sonography (9), have been devised in the past to counteract these difficulties.…”

Fusion imaging for intra-operative ultrasound-based navigation in neurosurgery

“…Fusion imaging was first introduced by radiologists for the treatment of hepatic neoplasms or lesions [13][14][15][16][17]. To target hepatic lesions, especially when characterized by poor sonographic signal [18], they perform an US-guided, minimal invasive (e.g., RF ablation) procedure merging the iUS imaging with CT or other modalities.…”

New modalities of treatment for hepatocellular carcinoma

“…However, the short durations of the different vascular phases, absence of real-time imaging guidance and increased radiation exposure are the disadvantages of using these imaging techniques. 78,79 To overcome these problems a method called "fusion imaging' or "real time virtual sonography", that synchronizes real-time US and CT or MRI, is introduced. 80 Two cohort studies showed an excellent technical success rate, safety and effectiveness for RFA using fusion imaging.…”