ReSPECT study; Assessment of the Future Remnant Liver before partial liver resection by 99mTc-mebrofenin SPECT volumetrie

Surgical resection is the most effective treatment for hepatic malignancies.
Extended resections are performed more frequently. However, the risk of
postoperative liver failure increases when too much liver is resected,
particularly in patients with coexisting parenchymal liver diseases such as
cirrhosis or steatosis. Preoperative evaluation of the function of the future
remnant liver (FRL) is therefore crucial for deciding on the extent of
resection. Current guidelines for safe resections are based on preoperatively
determined FRL volume by CT. Safe resection can be performed if the FRL volume
exceeds 30-40% of the total liver volume. In patients with coexisting
parenchymal liver disease, CT-volumetry may not represent actual liver function.
Furthermore, the importance of preoperative assessment of hepatic function has
increased because of recent availability of preoperative interventions to
increase FRL function by portal vein embolization (PVE). After PVE, it is
important to quantify hypertrophy and function of the non-embolized liver
lobes. However, few methods are available to measure regional liver function.
After partial liver resection, the liver has the unique ability to regenerate.
However the capacity of the liver to regenerate is influenced by multiple
factors. Therefore it is important to evaluate the regeneration process after a
partial hepatectomy.
Hepatobiliary scintigraphy (HBS) using 99mTc-mebrofenin is a non-invasive,
quantitative method for the evaluation of total and regional liver function. To
enable the assessment of functional volumes and improve assessment of liver
function on the segmental level, 3-dimentional 99mTc-mebrofenin Single Photon
Emission Computed Tomography (SPECT) has recently been introduced.

The aim of this study is to assess the clinical value of 99mTc-mebrofenin SPECT
for the measurement of liver functional volume in patients planned for liver
resection, in comparison to CT-volumetry. Furthermore, the significance of
liver volume in comparison to liver function, measured with HBS and SPECT is
assessed.

Patients are selected for PVE when the FRL volume is less than 30% of total
liver volume in livers with normal parenchyma, or less than 40% in livers with
compromised liver parenchyma.
Patients within the safely limits will be resected without PVE. Based on the
histopathological examination of the resection specimen, patients will be
divided retrospectively in patients with normal livers and compromised livers.
Preoperative workup includes the following parmeters: liver volume measured by
CT volumetry, liver functional volume measured by SPECT, liver function
measured by HBS and ICG clearance. Total liver volume and function, as well as
FRL function and volume is measured. After the resection, SPECT and HBS are
performed to measure actual remnant liver function and functional volume. The
preoperative estimated FRL function is compared with actual postoperative
function.
In the PVE group, a CT scan, HBS and SPECT are performed three weeks after
resection to measure the hypertrophy of the FRL. Three months after the
operation, a CT scan, HBS and SPECT are performed for the assessment of
regeneration.

Patients included in the study receive additional radiation. The additional
radiation is evaluated by the Radiation Committee. Intravenous injections
required for the HBS, and blood sampling needed for the ICG clearance tests,
cause some additional discomfort. There is a small risk of an allergic reaction
after the injection of ICG.