Comparison of Tc-99m-GSA scintigraphy with hepatic fibrosis and regeneration in patients with hepatectomy

Comparison between CT volumetry, technetium99m galactosyl-serum-albumin scintigraphy, and gadoxetic-acid-enhanced MRI to estimate the liver fibrosis stage in preoperative patients

OBJECTIVES

To compare the efficacy of computed tomography volumetry (CTV), technetium99m galactosyl-serum-albumin (99mTc-GSA) scintigraphy, and gadolinium-ethoxybenzyl-diethylenetriamine-pentaacetic-acid-enhanced MRI (EOB-MRI) in estimating the liver fibrosis (LF) stage in patients undergoing liver resection.

METHODS

This retrospective study included 91 consecutive patients who had undergone preoperative dynamic CT and 99mTc-GSA scintigraphy. EOB-MRI was performed in 76 patients. CTV was used to measure the total liver volume (TLV), spleen volume (SV), normalised to the body surface area (BSA), and liver-to-spleen volume ratio (TLV/SV). 99mTc-GSA scintigraphy provided LHL15, HH15, and GSA indices. The liver-to-spleen ratio (LSR) was calculated in the hepatobiliary phase of EOB-MRI. Hyaluronic acid and type 4 collagen levels were measured in 65 patients. Logistic regression and receiver operating characteristic (ROC) analyses were performed to identify useful parameters for estimating the LF stage and laboratory data.

RESULTS

According to the multivariable logistic regression analysis, SV/BSA (odds ratio [OR], 1.01; 95% confidence interval [CI], 1.003-1.02; p = 0.011), LSR (OR, 0.06; 95%CI, 0.004-0.70; p = 0.026), and hyaluronic acid (OR, 1.01; 95%CI, 1.001-1.02; p = 0.024) were independent variables for severe LF (F3-4). Combined SV/BSA, LSR, and hyaluronic acid correctly estimated severe LF, with an AUC of 0.91, which was significantly larger than the AUCs of the GSA index (AUC = 0.84), SV/BSA (AUC = 0.83), or LSR (AUC = 0.75) alone.

CONCLUSIONS

Combined CTV, EOB-MRI, and hyaluronic acid analyses improved the estimation accuracy of severe LF compared to CTV, EOB-MRI, or 99mTc-GSA scintigraphy individually.

CLINICAL RELEVANCE STATEMENT

The combined analysis of spleen volume on CT volumetry, liver-to-spleen ratio on gadolinium-ethoxybenzyl-diethylenetriamine-pentaacetic-acid-enhanced MRI, and hyaluronic acid can identify severe liver fibrosis associated with a high risk of liver failure after hepatectomy and recurrence in patients with hepatocellular carcinoma.

KEY POINTS

• Spleen volume of CT volumetry normalised to the body surface area, liver-to-spleen ratio of EOB-MRI, and hyaluronic acid were independent variables for liver fibrosis. • CT volumetry and EOB-MRI enable the detection of severe liver fibrosis, which may correlate with post-hepatectomy liver failure and complications. • Combined CT volumetry, gadolinium-ethoxybenzyl-diethylenetriamine-pentaacetic-acid-enhanced MRI (EOB-MRI), and hyaluronic acid analyses improved the estimation of severe liver fibrosis compared to technetium99m galactosyl-serum-albumin scintigraphy.

Assessing Liver Fibrosis Using 2D-SWE Liver Ultrasound Elastography and Dynamic Liver Scintigraphy with 99mTc-mebrofenin: A Comparative Prospective Single-Center Study

Background and Objectives: Many quantitative imaging modalities are available that quantify chronic liver disease, although only a few of them are included in clinical guidelines. Many more imaging options are still competing to find their place in the area of diagnosing chronic liver disease. We report our first prospective single-center study evaluating different imaging modalities that stratify viral hepatitis-associated liver fibrosis in a treatment-naïve patient group. Materials and Methods: The aim of our study is to compare and to combine already employed 2D shear wave elastography (2D-SWE) with dynamic liver scintigraphy with 99mTc-mebrofenin in chronic viral hepatitis patients for the staging of liver fibrosis. Results: Seventy-two patients were enrolled in the study. We found that both 2D-SWE ultrasound imaging, with dynamic liver scintigraphy with 99mTc-mebrofenin are able to stratify CLD patients into different liver fibrosis categories based on histological examination findings. We did not find any statistically significant difference between these imaging options, which means that dynamic liver scintigraphy with 99mTc-mebrofenin is not an inferior imaging technique. A combination of these imaging modalities showed increased accuracy in the non-invasive staging of liver cirrhosis. Conclusions: Our study presents that 2D-SWE and dynamic liver scintigraphy with 99mTc-mebrofenin could be used for staging liver fibrosis, both in singular application and in a combined way, adding a potential supplementary value that represents different aspects of liver fibrosis in CLD.

Combining 99mTc-GSA single-photon emission-computed tomography and Gd-EOB-DTPA-enhanced magnetic resonance imaging for staging liver fibrosis

Preoperative assessment of the degree of liver fibrosis is important to determine treatment strategies. In this study, galactosyl human serum albumin single-photon emission-computed tomography and ethoxybenzyl (EOB) contrast-enhanced magnetic resonance imaging (MRI) were used to assess the changes in hepatocyte function after liver fibrosis, and the standardized uptake value (SUV) was combined with gadolinium EOB-diethylenetriaminepentaacetic acid to evaluate its added value for liver fibrosis staging. A total of 484 patients diagnosed with hepatocellular carcinoma who underwent liver resection between January 2010 and August 2018 were included. Resected liver specimens were classified based on pathological findings into nonfibrotic and fibrotic groups (stratified according to the Ludwig scale). Galactosyl human serum albumin-single-photon emission-computed tomography and EOB contrast-enhanced MRI examinations were performed, and the mean SUVs (SUVmean) and contrast enhancement indices (CEIs) were obtained. The diagnostic value of the acquired SUV and CEIs for fibrosis was assessed by calculating the area under the receiver operating characteristic curve (AUC). In the receiver operating characteristic analysis, SUV + CEI showed the highest AUC in both fibrosis groups. In particular, in the comparison between fibrosis groups, SUV + CEI showed significantly higher AUCs than SUV and CEI alone in discriminating between fibrosis (F3 and 4) and no or mild fibrosis (F0 and 2) (AUC: 0.879, vs SUV [P = 0.008], vs. CEI [P = 0.023]), suggesting that the combination of SUV + CEI has greater diagnostic performance than the individual indices. Combining the SUV and CEI provides high accuracy for grading liver fibrosis, especially in differentiating between grades F0 and 2 and F3-4. SUV and gadolinium EOB-diethylenetriaminepentaacetic acid-enhanced MRI can be noninvasive diagnostic methods to guide the selection of clinical treatment options for patients with liver diseases.

Quantitative Assessment of Liver Impairment in Chronic Viral Hepatitis with [99mTc]Tc-Mebrofenin: A Noninvasive Attempt to Stage Viral Hepatitis-Associated Liver Fibrosis

Background and objectives—Chronic viral hepatitis B and C infections are one of the leading causes of chronic liver impairment, resulting in liver fibrosis and liver cirrhosis. An early diagnosis with accurate liver fibrosis staging leads to a proper diagnosis, thus tailoring correct treatment. Both invasive and noninvasive techniques are used in the diagnosis and staging of chronic liver impairment. Those techniques include liver biopsy, multiple serological markers (as either single tests or combined panels), and imaging examinations, such as ultrasound or magnetic resonance elastography. Nuclear medicine probes may also be employed in staging liver fibrosis, although the literature scarcely reports this. The purpose of our study was to investigate whether a dynamic liver scintigraphy with [^99mTc]Tc-mebrofenin has any value in staging or grading chronic liver damage. Materials and Methods—We prospectively enrolled patients with chronic viral hepatitis B and C infection referred for liver biopsy. All patient underwent dynamic liver scintigraphy with 99mTc-mebrofenin prior to liver biopsy. Dynamic liver scintigraphy was performed immediately after intravenous tracer injection for 30 min scanning time. Multiple scintigraphy parameters were calculated (whole liver lobe and focal area time to peak (TTP), 30 min to peak ratio (30/peak), whole lobe and focal area slope index in 350 s (slope_350). Liver biopsy took place shortly after imaging. Results—We found that many dynamic scintigraphic parameters are positively or negatively associated with different stages of liver fibrosis. The main parameters that showed most value are the ratio between 30 min and the peak of the dynamic curve (30/peak_dex (ratio)), and liver clearance corrected for body surface area and liver area (LCL_m²_dm² (%/min/m²/dm²)). Conclusions—Our present study proves that conducting dynamic liver scintigraphies with [^99mTc]Tc-mebrofenin has potential value in staging liver fibrosis. The benefits of this method, including whole liver imaging and direct imaging of the liver function, provide an advantage over presently used quantitative imaging modalities.

Prediction of liver regeneration in recipients after living-donor liver transplantation in using preoperative CT texture analysis and clinical features

PURPOSE

The aim of the study is to predict the rate of liver regeneration in recipients after living-donor liver transplantation using preoperative CT texture and shape analysis of the future graft.

METHODS

102 donor-recipient pairs who underwent living-donor liver transplantation using right lobe grafts were retrospectively included. We semi-automatically segmented the future graft from preoperative CT. The volume of the future graft (LV_pre) was measured, and texture and shape analyses were performed. The graft liver was segmented from postoperative follow-up CT and the volume of the graft (LV_post) was measured. The regeneration index was defined by the following equation: [(LV_post-LV_pre)/LV_pre] × 100(%). We performed a stepwise, multivariate linear regression analysis to investigate the association between clinical, texture and shape parameters and the RI and to make the best-fit predictive model.

RESULTS

The mean regeneration index was 47.5 ± 38.6%. In univariate analysis, the volume of the future graft, energy, effective diameter, surface area, sphericity, roundness_m, compactness1, and grey-level co-occurrence matrix contrast as well as several clinical parameters were significantly associated with the regeneration index (p < 0.05). The best-fit predictive model for the regeneration index made by multivariate analysis was as follows: Regeneration index (%) = 127.020-0.367 × effective diameter - 1.827 × roundness_m + 47.371 × recipient body surface area (m²) + 12.041 × log(recipient white blood cell count) (× 10³/μL)+ 18.034 (if the donor was female).

CONCLUSION

The effective diameter and roundness_m of the future graft were associated with liver regeneration. Preoperative CT texture analysis of future grafts can be useful for predicting liver regeneration in recipients after living-donor liver transplantation.

Modeling of Normal Tissue Complications Using Imaging and Biomarkers After Radiation Therapy for Hepatocellular Carcinoma

PURPOSE

To develop normal tissue complications (NTCP) models for hepatocellular cancer (HCC) patients who undergo liver radiation therapy (RT) and to evaluate the potential role of functional imaging and measurement of blood-based circulating biological markers before and during RT to improve the performance of these models.

METHODS AND MATERIALS

The data from 192 HCC patients who had undergone RT from 2005 to 2014 were evaluated. Of the 192 patients, 146 had received stereotactic body RT (SBRT) and 46 had received conventional RT to a median physical tumor dose of 49.8 Gy and 50.4 Gy, respectively. The physical doses were converted into 2-Gy equivalents for analysis. Two approaches were investigated for modeling NTCP: (1) a generalized Lyman-Kutcher-Burman model; and (2) a generalization of the parallel architecture model. Three clinical endpoints were considered: the change in albumin-bilirubin (ALBI), change in Child-Pugh (C-P) score, and grade ≥3 liver enzymatic changes. Local dynamic contrast-enhanced magnetic resonance imaging portal venous perfusion information was used as an imaging biomarker for local liver function. Four candidate inflammatory cytokines were considered as biological markers. The imaging findings and cytokine levels were incorporated into NTCP modeling, and their role was evaluated using goodness-of-fit metrics.

RESULTS

Using dosimetric information only, the Lyman-Kutcher-Burman model for the ALBI/C-P change had a steeper response curve compared with grade ≥3 enzymatic changes. Incorporating portal venous perfusion imaging information into the parallel architecture model to represent functional reserve resulted in relatively steeper dose-response curves compared with dose-only models. A larger loss of perfusion function was needed for enzymatic changes compared with ALBI/C-P changes. Increased transforming growth factor-β1 and eotaxin expression increased the trend of expected risk in both NTCP modeling approaches but did not reach statistical significance.

CONCLUSIONS

The incorporation of imaging findings and biological markers into NTCP modeling of liver toxicity improved the estimates of expected NTCP risk compared with using dose-only models. In addition, such generalized NTCP models should contribute to a better understanding of the normal tissue response in HCC SBRT patients and facilitate personalized treatment.

Fractal Dimension of Tc-99m DTPA GSA Estimates Pathologic Liver Injury due to Chemotherapy in Liver Cancer Patients

BACKGROUND

Chemotherapy-induced liver injury after potent chemotherapy is a considerable problem in patients undergoing liver resection. The aim of this study was to assess the relationship between the fractal dimension (FD) of Tc-99m diethylenetriaminepentaacetic acid (DTPA) galactosyl human serum albumin (GSA) and pathologic change of liver parenchyma in liver cancer patients who have undergone chemotherapy.

METHODS

We examined 34 patients (10 female and 24 male; mean age, 68.5 years) who underwent hepatectomy. Hepatic injury was defined as steatosis more than 30 %, grade 2-3 sinusoidal dilation, and/or steatohepatitis Kleiner score ≥4. Fractal analysis was applied to all images of Tc-99m DTPA GSA using a plug-in tool on ImageJ software (NIH, Bethesda, MD). A differential box-counting method was applied, and FD was calculated as a heterogeneity parameter. Correlations between FD and clinicopathological variables were examined.

RESULTS

FD values of patients with steatosis and steatohepatitis were significantly higher than those without (P > .001 and P > .001, respectively). There was no difference between the FD values of patients with and without sinusoidal dilatation (P = .357). Multivariate logistic regression showed FD as the only significant predictor for steatosis (P = .005; OR 36.5; 95 % CI 3.0-446.3) and steatohepatitis (P = .012; OR, 29.1; 95 % CI 2.1-400.1).

CONCLUSIONS

FD of Tc-99m DTPA GSA was the significant predictor for fatty liver disease in patients who underwent chemotherapy. This new modality is able to differentiate steatohepatitis from steatosis; therefore, it may be useful for predicting chemotherapy-induced pathologic liver injury.

Recent advances in estimating hepatic functional reserve in patients with chronic liver damage

Preoperative estimation of liver functional reserve is important in liver surgery to prevent postoperative liver failure. Although the hepatic functional reserve of patients with chronic liver disease is generally evaluated by measuring indocyanine green dye retention at 15 min, no standard method of estimating regional liver function has been established to date. Several recently introduced imaging modalities, such as hepatobiliary scintigraphy and magnetic resonance imaging with gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid, may be used to evaluate liver function. Here, we review recent advances in estimating hepatic functional reserve, mainly by radiological modalities, in patients with chronic liver damage.

Associated factors with surgical site infections after hepatectomy: predictions and countermeasures by a retrospective cohort study

BACKGROUND

To clarify the factors associated with post-hepatectomy surgical site infections (SSIs), the clinicopathological data of 526 patients who underwent hepatectomy was retrospectively examined as a retrospectively cohort study.

METHODS

Patient demographics, liver functions, histological findings, surgical records and post-hepatectomy morbidity were compared between non-SSI and SSI groups; the SSI group included superficial and deep SSIs.

RESULTS

The prevalence of SSIs (5-8%) has not changed over an 18-year period. Deep SSIs were significantly more increased in male patients with lower performance statuses and American Society of Anesthesiologists (ASA) scores (p < 0.05). SSIs tended to be less prevalent, although not significant (p = 0.10), in patients who underwent laparoscopic hepatectomies compared to those who underwent laparotomies. For patients in whom hemostatic devices were used, the prevalence of superficial SSIs was significantly lower than those in whom the devices were not used (p < 0.05). Blood loss and transfusion were significantly more frequent in the deep SSI group compared to other groups (p < 0.01). Hospital stay in the deep SSI group was significantly longer compared to other groups. The incidence of morbidity was more frequent in the SSI groups compared with the non-SSI group (p < 0.001). A multivariate analysis showed that not using a vessel sealing device was significantly associated with superficial SSIs; male gender, hepatic failure and bile leakage were significantly associated with deep SSIs (p < 0.05).

CONCLUSIONS

SSIs were important indicators of patient outcomes after hepatectomies, and preventing SSI development after surgical procedures is an important step in improving the overall prevalence of SSIs.

A nonhuman primate model of human radiation-induced venocclusive liver disease and hepatocyte injury

BACKGROUND

Human liver has an unusual sensitivity to radiation that limits its use in cancer therapy or in preconditioning for hepatocyte transplantation. Because the characteristic veno-occlusive lesions of radiation-induced liver disease do not occur in rodents, there has been no experimental model to investigate the limits of safe radiation therapy or explore the pathogenesis of hepatic veno-occlusive disease.

METHODS AND MATERIALS

We performed a dose-escalation study in a primate, the cynomolgus monkey, using hypofractionated stereotactic body radiotherapy in 13 animals.

RESULTS

At doses ≥40 Gy, animals developed a systemic syndrome resembling human radiation-induced liver disease, consisting of decreased albumin, elevated alkaline phosphatase, loss of appetite, ascites, and normal bilirubin. Higher radiation doses were lethal, causing severe disease that required euthanasia approximately 10 weeks after radiation. Even at lower doses in which radiation-induced liver disease was mild or nonexistent, latent and significant injury to hepatocytes was demonstrated by asialoglycoprotein-mediated functional imaging. These monkeys developed hepatic failure with encephalopathy when they received parenteral nutrition containing high concentrations of glucose. Histologically, livers showed central obstruction via an unusual intimal swelling that progressed to central fibrosis.

CONCLUSIONS

The cynomolgus monkey, as the first animal model of human veno-occlusive radiation-induced liver disease, provides a resource for characterizing the early changes and pathogenesis of venocclusion, for establishing nonlethal therapeutic dosages, and for examining experimental therapies to minimize radiation injury.

Measuring hepatic functional reserve using low temporal resolution Gd-EOB-DTPA dynamic contrast-enhanced MRI: a preliminary study comparing galactosyl human serum albumin scintigraphy with indocyanine green retention

OBJECTIVE

To investigate if tracer kinetic modelling of low temporal resolution dynamic contrast-enhanced (DCE) MRI with Gd-EOB-DTPA could replace technetium-99 m galactosyl human serum albumin (GSA) single positron emission computed tomography (SPECT) and indocyanine green (ICG) retention for the measurement of liver functional reserve.

METHODS

Twenty eight patients awaiting liver resection for various cancers were included in this retrospective study that was approved by the institutional review board. The Gd-EOB-DTPA MRI sequence acquired five images: unenhanced, double arterial phase, portal phase, and 4 min after injection. Intracellular contrast uptake rate (UR) and extracellular volume (Ve) were calculated from DCE-MRI, along with the ratio of GSA radioactivity of liver to heart-plus-liver and per cent of cumulative uptake from 15-16 min (LHL15 and LU15, respectively) from GSA-scintigraphy. ICG retention at 15 min, Child-Pugh cirrhosis score (CPS) and postoperative Inuyama fibrosis criteria were also recorded. Statistical analysis was with Spearman rank correlation analysis.

RESULTS

Comparing MRI parameters with the reference methods, significant correlations were obtained for UR and LHL15, LU15, ICG15 (all 0.4-0.6, P < 0.05); UR and CPS (-0.64, P < 0.001); Ve and Inuyama (0.44, P < 0.05).

CONCLUSION

Measures of liver function obtained by routine Gd-EOB-DTPA DCE-MRI with tracer kinetic modelling may provide a suitable method for the evaluation of liver functional reserve.

KEY POINTS

• Magnetic resonance imaging (MRI) provides new methods of measuring hepatic functional reserve. • DCE-MRI with Gd-EOB-DTPA offers the possibility of replacing scintigraphy. • The analysis method can be used for preoperative liver function evaluation.

Functional liver reserve parameters predictive for posthepatectomy complications

BACKGROUND

Posthepatectomy complications have markedly decreased with advances in techniques and management; however, surgical risk to patients with injured livers is still not negligible. We evaluated several preoperative parameters of functional liver reserve tests in patients with various liver diseases as predictors of posthepatectomy complications. A comprehensive evaluation of preoperative liver functions is necessary for the prediction of the risk of posthepatectomy complications.

METHODS

Over a 10-y period, we examined 442 patients who underwent hepatectomy for liver and biliary diseases. The patients' background liver diseases included chronic viral liver diseases in 211 patients, obstructive jaundice in 29 patients, and normal liver in 202 patients. Hepatectomy-related postoperative complications (i.e., long-term ascites, intra-abdominal infection, and hepatic failure) occurred in 115 (26%) patients. A multivariate logistic analysis was performed to detect the predictive parameters, and a multivariate linear regression analysis was performed to derive a predictive formula for complications.

RESULTS

A univariate analysis identified 15 significant parameters associated with hepatectomy-related complications, and eight parameters (i.e., presence of chronic hepatic injury, clearance index by technetium-99 m galactosyl human serum albumin liver scintigraphy of ≥ 0.60, total bilirubin level of >1 mg/dL, serum hyaluronic acid level of ≥ 75 ng/mL, major hepatectomy, blood loss of ≥ 950 mL, operating time of ≥ 500 min, and combined resection of another organ or major vessel) were independent predictive factors identified in the multivariate analysis. Clearance index by technetium-99 m galactosyl human serum albumin liver, bilirubin level, hyaluronic acid level, and major hepatectomy were the parameters included in the predictive formula.

CONCLUSIONS

In the present study, we present a comprehensive formula based on the predictive parameters for hepatic complications for prospective assessment to avoid posthepatectomy morbidity.

Hepatic radiation toxicity: avoidance and amelioration

The refinement of radiation therapy and radioembolization techniques has led to a resurgent interest in radiation-induced liver disease (RILD). The awareness of technical and clinical parameters that influence the chance of RILD is important to guide patient selection and toxicity minimization strategies. "Classic" RILD is characterized by anicteric ascites and hepatomegaly and is unlikely to occur after a mean liver dose of approximately 30 Gy in conventional fractionation. By maintaining a low mean liver dose and sparing a "critical volume" of liver from radiation, stereotactic delivery techniques allow for the safe administration of higher tumor doses. Caution must be exercised for patients with hepatocellular carcinoma or pre-existing liver disease (eg, Child-Pugh score of B or C) because they are more susceptible to RILD that can manifest in a nonclassic pattern. Although no pharmacologic interventions have yet been proven to mitigate RILD, preclinical research shows the potential for therapies targeting transforming growth factor-β and for the transplantation of stem cells, hepatocytes, and liver progenitor cells as strategies that may restore liver function. Also, in the clinical setting of veno-occlusive liver disease after high-dose chemotherapy, agents with fibrinolytic and antithrombotic properties can reverse liver failure, suggesting a possible role in the setting of RILD.

Hepatobiliary function assessed by 99mTc-mebrofenin cholescintigraphy in the evaluation of fibrosis in chronic hepatitis: histopathological correlation

PURPOSE

Although liver biopsy remains the gold standard in the staging of liver fibrosis in chronic hepatitis C virus (HCV) infection, several noninvasive methods are under evaluation for clinical use. The aim of this study was to evaluate the utility of hepatobiliary function through technetium-99m-N-(-3-bromo-2,4,6-trimethylacetanilide) iminodiacetic acid (Tc-mebrofenin) scintigraphy in evaluating liver fibrosis in patients with chronic HCV infection.

METHODS

We studied 62 patients with HCV (18 men, 44 women). The patients were allocated into three groups according to histopathological score: group 1: portal/periportal fibrosis (21 patients; eight men, 13 women); group 2: bridging fibrosis (23 patients; seven men, 16 women); and group 3: incomplete/complete cirrhosis (18 patients; three men, 15 women). As a control group, 20 healthy volunteers (six men and 14 women) were studied. Hepatocyte mebrofenin uptake rate, the time required for maximal hepatic activity (Tmax), and the time required for peak activity to decrease by 50% (T1/2max) were calculated using Tc-mebrofenin cholescintigraphy. Scintigraphic parameters were correlated with biochemical parameters and liver histopathology.

RESULTS

The uptake rates were significantly decreased in all groups with fibrosis compared with the controls (P<0.05). The correlation between the severity of fibrosis and Tc-mebrofenin uptake rate was strongly significant (r=-0.81, P<0.0001). Tmax and T1/2max were significantly prolonged in groups 2 and 3 compared with the controls. Histopathology score was correlated moderately with Tmax and T1/2max (r=0.61, P<0.0001 and r=0.52, P<0.0001, respectively).

CONCLUSION

The assessment of hepatobiliary function by Tc-mebrofenin scintigraphy may be a good choice for assessing the severity of liver fibrosis in patients with HCV.

Nuclear imaging techniques for the assessment of hepatic function in liver surgery and transplantation

This review describes the application of 2 nuclear imaging techniques for assessment of hepatic function in the setting of liver surgery and transplantation. The biochemical and technical background, as well as the clinical applications, of (99m)Tc-labeled diethylenetriaminepentaacetic acid galactosyl human serum albumin (GSA) scintigraphy and hepatobiliary scintigraphy (HBS) with (99m)Tc-labeled iminodiacetic acid derivates is discussed. (99m)Tc-mebrofenin is considered the most suitable iminodiacetic acid agent for (99m)Tc-HBS. (99m)Tc-GSA scintigraphy and (99m)Tc-mebrofenin HBS are based on 2 different principles. (99m)Tc-GSA scintigraphy is a receptor-mediated technique whereas HBS represents hepatic uptake and excretion function. Both techniques are noninvasive and provide visual and quantitative information on both total and regional liver function. They can be used for preoperative assessment of future remnant liver function, follow-up after preoperative portal vein embolization, and evaluation of postoperative liver regeneration. In liver transplantation, these methods are used to assess graft function and biliary complications.

Relationship between 99mTc-GSA scintigraphic indices of liver function reserve and portal circulation in patients with chronic liver disease

OBJECTIVES

In order to predict the prognosis or complications of portal hypertension in patients with chronic liver disease, it is important to evaluate both hepatic functional reserve and portal circulation. On (99m)Tc-galactosyl human serum albumin ((99m)Tc-GSA) scintigraphy, the index of blood clearance (HH15) and receptor index (LHL15) have been widely used to evaluate the hepatic functional reserve. However, the relationship between these indices and portal circulation is unknown. The purpose of this study was to examine the relationship between HH15 and LHL15 and portosystemic shunts evaluated with arteriographic portography or esophagogastroduodenoscopy.

METHODS

A total of 82 patients with chronic liver disease (mean age, 66.7 years) who underwent (99m)Tc-GSA scintigraphy, arteriographic portography, and esophagogastroduodenoscopy were enrolled. HH15 and LHL15 were obtained from dynamic (99m)Tc-GSA scintigraphy. The patients were divided into three groups according to the arteriographic portography findings: group 1, no portal collateral circulation; group 2, mild collateral development; and group 3, moderate to severe collateral development. They were also divided into three groups based on the esophagogastroduodenoscopic findings: group A, no varices; group B, small-caliber varices; and group C, enlarged varices. The Kruskal-Wallis test was used to compare each index among these groups. Receiver operating characteristic (ROC) analysis was used to determine whether each index was an indicator for the presence of portosystemic shunts.

RESULTS

Both HH15 and LHL15 differed significantly between groups 1 and 2 and between groups 1 and 3. However, only HH15 differed significantly between groups A and B and between groups A and C. On the basis of the ROC analysis, the HH15 threshold value of 0.62 yielded both excellent sensitivity (83.9%) and specificity (84.6%) for the presence of portosystemic shunts, as evaluated with arteriographic portography. The HH15 threshold value of 0.64 yielded both good sensitivity (66.1%) and specificity (69.2%) for the presence of portosystemic shunts, as evaluated with esophagogastroduodenoscopy, whereas no adequate threshold value of LHL15 was found for the presence of portosystemic shunts.

CONCLUSIONS

HH15 is a potent indicator of the presence of portosystemic shunts in chronic liver disease.

Preoperative evaluation using asialoscintigraphy in patients undergoing cardiac surgery with noncardiac liver cirrhosis

OBJECTIVE

Liver cirrhosis is recognized as one of the risk factors for severe complications after cardiac surgery. However, there are no established methods for risk stratification of the patients with liver cirrhosis (LC) regarding cardiac surgery. We present our experience of preoperative evaluation of liver function using asialoscintigraphy.

METHODS

Between April 1999 and December 2005, we evaluated preoperative liver function using asialoscintigraphy with technetium-99m galactosyl human serum albumin in four cirrhotic patients undergoing coronary artery bypass grafting (n = 2) and valve replacement (n = 2), whose etiologies of LC were alcohol abuse (n = 1) and hepatitis C virus infection (n = 3). They also underwent other tests for preoperative evaluation of liver function, including the indocyanine green (ICG) test.

RESULTS

Asialoscintigraphy revealed that the receptor index and the index of blood clearance in each patient were 0.81/0.73, 0.95/0.5, 0.82/0.62, and 0.97/0.57, respectively. These values closely correlated with the results of the ICG test. All patients were discharged alive from hospital after surgery. However, although one patient who underwent off-pump bypass had an uneventful course, three patients had major complications: pleural effusion (n = 1) and wound infection (n = 2).

CONCLUSION

Asialoscintigraphy is a practical, reliable method that can replace the ICG test for estimating hepatic function for risk stratification of cirrhotic patients undergoing cardiac surgery, whose mortality and morbidity are still high.

Noninvasive evaluation of liver disease severity

In assessing the severity of chronic liver disease, one measures either the fibrotic structure of the liver or liver function. This article reviews the methods for evaluating the severity of liver disease noninvasively by estimating function or structure.