Background and Aims: Existing studies have shown that hepatic vascular involvement and tumor compression are closely related to the decline of regional liver function. Dynamic SPECT/CT 99mTc-galactosyl-human serum albumin (GSA) imaging has been proved to be a more accurate technique for regional assessment of liver function. Previous studies have used this technique to elucidate the changes of regional liver function after vascular involvement, but there is still a lack of quantitative research on the effect of tumor mechanical compression on regional liver function. The purpose of this study was to investigate the effect of mechanical compression of tumor on the function of its adjacent liver tissue.
Methods: The SPECT/CT imaging and clinical data of 45 patients with primary liver cancer were retrospectively analyzed. Of the patients, 14 patients had vascular or biliary invasion or received liver radiotherapy (affected group), and 31 patients had no such situations (non-affected group). After the corresponding areas at 2, 4 and 6 cm from the edge of the tumor (D1, D2, D3) and hemihepatic lobe regions on the CT images were drawn, the morphological liver volume (MLV) of above areas were calculated. Functional liver volume (FLV), functional liver density (FLD) and hepatocyte uptake rate constant (GSA-K) of bilateral lobes and D1-D3 regions were calculated after further fusion of SPECT image and CT image. The relevant variables of liver lobes in affected group and of D1-D3 regions within the two groups were compared. Correlation analysis and multiple linear regression analysis were used to analyze the influencing factors of the function of liver tissue adjacent to primary liver cancer.
Results: In the affected group, the FLV and FLD of tumor-bearing lobe were significantly lower than those of the other side (both P<0.01); the FLD of D1 region in non-affected group was significantly lower than that in the D2 and D3 regions (both P<0.01). The results of correlation analysis showed that tumor diameter and tumor volume were related factors affecting the FLD of D1 region in the non-affected group (both P<0.05); Child-Pugh grade was related factor influencing FLD of D2 region in the non-affected group (P<0.05). The result of multiple linear regression analysis showed that tumor diameter was the main factor affecting FLD of D1 region in non-affected group (P<0.05).
Conclusion: The mechanical compression of tumor may be an important factor affecting the function of liver tissue adjacent to primary liver cancer and thereby leading to the decline of regional liver function. When the tumor diameter is large, the risk of hepatectomy may be overestimated in patients with marginal reserved liver volume, which affects the choice of treatment for such patients.