Transient Elastography (FibroScan®) for Liver Fibrosis Staging

PICHON RIVIERE, A.; AUGUSTOVSKI, F.; GARCIA MARTI, S.; GLUJOVSKY, D.; ALCARAZ, A.; LOPEZ, A.; BARDACH, A.; CIAPPONI, A; VALANZASCA, P

Documento de Evaluación de tecnologías Sanitarias

IECS

Año: 2013 p. 1 - 30

1668-2793

Liver fibrosis is a health condition associated to significant morbidity and mortality. It represents the final pathway to several liver diseases, whose last stage is cirrhosis. The main diseases leading to liver fibrosis include hepatitis C and excessive alcohol consumption. In Argentina, hepatitis C affects 2% of the population and 85% of them progresses to chronic hepatitis. Liver fibrosis staging is useful to obtain an adequate estimate of prognosis, survival and treatment in this patient group. The gold standard for the assessment of fibrosis in chronic liver conditions is currently a liver biopsy. The biopsy is an expensive invasive method, with inter and intra-observer variability and risk of severe complications and death. Therefore, several non-invasive techniques have been developed as potential alternative methods to biopsy such as FibroScan® for live fibrosis staging.TechnologyTransient elastography (FibroScan®) is a non-invasive diagnostic method that uses ultrasound in combination with low frequency vibration to assess the extent of liver fibrosis.PurposeTo assess the available evidence on the efficacy, safety and issues related coverage policies for the use of transient elastography (FibroscanÒ) as staging method for liver fibrosis.MethodsA bibliographic search was carried out on the main databases: DARE, NHS EED, on Internet general search engines, in health technology evaluation agencies and health sponsors. Priority was given to the inclusion of systematic reviews; controlled, randomized clinical trials (RCTs); health technology assessments and economic evaluations; clinical practice guidelines and coverage policies of other health systems.ResultsTwo systematic reviews, five health technology assessment (HTA) and three Clinical Practice Guidelines (CPG) were included. One coverage policy was found.In 2012, the Canadian Agency for Drugs and Technologies in Health carried out a systematic review based on 14 studies (one systematic review and 13 observational studies) which assessed diagnostic accuracy and validity of transient elastography to detect the extent of fibrosis in patients with hepatitis C compared to biopsy. The systematic review reported that in order to predict stages of significant fibrosis (F2-F3 in METAVIR Score), test sensitivity is 50-76% and its specificity, 80-90%. Findings from observational studies revealed that for stages of significant fibrosis (F2-F3), the sensitivity was 60 to 90% and specificity, 32 to 93%. For cirrhosis (F4), sensitivity was 96 to 98% and specificity, 81 to 94%. As extent of fibrosis was higher, FibroScan® performance improved.In 2008, a systematic review was published assessing the diagnostic accuracy of transient elastography in liver fibrosis of any etiology using biopsy as the gold standard. Fifty five observational studies were included. It was observed that in advanced fibrosis and cirrhosis stages, the test had better performance.The 2007 Argentine Consensus on Hepatitis C states that there is no general agreement on the use of FibroScan® in our country. The Latin-American Association for the Study of the Liver Practice Guidelines states that FibroScan® might be useful in the selection of patients with significant fibrosis for antiviral therapy, and eventually avoid biopsy. Other HTA agencies consider that the use of FibroScan®, as an alternative method, is still under debate, mainly for mild and moderate fibrosis stages.One U.S. coverage policy considers FibroScan® as a diagnostic and monitoring method under investigation.ConclusionsThere is evidence of good methodological quality from systematic reviews and meta-analysis of observational studies on diagnostic accuracy of transient elastography compared with thegold standard: biopsy.FibroScan® seems to be a potential non-invasive diagnostic method used as an alternative to liver biopsy to diagnose and stage the degree of fibrosis. It might be useful in patients with contraindications for percutaneous biopsy and to follow-up patients with fibrosis who are under treatment. However, it has several disadvantages that may limit its reproducibility such as processes which increase or decrease liver consistency (steatosis), obesity, ascites or reduced intercostal spaces, and its low accuracy to identify mild to moderate stages of fibrosis.At present, the biopsy is still the diagnostic method of choice for the diagnosis of liver fibrosis.