Usefulness of contrast-enhanced intraoperative ultrasound using Sonazoid in patients with hepatocellular carcinoma

Contrast-enhanced intraoperative ultrasound for hepatocellular carcinoma: high sensitivity of diagnosis and therapeutic impact

BACKGROUND

Postoperative early recurrence is a crucial issue in the treatment of hepatocellular carcinoma (HCC) patients. Some early recurrences seem to occur from minute tumors which were overlooked during both preoperative and intraoperative investigations. Therefore, it is urgently necessary to increase detectability of minute HCCs during operation. If they could be detected and resected during surgery, the prognosis should be improved. The purpose of this study is to investigate the usefulness of contrast-enhanced intraoperative ultrasound (CEIOUS) for the diagnosis and treatment of HCC.

METHODS

Institutional ethics committee approval and informed consent were obtained. Fifty-two patients (mean age 65 years; 38 males and 14 females) who underwent liver resection with either preoperative computed tomography during angiography (CTA) or CEIOUS with Sonazoid (perflubutane microbubble contrast agent) were studied. We determined the presence of HCC on the basis of the histopathological findings of resected specimens.

RESULTS

The sensitivity of CEIOUS [97.6% (95% CI 91.8-99.4)] was higher than that of CTA [89.4% (95% CI 81.1-94.3)]. The positive predictive values of CEIOUS [91.2% (95% CI 83.6-95.5) and CTA [91.6% (95% CI 83.6-95.9)] were similar. Eight new HCCs from 7 patients, which accounted for 9.4% (8/85) of the total HCCs, were correctly detected and diagnosed by CEIOUS, and we performed an additional partial hepatectomy in 3 of these 7 patients.

CONCLUSIONS

CEIOUS with Sonazoid provided increased sensitivity of detection of small HCCs compared with preoperative CTA, thereby leading to a more appropriate surgical procedure and contributing to complete tumor removal.

Intraoperative ultrasound in patients with hepatocellular carcinoma: from daily practice to future trends

Starting from the end of the 1970s, intraoperative ultrasound was introduced and developed to stage liver disease and guide the surgical interventions in patients with hepatocellular carcinoma. Without intraoperative ultrasound, it would probably be impossible to correctly define the hepatic segments as well as the limits of a tumor, also because of the existing wide variations in the anatomy. More importantly, intraoperative ultrasound allows for three-dimensional reconstruction of the relationships between the tumor, hepatic veins, and Glissonian pedicles. Such reconstruction is essential for planning the surgical strategy, which should be individualized in each patient with the aim to spare functional liver parenchyma. This work focuses on the role of intraoperative ultrasound to stage liver disease and to plan surgical resection, describing the most recent technical achievements.

New paradigm for management of hepatocellular carcinoma by imaging

Based on recent clinical practice guidelines, imaging is largely replacing pathology as the preferred diagnostic method for determination of hepatocellular carcinoma (HCC). A variety of imaging modalities, including ultrasound (US), computed tomography (CT), magnetic resonance imaging (MRI), nuclear medicine, and angiography, are currently used to examine patients with chronic liver disease and suspected HCC. Advancements in imaging techniques such as perfusion imaging, diffusion imaging, and elastography along with the development of new contrast media will further improve the ability to detect and characterize HCC. Early diagnosis of HCC is essential for prompt treatment, which may in turn improve prognosis. Considering the process of hepatocarcinogenesis, it is important to evaluate sequential changes via imaging which would help to differentiate HCC from premalignant or benign lesions. Recent innovations including multiphasic examinations, high-resolution imaging, and the increased functional capabilities available with contrast-enhanced US, multidetector row CT, and MRI have raised the standards for HCC diagnosis. Although hemodynamic features of nodules in the cirrhotic liver remain the main diagnostic criterion, newly developed cellspecific contrast agents have shown great possibilities for improved HCC diagnosis and may overcome the diagnostic dilemma associated with small or borderline hepatocellular lesions. In the 20th century paradigm of medical imaging, radiological diagnosis was based on morphological characteristics, but in the 21st century, a paradigm shift to include biomedical, physiological, functional, and genetic imaging is needed. A multidisciplinary team approach is necessary to foster an integrated approach to HCC imaging. By developing and combining new imaging modalities, all phases of HCC patient care, including screening, diagnosis, treatment, and therapy, can be dramatically improved.