Liver fibrosis occurs when
there is a lot of scar tissue in the liver. The scar tissue can result
from damage to liver cells caused by infections such as chronic
hepatitis B or C, inflammation and injury. Other causes of liver
fibrosis (not considered in this guidance) can include heavy alcohol
consumption, toxins and some rare inherited diseases.
The standard methods [1] of assessing
whether there is damage in the liver are ultrasound scans, transient
elastography, and biopsy. The draft guidance advises that VTq is as
accurate as transient elastography in diagnosing and staging liver
fibrosis, and may offer additional benefits in terms of allowing liver
imaging as well as sampling selected areas. Using VTq may also create
greater savings for hospitals where liver biopsy is the primary method
for diagnosing and monitoring liver fibrosis.
VTq is a software application which
assesses the stiffness of the liver based on readings of a high
intensity ultrasound wave which is transmitted through the liver. The
wave travels at different speeds through liver tissue depending on
whether the liver is flexible and healthy, or whether it is stiff due to
fibrous scar tissue caused by damage. The device measures the speed of
the sound waves to determine the condition of the liver tissue and
allows the liver to be imaged at the same time.
The company which manufactures the system claims that the benefits of
VTq include the procedure being painless and possibly safer than liver
biopsy, and reduced costs.
The cost modelling suggests that using VTq could save around £434 per
patient compared with liver biopsy and around £53 per patient compared
with transient elastography.
Professor Carole Longson, director of the NICE centre for health technology evaluation, said: “Liver
fibrosis can result from infections such as chronic hepatitis B and C –
conditions which affect hundreds of thousands of people in the UK.
Diagnosing and monitoring any liver damage caused by these infections is
important for ensuring that an affected person receives appropriate
care and treatment.
“This draft guidance, developed by the independent Medical
Technologies Advisory Committee (MTAC), proposes supporting VTq for
diagnosing and monitoring liver fibrosis in adults and children with
hepatitis B or C. The evidence examined by MTAC indicates that VTq may
avoid the need for surgical biopsy – which could mean no pain for the
patient, and potentially save the health service over £400 compared to
performing a biopsy. It could also be used for patients where obesity
or other factors mean that the standard form of non-invasive fibrosis
testing – transient elastography – isn’t suitable.
“MTAC also considered that VTq is likely to be used in an outpatient
setting as part of the initial referral from primary care for people who
test positive for chronic hepatitis B or C. Clinical experts advised
that there is also potential for VTq to be done in future in primary
care settings, if performed by staff with specialist training in
ultrasound imaging and its interpretation. We welcome comments on the
draft guidance during this consultation.”
More information on the medical technology draft guidance consultation for VTq is available at:
https://www.nice.org.uk/guidance/indevelopment/gid-mt210. The consultation closes on 19 January 2015.
ENDS
For more information call Dr Tonya Gillis at the NICE press office on 0300 323 0142.
Notes to Editors
Explanation of terms
[1] The standard methods
of assessing whether there is damage in the liver include ultrasound
scans, transient elastography, and biopsy. Transient elastography is a
procedure which measures the stiffness of the liver tissue based on
patterns of distortion created in the tissue when nearby skin is
vibrated. Biopsy is an invasive procedure where a small sample of liver
tissue is removed using a fine needle and then assessed for changes.
About the NICE draft guidance
1. The draft
medical technologies guidance, “Virtual Touch Quantification to diagnose
and monitor liver fibrosis”, is available at
https://www.nice.org.uk/guidance/indevelopment/gid-mt210 from 17
December 2014.
2. Virtual Touch Quantification (VTq) is manufactured by
Siemens. The VTq software application uses acoustic radiation force
impulse (ARFI) imaging technology to measure the elasticity of liver
tissue. VTq is used in combination with a Siemens Acuson S2000 or S3000
ultrasound platform. Liver tissue can be damaged by inflammation,
causing high levels of collagen to be deposited in the liver cells
(fibrosis), which become stiff. ARFI imaging involves generating a shear
wave by applying an acoustic ‘push pulse’ lateral to the area of
interest identified during a conventional ultrasound scan. The speed of
the shear wave is proportional to the stiffness of the tissue.
3. Cost modelling suggests that using VTq is cost saving compared
with transient elastography and liver biopsy, whether or not a
compatible Siemens ultrasound machine needs to be purchased. The
estimated overall cost saving per patient compared with transient
elastography, including the purchase of an ultrasound machine for which
VTq assessment of liver fibrosis accounts for 10% of the patient
throughput, is around £53. Compared with liver biopsy, the corresponding
saving is around £434.
4. The cost of the VTq software stated in the company’s
submission is £4415. A compatible Siemens Acuson S2000 ultrasound system
costs £59,700, with yearly maintenance costs, starting from year 2, of
£2246. All costs are excluding VAT.
5. In the UK, chronic hepatitis B affects an estimated 170,000 people (British Liver Trust), and around 214,000 individuals have long-term (chronic) infection with hepatitis C (Public Health England).
About the Medical Technologies Evaluation Programme
6.
The focus of Medical Technologies Evaluation Programme is specifically
on the evaluation of innovative medical technologies, including devices
and diagnostics. The types of products which might be included are
medical devices that deliver treatment such as those implanted during
surgical procedures, technologies that give greater independence to
patients, and diagnostic devices or tests used to detect or monitor
medical conditions. The independent Medical Technology Advisory
Committee has two core remits: selecting medical technologies for
evaluation by NICE guidance programmes and also developing medical
technologies guidance itself. The guidance applies to the NHS in
England, and is not mandatory.
More information is available at http://www.nice.org.uk/MT.