Recent Advances in Functional Liver Volumetry: Emphasis on 99mTc-GSA SPECT/CT Fusion Imaging

Area of Science:

• Hepatobiliary Surgery
• Medical Imaging
• Nuclear Medicine

Background:

• Assessing future liver remnant (FLR) function is crucial for major hepatectomy safety.
• Computed tomography (CT) volumetry alone inadequately reflects functional capacity, especially in patients with liver disease or prior therapy.
• Quantitative assessment of regional liver function is needed to predict outcomes.

Purpose of the Study:

• To review advances in functional liver volumetry, focusing on 99mTc-GSA SPECT/CT.
• To highlight the clinical applications of functional imaging in major hepatectomy.
• To emphasize the predictive value of functional volumetry over volumetric assessment alone.

Main Methods:

• Utilizing technetium-99m-labeled galactosyl human serum albumin (99mTc-GSA) scintigraphy.
• Employing single-photon emission computed tomography/computed tomography (SPECT/CT) fusion imaging for quantitative assessment.
• Correlating functional imaging findings with volumetric data and clinical outcomes.

Main Results:

• Functional liver volumetry with 99mTc-GSA SPECT/CT provides superior prediction of post-hepatectomy liver failure compared to CT volumetry.
• Functional imaging reveals that liver regeneration (functional recovery) often precedes or exceeds volumetric hypertrophy after procedures like PVE and ALPPS.
• Factors including liver fibrosis, chemotherapy, and hepatic venous congestion impact regional functional recovery.

Conclusions:

• Functional liver volumetry with 99mTc-GSA SPECT/CT enables simultaneous evaluation of FLR volume and function.
• This method improves risk stratification and surgical decision-making in major hepatectomy planning.
• Integrating functional imaging enhances the safety and outcomes of liver surgery.