Page 179 - ebook HCC

176 PROGRAMME AND ABSTRACTS GENEVA, SWITZERLAND EASL HCC SUMMIT 177
FEBRUARY 13 - 16, 2014

OTHER DIAGNOSTIC TOOLS: CEUS,
PET-CT AND OTHERS

Fabio Piscaglia 1
1 Div of Internal Medicine, Dpt Medical and Surgical Sciences,
University of Bologna, Bologna, Italy

Corresponding author’s e-mail: fabio.piscaglia@unibo.it

Contrast Enhanced Ultrasound (CEUS) is performed in Europe with the single contrast Moreover, some subtle CEUS features, such as rapid and marked wash-out tend to
agent registered for liver investigation, namely sulfur exafluoride (SonoVue®) , which is a suggest the possibility of CCC based on expert opinion, but endorsed by the European
pure blood pool agent, whereas Sonazoid® is also registered for liver investigations in Far Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB). Briefly,
East Asian Countries. The latter agent undergoes uptake by the reticulo endothelial cells it has to be acknowledged that the “typical” CEUS pattern of HCC may include a ≤1%
after having circulated in the arterial and venous phases. The vascular phases (arterial, risk of CCC and that the role of such risk of misdiagnosis has been differently weighted
portal and venous) are the same for the various contrast agents. by various hepatology societies. On practical grounds, CEUS is usually less sensitive
CEUS is able to depict the typical vascular pattern of enhancement of hepatocellular than CT or MRI in detecting wash-out, whereas it is highly sensitive in identifying arterial
carcinoma (HCC), corresponding to homogeneous hyperenhancement in ther arterial hyperenhancement thanks to its real time modality. Hence, in the instance in which CEUS
phase followed up by wash-out in the venous phase. However this pattern is observed shows a typical malignant pattern, but discrepant from CT or MRI (which are always
also in approximately 50% of the cases of mass forming peripheral CholangioCellular recommended to stage the disease), with wash-out detected only by CEUS but not by CT/
Carcinoma (CCC) arising in cirrhosis. At variance, the latter entity (CCC) usually (but not MRI, a high suspicion of CCC should arise.
always) doesn’t show wash-out at contrast enhanced CT or MRI, due to the different When instead wash-out is not detected by CEUS, but it is present at CT/MRI a diagnosis
CLINICAL SPEAKERS ABSTRACTS introduced in the American (AASLD) guidelines in 2005, was dropped from both the 2011 Positron Emission Tomography (PET) may be performed with different tracers. The most CLINICAL SPEAKERS ABSTRACTS
of HCC is reached, with the lack of wash out at CEUS suggesting a more differentiated
pharmacokinetics of CT/MRI and ultrasound contrast agents. For these reasons and
tumor than in cases where wash-out is present at all imaging modality.
specifically the risk of false positive diagnosis of HCC in case of CCC, CEUS, initially
interesting for HCC are 11C-acetate and 18F-fluoro-deoxyglucose (18F-FDG, classical
AASLD and the 2012 EASL guidelines for the diagnosis of HCC. However, the same
tracer). High signal with 11C-acetate are usually found in well differentiated HCC, whereas
choice was not made by other continental and national important hepatology societies
the contrary happens with 18-FDG, the latter also in sites of metastatic disease. However,
(Asian, Japanese, Italian). The pattern of hyperenhancement+wash out at CEUS may
both tracers are not highly sensitive and they are no better than CT or MRI in terms of
not be 100% specific for HCC, but it is anyhow totally specific for malignancy. Conversely
CCC may show hyperenhancement in the arterial phase at CT/MRI, but tend to lack
FDG is also poorly sensitive for lung metastasis from HCC smaller than 1 cm. Thus,
venous wash-out, as it happens in some non malignant (expecially in some high grade
PET has no current role in the diagnostic algorythm of HCC. It has rather a prognostic
dysplastic) hepatocellular nodules. This means that no definitive diagnosis is possible accuracy, despite 18-FDG is more sensitive than nuclear scan for bone metastasis. 18-
by CT/MRI imaging alone by the latter techniques (not even of benign versus malignant role, since high tumor signal with 18-FGD is associated with higher recurrence rate and
nature) in case of CCC. The lack of a diagnostic pattern for CCC at CR/MRI would imply shorter time to progression after radical treatments of HCC. PET with 18FDG may also be
a biopsy, whose false negative rate at first attempt is reported as high as 35% in small utilized to detect extrahepatic spread when this diagnosis is relevant and the risk for it is
nodules (Forner, Hepatology 2008). Moreover, the rate of CCC among newly developed consistent (primary HCC >5 cm) (Lee JE, WJG 2012).
liver nodules has been repeatedly reported to range between 0.5 and 2%. Thus, since
only half CCC show the typical HCC pattern, the risk of misdiagnosis would be less than
1% of newly developed nodules and in most instance, a misdiagnosis would not affect the
treatment strategy (e.g. surgical resection).