Liver function assessment using 99mTc-GSA single-photon emission computed tomography (SPECT)/CT fusion imaging in hilar bile duct cancer: A retrospective study

Regional Liver Function Assessment Using 99mTc-GSA SPECT/CT Scintigraphy in Malignant Perihilar Biliary Tumor Undergoing Major Liver Resection: A Dual-Center Cohort Study

BACKGROUND

Cholestasis can lead to unreliable results of routine liver function assessment tests in clinical practice and the functional cutoff value of hepatectomy is still unclear. The aim of this study was to determine which 99mTc-GSA scintigraphy functional indicators can predict post-hepatectomy liver failure (PHLF) in patients before major liver resection due to malignant perihilar biliary disease. In addition, it aimed to assess the efficiency of functional future liver remnant (FLR) assessment of 99mTc-GSA scintigraphy indicators.

PATIENTS AND METHODS

A 99mTc-GSA scintigraphy was performed prior to planned surgery in 187 patients, including 81 patients with major liver resection. The 99mTc-GSA scintigraphy parameters including functional liver volume (FLV), ratio of the FLR functional volume to body weight (FLVFLR-BWR), and predictive residual index (PRI) were calculated from radioactive count in regions of FLR and total liver (TOTAL). Morphological liver volume (MLV) was calculated from computed tomography and standardized by standard liver volume (SLV). The efficacy of these parameters in predicting PHLF was compared using generalized linear mixed models and receiver operating characteristic (ROC) curve analysis.

RESULTS

PHLF occurred in 22 patients, who showed lower MLVFLR/SLV, FLVFLR, FLVFLR/FLVTOTAL, FLVFLR-BWR, and PRI and higher resection rate (P < 0.05 for all) than patients without PHLF. After adjusting for clinical parameters, a decreased FLVFLR-BWR (odds ratio, OR 0.17; 95% confidence intervals, CI 0.05-0.53) was found to be an independently significant indicator in the model of GLMM. FLVFLR-BWR (0.835) had the highest ROC among all liver functional indicators.

CONCLUSIONS

The FLR functional parameter preoperatively estimated from preoperative 99mTc-GSA scintigraphy protocol is a promising tool for regional liver function assessment, and it can distinguish high-risk patients who may develop PHLF with malignant perihilar biliary tumor undergoing major liver resection.

New criteria for preoperative liver function assessment with safety margins to avoid postoperative mortality during liver resection for hilar cholangiocarcinoma

BACKGROUND

Despite recent medical advancements, surgery for hilar cholangiocarcinoma is associated with high complication and mortality rates. This may be partly attributed to the absence of established preoperative liver evaluation criteria for safe surgery. This study aimed to propose a reliable indicator for safe and well-planned management of major hepatectomy with extrahepatic bile duct resection.

METHODS

We included 150 patients who underwent major hepatectomy with extrahepatic bile duct resection between 2013 and 2021 in Japan. The risk factors for post-hepatectomy liver failure (PHLF) were retrospectively analyzed.

RESULTS

PHLF was observed in 24 (16.0 %) patients who underwent major hepatectomy with extrahepatic bile duct resection. In the multivariate analysis, the identified risk factors for PHLF were the ratio of future remnant liver volume to total liver volume (FRLV/TLV) ≤ 42 % and indocyanine green clearance fraction of the future remnant liver (ICGK-F) ≤ 0.07. Patients with these two factors were significantly associated with PHLF compared with those with either one or none of the risk factors (60.0 % vs 15.1 % and 8.1 %, respectively).

CONCLUSION

The combinational use of ICGK-F and FRLV/TLV is useful for preoperative liver function assessment with a safety margin to avoid PHLF and postoperative mortality in hepatectomy for hilar cholangiocarcinoma.

Hepatobiliary scintigraphy with SPECT/CT

Hepatobiliary scintigraphy with single-photon emission computed tomography (SPECT) is an essential Nuclear Medicine exam for assessing hepatobiliary abnormalities and planning therapy. We aim to offer a thorough and all-encompassing analysis of hepatobiliary imaging with SPECT to emphasize the practicality, precision in diagnosis, surgical or transplant planning, and advanced uses of SPECT/CT in assessing hepatobiliary disease. Readers can anticipate acquiring a comprehensive understanding of the subsequent facets. The manuscript will explore in detail the diverse clinical uses of SPECT/CT imaging in hepatobiliary system, recent technological breakthroughs in SPECT/CT imaging techniques, specifically addressing quantitative analysis methodologies, and the integration of SPECT/CT with other imaging modalities. This article will provide readers with information on current research trends and future prospects in SPECT/CT imaging for hepatobiliary applications, such as strategies for monitoring therapy, the use of artificial intelligence and machine learning for quantitative imaging biomarkers, how these advanced techniques influence patient care, treatment choices, and prognostic predictions. The goal of the review is to help the readers acquire useful knowledge about the latest hepatobiliary SPECT/CT imaging, their clinical applications, and their prospective contribution to the advancement.

99mTc-GSA scintigraphy and modified albumin-bilirubin score can be complementary to ICG for predicting posthepatectomy liver failure

BACKGROUND

Posthepatectomy liver failure (PHLF) remains a severe complication after liver resection. This retrospective study investigated the correlation of three hepatic functional tests and whether 99mTc-galactosyl human serum albumin (99mTc-GSA) scintigraphy and modified albumin-bilirubin (ALBI) score are useful for predicting PHLF.

METHODS

This retrospective cohort study included 413 consecutive patients undergoing hepatectomies between January 2017 and December 2020. To evaluate preoperative hepatic functional reserve, modified ALBI grade, indocyanine green clearance (ICG-R15), and 99mTc-GSA scintigraphy (LHL15) were examined before scheduled hepatectomy. Based on a retrospective chart review, multivariable logistic regression analysis adjusted for confounding factors was performed to confirm that mALBI, ICG-R15, and LHL15 are independent risk factors for PHLF.

RESULTS

ICG-R15 and LHL15 were moderately correlated (r =  - 0.61) but this correlation weakened when ICG-R15 was about ≥ 20. Weak correlations were observed between LHL15 and ALBI score (r =  - 0.269) and ALBI score and ICG-R15 (r = 0.339). Of 413 patients, 66 (19%) developed PHLF (20 grade A, 44 grade B, 2 grade C). Multivariable logistic regression analyses, major hepatectomy (P < 0.001), mALBI grade (P = 0.01), ICG-R15 (P < 0.001), and Esophagogastric varices (P = 0.007) were significant independent risk factors for PHLF. Subgroup analysis showed that ICG-R15 < 19, major hepatectomy, and mALBI grade and ICG-R15 ≥ 19, major hepatectomy, LHL15, and Esophagogastric varices were significant independent risk factors for PHLF (P = 0.033, 0.017, 0.02, 0.02, and 0.001, respectively).

CONCLUSION

LHL15, the assessment of Esophagogastric varices, and mALBI grade are complementary to ICG-R15 for predicting PHLF risk.

Impact of Clinically Relevant Posthepatectomy Liver Failure Predicted by Preoperative Evaluation of Functional Remnant Hepatic Reserve

Background

Few studies have investigated the remnant hepatic functional reserve before hepatectomy by calculating the functional remnant liver rate (RLR) using three-dimensional computed tomography (3D-CT)/technetium-99m-diethylenetriamine-pentaacetic acid galactosyl human serum albumin (99mTc-GSA) single-photon emission CT (SPECT) fusion imaging. We aimed to preoperatively evaluate the predictive value of functional remnant liver rate (RLR) and indocyanine green (ICG) disappearance rate (KICG) in determining the occurrence of posthepatectomy liver failure (PHLF).

Summary of Background Data

The conventional method of volumetric rem-KICG calculated from remnant liver volume and the KICG is difficult to accurately reflect heterogenous remnant liver function.

Methods

In total, 106 patients who underwent major hepatectomy were retrospectively analysed. Of these, 24 (22.6%) developed clinically relevant PHLF grades B/C. We examined the ICG retention rate at 15 min (ICGR15) and KICG and constructed a 3D-CT/99mTc-GSA SPECT fusion image to calculate the volumetric RLR, functional RLR, volumetric rem-KICG, and functional rem-KICG.

Results

The multivariate analysis showed functional rem-KICG as the strongest independent risk factor for PHLF grade B/C. The functional-to-volumetric RLR ratios in the patients with portal vein obstruction and/or tumor volume of ≥500 mL was significantly higher. The volumetric rem-KICG determined that hepatectomy was unsafe in 7 patients, whereas the functional rem-KICG determined that it was unsafe in 3 patients.

Conclusions

Functional rem-KICG was more reliable than volumetric rem-KICG in predicting clinically relevant PHLF grade B/C, as the resected side’s hepatic status highly influenced the function of the remnant liver. This finding could lead to a wider application of this technique.

Cholangiocarcinoma imaging: from diagnosis to response assessment

Cholangiocarcinoma (CCA), a highly aggressive primary liver cancer arising from the bile duct epithelium, represents a substantial proportion of hepatobiliary malignancies, posing formidable challenges in diagnosis and treatment. Notably, the global incidence of intrahepatic CCA has seen a rise, necessitating a critical examination of diagnostic and management strategies, especially due to presence of close imaging mimics such as hepatocellular carcinoma (HCC) and combined hepatocellular carcinoma-cholangiocarcinoma (cHCC-CCA). Hence, it is imperative to understand the role of various imaging modalities such as ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI), elucidating their strengths, and limitations in diagnostic precision and staging accuracy. Beyond conventional approaches, there is emerging significance of functional imaging tools including positron emission tomography (PET)-CT and diffusion-weighted (DW)-MRI, providing pivotal insights into diagnosis, therapeutic assessment, and prognostic evaluation. This comprehensive review explores the risk factors, classification, clinical features, and role of imaging in the holistic spectrum of diagnosis, staging, management, and restaging for CCA, hence serving as a valuable resource for radiologists evaluating CCA.

Quantitative analysis of liver standardized uptake value repeatability in SPECT/CT implications for clinical practice

Purpose. The aim of this study was to assess the repeatability of the SUV normalized by liver volume (SUVL) between two liver receptor SPECT/CT studies performed on different days in patients with ICG-R15 values within normal range.Methods. 935 patients who underwent liver receptor scintigraphy between January 2010 and August 2018 were included. Patients who underwent liver resection, hepatic arterial embolization or had ICG-R15 >10% between scans were excluded, and 38 patients were finally included in the analysis. The repeatability of SUVL between scans was assessed using the intraclass correlation coefficient (ICC) (1.1) between SUVLmax, SUVLpeak and SUVLmean at the first and second scan and the additive and proportional errors from the Bland-Altman analysis.Results. In ICC (1,1), SUVLmax, SUVLpeak and SUVLmean were all greater than 0.8, indicating almost perfect repeatability; neither additive nor proportional errors were observed in the Bland-Altman analysis.Conclusions. In patients with ICG-R15 values within the normal range, the SUV Liver (SUVL) between two liver receptor SPECT/CT studies performed on different days was repeatability over time. It was suggested that the SUVL of liver receptor scintigraphy could be an indicator that could be used for follow-up over time in the assessment of liver fibrosis.

Stereotactic Body Radiation Therapy (SBRT) for Hepatocellular Carcinoma (HCC) With Single Photon Emission Computed Tomography (SPECT) Functional Treatment Planning in Patients With Advanced Hepatic Cirrhosis

Purpose

We report on the feasibility and outcomes of liver stereotactic body radiation therapy (SBRT) for hepatocellular carcinoma (HCC) with single-photon emission computed tomography (SPECT) functional treatment planning in patients with Child-Pugh (CP) B/C cirrhosis.

Methods and Materials

Liver SPECT with 99mTc-sulfur colloid was coregistered to treatment planning computed tomography (CT) for the guided avoidance of functional hepatic parenchyma during SBRT. Functional liver volumes (FLVs) obtained from SPECT were compared with anatomic liver volumes defined on the planning CT. Radiation dose constraints were adapted exclusively to FLV. Local control, toxicity, and survival were reported with at least 6 months of radiographic follow-up. Pre- and posttransplant outcomes were analyzed in a subset of patients who completed SBRT as a bridge to liver transplant. Model of End-Stage Liver Disease was used to score hepatic function before and after SBRT completion.

Results

With a median follow-up of 32 months, 45 patients (58 lesions) with HCC and CP-B/C cirrhosis received SBRT to a median dose of 45 Gy (3-5 fractions). FLV loss (34%, P < .001) was observed in all patients, and the functional and anatomic liver volumes matched well in a control group of noncirrhotic/non-HCC patients. Despite marked functional parenchyma retraction, the amount of FLV on SPECT exposed to the threshold irradiation was significantly less than the CT liver volumes (P < .001) because of the optimized beam placement during dosimetry planning. Twenty-three patients (51%) successfully completed orthotopic liver transplant, with a median time to transplant of 9.2 months. With 91% in-field local control, the overall 2-year survival was 65% (90% after the orthotopic liver transplant), with no incidence of radiation-induced liver disease observed within 3 to 4 months or accelerated CP class migration from B to C within the first 6 months post-SBRT. Mean Model of End-Stage Liver Disease-Na score was not significantly elevated at 3-month intervals after SBRT completion.

Conclusions

Functional treatment planning with 99mTc sulfur colloid SPECT/CT allows identification and avoidance of functional hepatic parenchyma in patients with CP-B/C cirrhosis, leading to low toxicity and satisfactory transplant outcomes.

Essential updates 2021/2022: Update in surgical strategy for perihilar cholangiocarcinoma

Resection is the only potential curative treatment for perihilar cholangiocarcinoma (PHC); however, complete resection is often technically challenging due to the anatomical location. Various innovative approaches and procedures were invented to circumvent this limitation but the rates of postoperative morbidity (20%-78%) and mortality (2%-15%) are still high. In patients diagnosed with resectable PHC, deliberate and coordinated preoperative workup and optimization of the patient and future liver remnant are crucial. Biliary drainage is recommended to relieve obstructive jaundice and optimize the clinical condition before liver resection. Biliary drainage for PHC can be performed either by endoscopic biliary drainage or percutaneous transhepatic biliary drainage. To date there is no consensus about which method is preferred. The volumetric assessment of the future remnant liver volume and optimization mainly using portal vein embolization is the gold standard in the management of the risk to develop post hepatectomy liver failure. The improvement of systemic chemotherapy has contributed to prolong the survival not only in patients with unresectable PHC but also in patients undergoing curative surgery. In this article, we review the literature and discuss the current surgical treatment of PHC.

Safety and efficacy of neoadjuvant chemotherapy based on our resectability criteria for locally advanced perihilar cholangiocarcinoma

PURPOSE

Neoadjuvant chemotherapy (NAC) is not commonly used for perihilar cholangiocarcinoma (PHC). This study evaluated the safety and efficacy of NAC for PHC.

METHODS

Ninety-one PHC patients without metastases were treated at our department. Patients were classified as resectable (R), borderline resectable (BR), or locally advanced unresectable (LA). Upfront surgery (US) was performed for R-PHC patients without regional lymph node metastases (LNM) or those unable to tolerate NAC. The NAC regimen comprised two courses of gemcitabine-based chemotherapy for advanced PHC: R-PHC with LNM, BR, and LA.

RESULTS

US and NAC were performed on 32 and 59 patients, respectively. For US, 31 patients underwent curative intent surgery (upfront-CIS). NAC caused adverse effects in 10/59 (17%), allowed 36/59 (61%) to undergo curative intent surgery (NAC-CIS) without impairing liver function, and spared 23/59 (39%) from undergoing resection (NAC-UR). Overall survival was better in the upfront-CIS and NAC-CIS groups than in the NAC-UR group (MST: 74 vs 57 vs 17 months, p < 0.001). In 59 NAC patients, tumour size response occurred in 11/11 (100%) of R, 22/33 (66.7%) of BR, and 9/15 (60.0%) of LA patients. The un-resection rate was the highest in the LA group (27% [3/11] than in R, 30% [10/33] in BR, and 67% [10/15] in LA, p = 0.039). Multivariate analyses revealed that LA and age were independent risk factors for non-resection after NAC.

CONCLUSION

was safe and contributed to improving survival in advanced PHC patients. R-PHC was responsive to NAC, but LA remains a risk factor for non-resection through NAC.

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.

Increased future liver function after modified associating liver partition and portal vein ligation/embolization for staged hepatectomy

Background

The increasing ratio of functional future liver remnant (functional %FLR) after modified associating liver partition and portal vein ligation/embolization for staged hepatectomy (modified-ALPPS) compared with portal vein embolization (PVE) has not been comprehensively evaluated.

Purpose

To compare the increasing ratio of functional %FLR between modified-ALPPS and PVE via technetium-99 m-galactosyl human serum albumin single-photon emission computed tomography (^99mTc-GSA SPECT/CT) fusion imaging.

Material and Methods

Seven and six patients underwent modified-ALPPS (modified-ALPPS group) and PVE (PVE group) from 2015 to 2019. The functional %FLR on 99 mTc-GSA SPECT/CT fusion imaging was assessed before and 1 week (modified-ALPPS group) and 3 weeks (PVE group) after each procedure. The increasing ratio of functional %FLR (functional %FLR ratio) was calculated and compared between the two groups. Moreover, the hypertrophy ratio of future liver remnant volume (FLRV ratio) and atrophy ratio of embolized liver volume (.ELV ratio) were evaluated.

Results

The mean functional %FLR ratios of the modified-ALPPS group (1.47 ± 0.15) and the PVE group (1.49 ± 0.20) were comparable (p > .05). The median FLRV ratio of modified-ALPPS group (1.48) was higher than that of the PVE group (1.16), the median ELV ratio of the PVE group (0.81) was lower than that of the modified-ALPPS group (0.94), and the results significantly differed between the two groups (p < .05).

Conclusion

The increasing ratio of functional %FLR was comparable between modified-ALPPS and PVE. Compared with PVE, ALPPS was associated with a higher hypertrophy rate of the remnant liver but a lower atrophy rate of the embolized liver.

99mTc-GSA scintigraphy for assessing the functional volume ratio of the future liver remnant in the routine practice of liver resection

Background

The significance of incorporating regional functional heterogeneity assessment by liver scintigraphy into the calculation of the future liver remnant has been reported. However, liver scintigraphy entails additional costs and radiation exposure. Nevertheless, studies describing when liver scintigraphy demonstrates an actual benefit over computed tomography liver volumetry are lacking. Thus, we evaluated the degree of agreement between future liver remnant % values calculated by technetium ^99mTc diethylenetriaminepentaacetic acid-galactosyl human serum albumin scintigraphy (galactosyl human serum albumin–based future liver remnant %) and those by computed tomography volumetry and investigated the practical impact of performing regional functional heterogeneity assessment.

Methods

The Bland–Altman method was used to retrospectively analyze the agreement between computed tomography– and galactosyl human serum albumin–based future liver remnant % measurements in 84 patients.

Results

In ordinary patients with a computed tomography–based future liver remnant % greater than 50%, there was a good agreement between both measurements. However, in cases with a computed tomography–based future liver remnant % less than 40%, galactosyl human serum albumin–based measurements were significantly smaller than computed tomography–based values, with 88% of these patients exhibiting a galactosyl human serum albumin–based future liver remnant % less than 30%. After portal vein embolization, galactosyl human serum albumin–based measurements were primarily greater than or in agreement with computed tomography–based values, even in cases with a computed tomography–based future liver remnant % less than 40%.

Conclusion

Adding ^99mTc diethylenetriaminepentaacetic acid-galactosyl human serum albumin scintigraphy to computed tomography liver volumetry is advised when deciding on hepatectomy in patients with a computed tomography–based future liver remnant % less than 50%. If the computed tomography–based future liver remnant % is smaller than 40%, it is strongly recommended to check future liver remnant % by ^99mTc diethylenetriaminepentaacetic acid-galactosyl human serum albumin scintigraphy. In other cases, computed tomography–based future liver remnant % calculation alone can be regarded as the gold standard of safe hepatectomy.

Impact of Combined Vascular Resection and Reconstruction in Patients with Advanced Perihilar Cholangiocarcinoma

BACKGROUND

Perihilar cholangiocarcinoma often involves the adjacent vasculature, including the portal vein and hepatic artery. Combined vascular resection and reconstruction of the portal vein is more common than vascular resection and reconstruction of the hepatic artery. Herein, we aimed to elucidate the long-term outcomes in patients who underwent vascular resection and reconstruction for perihilar cholangiocarcinoma.

METHODS

Between January 2004 and December 2020, 106 patients with perihilar cholangiocarcinoma were grouped into the no resection (n = 58), resection-portal vein (n = 31), and resection-hepatic artery with or without that of portal vein (n = 17) groups.

RESULTS

There were no significant differences in morbidity and mortality between the three groups. The resection-portal vein and resection-hepatic artery groups had a significantly higher number of advanced tumors than the no resection group, but no significant differences were detected in the rates of lymph node metastasis and R0 resection between the three groups. The 5-year disease-specific survival in the resection-portal vein (37.6%) and resection-hepatic artery (26.9%) groups were poorer than that in the no resection group (47.8%), although the former groups had a significantly better prognosis than the latter group (7.0%). Multivariate analysis identified high preoperative carcinoembryonic antigen level (>5.7 ng/mL), intrahepatic metastasis, and non-R0 resection as independent poor prognostic factors.

CONCLUSION

Although the perioperative course in the resection-portal vein and hepatic artery groups was similar to that in the no resection group, the long-term prognoses were poor in the resection-portal vein and hepatic artery groups. Pre- and postoperative multidisciplinary therapy is required for patients with vascular resection and reconstruction.

Is surgery justified for elderly patients with extrahepatic cholangiocarcinoma? Reappraisal from a viewpoint of comorbidity and organ function

PURPOSE

The benefit of surgery for older patients with extrahepatic cholangiocarcinoma (EHCC) has not been established and the differences in the general condition of younger vs. older patients remain unclear.

METHODS

Patients who underwent curative surgery for EHCC were divided into two groups according to age: those younger than 75 years old (younger group) and those aged 75 years or older (older group). We analyzed the clinical data of the two groups retrospectively.

RESULTS

Among the 116 patients analyzed, 45 (38.8%) were in the older group. Regarding comorbidity, only cardiac disease was significantly more common in the older patients; however, the cardiac function of the two groups was identical. There were no significant differences in the prevalence of kidney and lung disease, but renal function was significantly deteriorated and the incidence of the mixed ventilatory defect was significantly greater in the older group. The overall 5-year survival rates for the younger and older groups were 52.4% vs. 50.4% of all cholangiocarcinoma patients (p = 0.458), 42.4% vs. 51.3% of those with hilar cholangiocarcinoma (p = 0.718), and 69.0% vs. 49.1% of those with distal cholangiocarcinoma (p = 0.534), respectively.

CONCLUSIONS

Improved survival after surgery can be expected in well-selected older cholangiocarcinoma patients. Comorbidities were not necessarily reflected in organ function, with precise organ function assessment being more important when selecting surgical candidates.

Predicting Post-Hepatectomy Liver Failure Using Intra-Operative Measurement of Indocyanine Green Clearance in Anatomical Hepatectomy

BACKGROUND

Prediction of post-hepatectomy liver failure (PHLF) based on remnant liver function reserve is important for successful hepatectomy. The aim of this study was to investigate whether intraoperative indocyanine green (ICG) clearance in a future remnant liver was a predictor of PHLF.

METHODS

This prospective study enrolled 31 consecutive patients who underwent anatomical hepatectomy between June 2016 and August 2019. Intraoperative ICG plasma disappearance rate (ICG-PDR) and ICG retention rate at 15 min (ICG-R15) were measured after clamping the selective hepatic inflow to the liver to be resected. The discriminative performance of the ICG-associated variables for the prediction of PHLF grade B/C was evaluated by receiver operator curve (ROC) analysis.

RESULTS

Of the operations performed, 87.1% were major hepatectomy. PHLF Grade B/C was observed in eight patients (25.8%) with no mortality. The concordance indices of intraoperative ICG-PDR and ICG-PDR for predicting PHLF were 0.834 (95% CI, 0.69-0.98) and 0.834 (95% CI, 0.69-0.98), respectively. A subgroup analysis of patients with preoperative biliary drainage (BD) (n = 17) showed that the concordance indices of intraoperative ICG-PDR increased to 0.923 (95% CI, 0.79-1.00).

CONCLUSIONS

Intraoperative ICG clearance in the remnant liver was a promising predictor for PHLF in patients undergoing anatomical hepatectomy, especially in patients with BD.

[Magnetic resonance imaging in liver function analysis. Modern objective reality]

Chronic liver disease is a serious worldwide problem because its progression is accompanied by liver fibrosis and cirrhosis at the terminal stages. Primary diagnosis and dynamic assessment of liver fibrosis are essential to determine the prognosis of disease and optimal treatment strategy. Long-term world experience in the use of gadoxetic acid (primovist, eovist) for diagnosis of liver diseases confirms its hepatotropic properties. Thus, magnetic resonance imaging (MRI) in hepatobiliary phase of contrast enhancement is valuable for differential diagnosis of focal liver lesions and assessment of liver structure and fibrotic changes. This review is devoted to the most common methods of contrast-enhanced MRI for assessment of liver function and correlation between severity of diffuse structural liver changes and gadoxetic acid accumulation in liver parenchyma. There is no a single method for MRI-based analysis of liver function that is confirmed by active researches in this direction. It was found that liver biopsy can by unnecessary in some cases if contrast-enhanced MRI with gadoxetic acid is available. The advantage of gadoxetic acid is also elimination properties. Indeed, biliary excretion ensures T1-weighted MR-cholangiography for additional assessment of patency, function and anatomy of the bile ducts. However, there are still several questions in this area that necessitates further research.

Coil volume embolization ratio for preventing recanalization after portal vein embolization

PURPOSE

The purpose of this study was to evaluate the optimum volume embolization ratio (VER) for the prevention of recanalization after portal vein embolization (PVE) and the influence of recanalization on future liver remnant (FLR) function using technetium-99m galactosyl human serum albumin single-photon emission computed tomography (99mTc-GSA SPECT/CT) fusion imaging.

METHODS

We analyzed procedural data of 18 patients who underwent PVE from 2015 to 2018. A total of 29 portal branches were embolized (12 anterior branch, 11 posterior branch, 4 left branch, 2 right branch) with absolute ethanol and coils. Portal vein recanalization was evaluated three weeks after PVE by contrast-enhanced CT. We classified the treated portal branches as non-recanalized and recanalized. VER was compared between the groups. In addition, for each patient, we calculated and evaluated the ratio of FLR volume to total liver volume (volumetric %FLR), FLR count to total liver count on 99mTc-GSA SPECT/CT fusion imaging (functional %FLR), and functional-volumetric ratio (functional %FLR/ volumetric %FLR).

RESULTS

Twenty-six portal branches showed no recanalization (non-recanalized group, n=26, 89.7%), while three portal branches showed recanalization (recanalized group, n=3, 10.3%). The median VER was 4.94% (3.12%-11.1%) in the non-recanalized group and 3.49% (2.76%-4.32%) in the recanalized group, which was significantly different between the groups (p = 0.045, Mann-Whitney U test). The median functional-volumetric ratio was 1.16 (1.03-1.50) in non-recanalized patients (n=15, 83.3%) and 1.01 (0.96-1.13) in recanalized patients (n=3, 16.7%), and it was significantly higher in the non-recanalized patients (p = 0.021, Mann-Whitney U test).

CONCLUSION

The VER for preventing recanalization after PVE was approximately 5% (> 4.94%). 99mTc-GSA SPECT/CT fusion imaging revealed a decrease in FLR function due to recanalization after PVE.

A novel model for predicting posthepatectomy liver failure based on liver function and degree of liver resection in patients with hepatocellular carcinoma

BACKGROUND

The permissible liver resection rate for preventing posthepatectomy liver failure (PHLF) remains unclear. We aimed to develop a novel PHLF-predicting model and to strategize hepatectomy for hepatocellular carcinoma (HCC).

METHODS

This retrospective study included 335 HCC patients who underwent anatomical hepatectomy at eight institutions between 2013 and 2017. Risk factors, including volume-associated liver-estimating parameters, for PHLF grade B-C were analyzed in a training set (n = 122) via multivariate analysis, and a PHLF prediction model was developed. The utility of the model was evaluated in a validation set (n = 213).

RESULTS

Our model was based on the three independent risk factors for PHLF identified in the training set: volume-associated indocyanine green retention rate at 15 min, platelet count, and prothrombin time index (the VIPP score). The areas under the receiver operating characteristic curve of the VIPP scores for severe PHLF in the training and validation sets were 0.864 and 0.794, respectively. In both sets, the VIPP score stratified patients at risk for severe PHLF, with a score of 3 (specificity, 0.92) indicating higher risk.

CONCLUSION

Our model facilitates the selection of the appropriate hepatectomy procedure by providing permissible liver resection rates based on VIPP scores.

Post hepatectomy liver failure (PHLF) - Recent advances in prevention and clinical management

BACKGROUND

Posthepatectomy liver failure (PHLF) is a relatively rare but feared complication following liver surgery, and associated with high morbidity, mortality and cost implications. Significant advances have been made in detailed preoperative assessment, particularly of the liver function in an attempt to predict and mitigate this complication.

METHODS

A detailed search of PubMed and Medline was performed using keywords "liver failure", "liver insufficiency", "liver resection", "postoperative", and "post-hepatectomy". Only full texts published in English were considered. Particular emphasis was placed on literature published after 2015. A formal systematic review was not found feasible hence a pragmatic review was performed.

RESULTS

The reported incidence of PHLF varies widely in reported literature due to a historical absence of a universal definition. Incorporation of the now accepted definition and grading of PHLF would suggest the incidence to be between 8 and 12%. Major risk factors include background liver disease, extent of resection and intraoperative course. The vast majority of mortality associated with PHLF is related to sepsis, organ failure and cerebral events. Despite multiple attempts, there has been little progress in the definitive and specific management of liver failure. This review article discusses recent advances made in detailed preoperative evaluation of liver function and evidence-based targeted approach to managing PHLF.

CONCLUSION

PHLF remains a major cause of mortality following liver resection. In absence of a specific remedy, the best approach is mitigating the risk of it happening by detailed assessment of liver function, patient selection and general care of a critically ill patient.

Nuclear imaging methods for the prediction of postoperative morbidity and mortality in patients undergoing localized, liver-directed treatments: a systematic review

Background

Several nuclear imaging methods may predict postoperative liver function and outcome, but none has achieved recommendations in clinical guidelines. The purpose of this systematic review was to summarize the existing knowledge on this topic.

Methods

MEDLINE and Web of Science were searched for studies investigating nuclear medicine imaging methods for the prediction of postoperative liver function in patients undergoing localized, liver-directed treatments. The postoperative endpoints were clinical outcome (morbidity and mortality) as well as measures of postoperative liver function, e.g., liver function assessed by biochemical tests or nuclear imaging.

Results

A total of 1352 references were identified, of which 82 fulfilled the eligibility criteria and were included in the review. Most studies (n = 63) were retrospective studies. The vast majority of studies assessed [^99mTc]Tc-galactosyl serum albumin (GSA) (n = 57) and [^99mTc]Tc-mebrofenin (n = 19). Liver resection was entirely or partly major (involved at least three segments) in 78 reports. There were notable variations in the research methodology, e.g., image acquisition, imaging variables, and endpoints. Thirty-seven studies reported on postoperative mortality, of which most reported descriptive data at the patient level. Of the four reports that performed multivariate analyses, two showed significant predictive results of isotope-based preoperative tests. Fifty-two papers presented data on postoperative liver failure. Multivariate predictive analyses were performed in eighteen trials, of which fifteen showed the significant value of nuclear medicine tests.

Conclusion

There is sparse evidence supporting the significant value of nuclear medicine imaging methods in predicting postoperative mortality. In contrast, a notable number of trials showed a significant prediction of liver failure in multivariate analyses. The research methodology was heterogeneous and exploratory in most trials. Documentation of nuclear medicine tests in this setting awaits the results of properly designed, prospective trials with the standardization of both the nuclear medicine test and endpoints.

The value of 99mTc-labeled galactosyl human serum albumin single-photon emission computerized tomography/computed tomography on regional liver function assessment and posthepatectomy failure prediction in patients with hilar cholangiocarcinoma

BACKGROUND

The aim was to evaluate the value of Tc-labeled galactosyl human serum albumin (Tc-GSA) with single-photon emission computerized tomography (SPECT) in the preoperative assessment of regional liver function and prediction of posthepatectomy liver failure (PHLF) in patients with hilar cholangiocarcinoma (hCCA).

METHODS

Patients with hCCA who underwent Tc-GSA SPECT/computed tomography (CT) before hepatectomy were included. The liver functional parameters of functional liver density (FLD) and predictive residual index (PRI) were calculated based on Tc-GSA SPECT/CT. PHLF was defined according to the International Study Group of Liver Surgery criteria. Univariate and multivariate analyses were used to analyze the risk factors for PHLF. The prediction of PHLF was calculated using receiver operating characteristic curve.

RESULTS

A total of 34 patients were included, 23 of whom underwent preoperative biliary drainage. FLD was significantly higher in patients with drained lobes than that in patients with undrained lobes (0.615 ± 0.190 versus 0.500 ± 0.211, P < 0.05). Sixteen patients suffered PHLF. The ratio of future remnant to total morphological liver volume, future remnant FLD, and PRI differed significantly in patients with and without PHLF according to univariate analysis. PRI was identified as the only independent factor for prediction of PHLF according to multivariate analysis. With a PRI of 0.78, it was possible to predict PHLF with a sensitivity of 83% and a specificity of 93%.

CONCLUSIONS

Tc-GSA SPECT/CT can accurately assess regional liver function and is better able to predict PHLF than conventional methods in patients with hCCA.

Hepatic function assessment to predict post-hepatectomy liver failure: what can we trust? A systematic review

Post hepatectomy liver failure (PHLF) could occur even though an adequate liver volume is preserved. Liver function is not strictly related to the volume and the necessity to pre-operatively predict the future liver remnant (FLR) function is emerging, together with the wide spreading of techniques, aiming to optimize the FLR. The aim of this study was to systematically review all the available tests, to pre-operatively assess the liver function and to estimate the risk of PHLF. A systematic literature research of Medline, Embase, Scopus was performed in accordance to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines, to identify all the studies available for pre-operative liver function tests to assess the risk of PHLF and/or complications. From the 1122 references retrieved, 79 were included in the review. Dynamic functional tests, such as indocyanine green test (ICG), could evaluate only global liver function, with no definition of functional capacity of the remnant. Magnetic resonance imaging (MRI) with liver-specific contrast agents enables both liver function and volume evaluation; the absence of ionizing radiation showed a better patient's compliance. Nuclear imaging studies as hepatobiliary scintigraphy (HBS) present the unique ability to allow a precise evaluation of the segmental liver function of the remnant liver. Liver volume could overestimate liver function. Several liver function tests are available to evaluate the risk of PHLF in the pre-operative setting. However, no single test alone could accurately predict PHLF. Pre-operative combination between a dynamic quantitative test, such as ICG, with MRI or HBS, should enable a more complete functional evaluation. Functional tests to predict PHLF should be chosen according to patient's characteristics, disease, and center experience.

Level of total bilirubin in the bile of the future remnant liver of patients with obstructive jaundice undergoing hepatectomy predicts postoperative liver failure

BACKGROUND

We investigated whether the daily level of total bilirubin in the bile (LTB) excreted from the future remnant liver (FRL) can predict post-hepatectomy liver failure (PHLF) in patients with obstructive jaundice undergoing hepatectomy.

METHODS

Seventy-four patients who underwent biliary drainage and collection of bile juice from the FRL before undergoing right hepatectomy or right/left trisectionectomy with bile duct resection were included. The LTB from the FRL (mg/d) was calculated as the volume of the bile (dL) per day multiplied by the density of total bilirubin in the bile (mg/dL). We compared patients' characteristics with or without PHLF, which was defined as the total serum bilirubin level remaining >10 mg/dL after postoperative day 10. Then, pre- and intraoperative factors related to PHLF were examined.

RESULTS

PHLF was observed in six patients. LTB was significantly lower in the PHLF group. The LTB cut-off value for predicting PHLF, as determined using the receiver operating characteristic curve, was 56 mg/d. On multivariate analysis, LTB was found to be an independent risk factor for PHLF (P = .01, OR 35.88).

CONCLUSIONS

LTB may be a potential functional assessment in jaundiced patients before right hepatectomy and right/left trisectionectomy.

Neoadjuvant chemotherapy followed by curative-intent surgery for perihilar cholangiocarcinoma based on its anatomical resectability classification and lymph node status

BACKGROUND

The prognosis of patients with perihilar cholangiocarcinoma have been unsatisfactory. We established new anatomical resectability classification for patients with localized perihilar cholangiocarcinoma and performed neoadjuvant chemotherapy followed by curative-intent surgery based on its resectability classification and lymph node status to improve prognosis. This study aimed to clarify the long-term outcomes and validation of our strategy.

METHODS

Between September 2010 and August 2018, 72 consecutive patients with perihilar cholangiocarcinoma were classified into three groups: Resectable (R = 29), Borderline resectable (BR = 23), and Locally advanced (LA = 20), based on the two factors of tumor vascular and biliary extension. R with clinically lymph node metastasis, BR, and LA patients received neoadjuvant chemotherapy using gemcitabine plus S-1.

RESULTS

Forty-seven patients (65.3%) received neoadjuvant chemotherapy: R in 8, BR in 21, and 18 in LA, respectively. Fifty-nine patients (68.1%) underwent curative-intent surgery: R in 26, BR in 17, and LA in 6. Five-year disease-specific survival was 31.5% (median survival time: 33.0 months): 50.3% (not reached) in R, 30.0% (31.4 months) in BR, and 16.5% (22.5 months) in LA, which were relatively stratified. Among 49 patients with resection, disease-specific survival was 43.8% (57.0 months): 57.6% (not reached) in R, 41.0% (52.4 months) in BR, and 0% (49.4 months) in LA, which were significantly good prognosis compared to 23 patients without resection (17.2 months). Multivariate analysis identified preoperative high carcinoembryonic antigen levels (more than 8.5 ng/ml) and pT4 as independent poor prognostic factor of patients with resection.

CONCLUSION

Neoadjuvant chemotherapy based on resectability classification and lymph node status was feasible, and was considered efficacious in selected patients.

Survey of preoperative management protocol for perihilar cholangiocarcinoma at 10 Japanese high-volume centers with a combined experience of 2,778 cases

BACKGROUND

In Japan, strategies for preoperative management of perihilar cholangiocarcinoma (PHC) have evolved over the last decade; the operative mortality has significantly reduced to <5%.

METHODS

A questionnaire was sent to 10 institutions based on their case volume. Questionnaire was based on: (1) preoperative biliary drainage, (2) bile replacement, (3) role of synbiotics, (4) remnant liver volume enhancement, (5) predicted remnant liver function, (6) imaging, (7) nutrition, and (8) role of Inchinkoto.

RESULTS

The median case volume was 226 (range 105-889) cases, respectively. Eight institutions preferred endoscopic nasobiliary drainage and two preferred endoscopic biliary stenting for biliary drainage. Nine used bile replacement within 2-3 days of biliary drainage. Four used synbiotics preoperatively. The median cutoff value for future remnant liver volume and serum total bilirubin, at which portal vein embolization (PVE) is done, is <40% and <4 mg/dl. The median interval between PVE and surgery was 3-4 weeks. To predict remnant liver function, indocyanine green retention (n = 8) and clearance rate (n = 2) were mainly used. Five used Inchinkoto to improve liver function. Nine used multidetector computed tomography and direct cholangiography for surgical planning.

CONCLUSION

With appropriate preoperative management of PHC, surgical morbidity and mortality can be reduced. This survey can provide recommendations to improve PHC perioperative outcomes.

Reliability of indocyanine green retention and clearance rates at 15 minutes calculated by dye-dilution cardiac output flowmetry in comparison to blood sampling in patients undergoing hepatic resection

BACKGROUND

The indocyanine green retention rate at 15 min (ICGR15) is a marker of the liver function and is useful for planning hepatectomy. To clarify the ICGR15 and the related clearance value (ICGK) calculated by a dye-dilution cardiac output flowmetry (DCOF), we examined the correlation and clinical significance of the ICGR15 values determined by DCOF and those determined with the conventional blood sampling (BS) procedure.

METHODS

We extracted liver function parameters, including the ICGR15 modified value and ICGK, and the extent of hepatectomy from the clinical and surgical records of 63 patients with various liver diseases in whom the ICGR15 (actual value), R15m (mean), and K (clearance rate per minute) were measured by DCOF.

RESULTS

All the patients were classified as Child-Pugh grade A. Hepatic complications were observed in 10 (16%) patients, but there was no mortality. The mean values of ICGR15 determined by BS (R15-BS) and DCOF (R15-DCOF) were 12.2 ± 8.1% and 11.2 ± 8.7%, respectively. The mean R15m determined by DCOF (R15m-DCOF) was 15.7 ± 10.2%. Significant differences were observed between R15-BS and R15-DCOF (1.1 ± 4.8%; p = 0.002) and R15m-DCOF (4.0 ± 5.9%; p < 0.001). The difference between R15-BS and R15m-DCOF was greater than that between R15-BS and R15-DCOF. Correlation between R15-BS and R15-DCOF was significant r = 0.839 (p < 0.001).

CONCLUSIONS

The ICGR15 measured by DCOF shows comparable reliability and stability to the BS method, which is useful for planning hepatectomy.

Accuracy of estimated total liver volume formulas before liver resection

BACKGROUND

Future remnant liver volume is used to predict the risk for liver failure in patients who will undergo major liver resection. Formulas to estimate total liver volume based on biometric data are widely used to calculate future remnant liver volume; however, it remains unclear which formula is most accurate. This study evaluated published estimate total liver volume formulas to determine which formula best predicts the actual future remnant liver volume based on measurements in a large number of patients who underwent associating liver partition and portal vein ligation for staged hepatectomy surgery.

METHODS

All patients with complete liver volume data in the associating liver partition and portal vein ligation for staged hepatectomy registry were included in this study. Estimate total liver volume and estimated future remnant liver volume were calculated for 16 published formulas. The median over- or underestimation compared with actual measured volumes were determined for estimate total liver volume and future remnant liver volume. The proportion of patients with an under- or overestimated future remnant liver volume for each formula were compared with each other using a 25% cut-off for each formula.

RESULTS

Among 529 studied patients, the formulas ranged from a 19% underestimation to a 63% overestimation of estimate total liver volume. Estimation of future remnant liver volume lead to a 10% underestimation to a 5% overestimation among the formulas. Of all studied formulas, the Vauthey1 formula was the most accurate, generating underestimation of future remnant liver volume in 20% and overestimation of future remnant liver volume in 6% of patients.

CONCLUSION

Validation of 16 published total liver volume formulas in a multicenter international cohort of 529 patients that underwent staged hepatectomy revealed that the Vauthey formula (estimate total liver volume = 18.51 × body weight + 191.8) provides the most accurate prediction of the actual future remnant liver volume.

99mTc-GSA SPECT/CT fusion imaging for hepatectomy candidates with extremely deteriorated ICG value

PURPOSE

The value of indocyanine green (ICG) test is negatively affected in patients with intrahepatic shunt, ICG excretory defect, or jaundice. This study evaluated ^99mTc-GSA SPECT/CT fusion imaging for assessing liver function in patients with severely deteriorated ICG values.

MATERIALS AND METHODS

Thirteen hepatectomy candidates with ICG retention rates over 40% were retrospectively analyzed. The ICG clearance rate (KICG) and estimated KICG obtained by ^99mTc-GSA scintigraphy (KGSA) were used to evaluate preoperative whole liver function. Remnant liver function was assessed using the remnant (rem) KICG (= KICG × volumetric rate) and remKGSA (= KGSA × functional rate) indices; hepatectomy was considered unsafe for values < 0.05. The correlations of remKICG and remKGSA with postoperative mortality and morbidity were also investigated.

RESULTS

KGSA values were significantly greater than KICG values (median: 0.12 vs. 0.059; p < 0.01); remKGSA values were greater than remKICG values in all patients (median: 0.107 vs. 0.0413; p < 0.01). Hepatectomy was considered unsafe in 70% patients using remKICG, and in none of those using remKGSA; liver failure or postoperative mortality did not occur.

CONCLUSIONS

^99mTc-GSA SPECT/CT fusion imaging enables more accurate liver function assessment than the ICG test in patients with severely deteriorated ICG values.

Predicting hepatic failure with a new diagnostic technique by preoperative liver scintigraphy and computed tomography: a pilot study in 123 patients undergoing liver resection

Background

A novel index, total liver LU15, has been identified as a surrogate marker for liver function. We evaluated the ability of preoperative remnant liver LU15 values to predict postoperative hepatic failure.

Methods

Preoperative risk factors for postoperative hepatic failure and remnant liver LU15 were evaluated in 123 patients undergoing liver resection for several diseases from September 1st, 2007 to December 1st, 2016. We calculated the remnant liver LU15 value from the total liver LU15 value and the functional remnant liver ratio. Risk factors for postoperative hepatic failure was determined by univariate and multivariate analysis.

Results

Hepatic failure grade B/C developed postoperatively in six patients of seven patients within Makuuchi criteria / without criteria for remnant liver LU15. Operative time (p = 0.0242) and criteria for remnant liver LU15 (p = 0.0001) were prognostic factors for hepatic failure according to the univariate analysis. And criteria for remnant liver LU15 (p = 0.0009) was only prognostic factor by multivariate analysis.

Conclusion

Based on the findings form this pilot study, it appears that patients with a remnant liver LU15 value of 13 or less may have a high risk of postoperative hepatic failure.

ICG Clearance Test and 99mTc-GSA SPECT/CT Fusion Images

Preoperative estimation of future remnant liver function is critical for major hepatic surgery to avoid postoperative morbidity and mortality. Among several liver function tests, the indocyanine green (ICG) clearance test is still the most popular dynamic method. The usefulness of ICG clearance test parameters, such as ICGR15, KICG, or PDRICG, has been reported by many investigators. The transcutaneous non-invasive pulse dye densitometry system has made the ICG clearance test more convenient and attractive, even in Western countries. The concept of future remnant KICG (rem KICG), which combines the functional aspect and the volumetric factor of the future remnant liver, seems ideal for determining the maximum extent of major hepatic resection that will not cause postoperative liver failure. For damaged livers with functional heterogeneity among the hepatic segments, fusion images combining technetium-99m-diethylenetriaminepentaacetic acid-galactosyl human serum albumin single photon emission computed tomography (99mTc-GSA SPECT) and X-ray CT are helpful to precisely estimate the functional reserve of the future remnant liver. Another technique for image-based liver function estimation, gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid(Gd-EOB)-enhanced magnetic resonance imaging, may be an ideal candidate for the preoperative determination of future remnant liver function. Using these methods effectively, morbidity and mortality after major hepatic resection could be reduced.

A novel utility of 99mTc-GSA SPECT/CT fusion imaging: detection of inadequate portal vein embolization

PURPOSE

Our aim was to determine the utility of Tc-99m-diethylenetriaminepentaacetic acid-galactosyl human serum albumin single-photon-emission computed tomography (^99mTc-GSA SPECT/CT) fusion imaging for detecting incomplete portal vein embolization (PVE).

MATERIALS AND METHODS

Fifty-five candidates underwent PVE. Among them, five underwent second PVE. Detectability of first inadequate PVE using CT and ^99mTc-GSA SPECT/CT fusion imaging was analyzed.

RESULTS

Cases of inadequate PVE were detected in three patients using CT and in five using ^99mTc-GSA SPECT/CT fusion imaging. Fusion imaging detected two cases of insufficient PVE in which portal branches were apparently well embolized on CT. Median value for volumetric rate in the embolized liver was 63.3% after the first PVE and 54.7% after the second (P < 0.01). Median functional rate value in embolized liver was 60.1% after the first PVE and 49.4% after the second (P < 0.01). Median value for change of volumetric and functional rates in embolized liver after the second PVE was 7.1 and 10.3%, respectively, and change of functional rate was greater than that of volumetric rate (P < 0.01).

CONCLUSIONS

^99mTc-GSA SPECT/CT fusion imaging was useful for detecting inadequate PVE, and second PVE was effective for increasing volumetric and functional rates.

Predictability of 99mTc-Galactosyl Human Serum Albumin Scintigraphy for Posthepatectomy Liver Failure

OBJECTIVE

Posthepatectomy liver failure (PHLF) is one of the most serious complications after hepatectomy. The objective of the present study is to assess the potential diagnostic ability of ^99mTc-galactosyl human serum albumin (GSA) scintigraphy to predict PHLF as defined by the International Study Group of Liver Surgery (ISGLS).

MATERIALS AND METHODS

Data from 100 patients who underwent ^99mTc-GSA scintigraphy and subsequent hepatectomy were retrospectively analyzed. The blood clearance ratio (HH15), hepatic uptake ratio (LHL15), and maximal removal rate (Rmax) of ^99mTc-GSA (GSA-Rmax) were calculated as scintigraphic parameters for the total liver. In addition to the ratio of preoperatively estimated remnant liver (ERL) counts to total liver counts (rERL-GSA), the ratio of actual remnant liver (ARL) counts to total liver counts (rARL-GSA), determined by applying a more accurate resection line with reference to both pre- and postoperative CT, was obtained from SPECT images. Functional remnant liver parameters of ERL-LHL15 (LHL15 of the estimated remnant liver), ERL-Rmax (maximal removal rate of estimated remnant liver counts), ARL-LHL15 (LHL15 of the actual remnant liver), and ARL-Rmax (maximal removal rate of actual remnant liver counts) were calculated using these values. ROC analysis was performed to evaluate the ability of these parameters to predict PHLF. Multivariate analysis was performed to identify independent predictors of PHLF.

RESULTS

PHLF occurred in 33 patients. Each of the ARL parameters had a significantly higher diagnostic performance compared with the corresponding ERL parameter (AUC values: for rARL-GSA vs rERL-GSA, 0.77 vs 0.62 [p = 0.0004]; for ARL-LHL15 vs ERL-LHL15, 0.79 vs 0.64 [p = 0.0005]; and for ARL-Rmax vs ERL-Rmax, 0.78 vs 0.66 [p = 0.0003]). According to multivariate analysis, each of three ARL parameters was identified as an independent predictor of PHLF (p < 0.0001 for all).

CONCLUSION

Technetium-99m-labeled GSA scintigraphy is useful for predicting PHLF, particularly for applying an accurate resection line on GSA-SPECT images.

Liver Function Assessment Using Technetium 99m-Galactosyl Single-Photon Emission Computed Tomography/CT Fusion Imaging: A Prospective Trial

BACKGROUND

The prediction of postoperative liver function remains a largely subjective practice based on CT volumetric analysis. However, future liver volume after a hepatectomy is not the only factor that contributes to postoperative liver function and outcomes.

STUDY DESIGN

In this prospective trial, 185 consecutive patients who underwent liver operations between 2014 and 2015 were studied. Volumetric and functional rates of remnant liver were measured using technetium 99m-galactosyl human serum albumin single-photon emission computed tomography/CT fusion imaging to evaluate post-hepatectomy remnant liver function. Remnant indocyanine green clearance rate using galactosyl (KGSA) (KGSA × functional rate) was used to predict future remnant liver function. Hepatectomy was considered safe for patients with remnant KGSA values ≥0.05, and the primary end point was to determine the accuracy and reliability of this criteria. The prediction of the 90-day major complication and mortality rates was assessed.

RESULTS

Median hospital stay was 9 days and median ICU stay was 1 day, with only 1 in-hospital death (90-day mortality rate 0.5%). Overall morbidity rate evaluated according to the Clavien-Dindo classification was 9%. For post-hepatectomy liver failure definitions, the International Study Group of Liver Surgery definition was fulfilled in 14 patients (8%), with the majority being grade B (50%), compared with 2 patients (1%) fulfilling the "50-50" criteria, and 0 patients (0%) fulfilling the _PeakBili >7 criteria.

CONCLUSIONS

Results of this study showed that remnant KGSA provided information that allowed us to predict remnant liver function. This information will be important for surgeons when deciding on a treatment plan for patients with liver diseases. (ClinicalTrials.gov ID: NCT02013895).