Liver functional volumetry for portal vein embolization using a newly developed 99mTc-galactosyl human serum albumin scintigraphy SPECT-computed tomography fusion system

Management of potential portal vein thrombus during laparoscopic right hemihepatectomy following portal vein embolization

BACKGROUND

Portal vein embolization (PVE) is often performed prior to right hemihepatectomy (RH) to increase the future liver remnants. However, intraoperative removal of portal vein thrombus (PVT) is occasionally required. An algorithm for treating the right branch of the PV using laparoscopic RH (LRH) after PVE is lacking and requires further investigation.

METHODS

In our department, after the confirmation of a lack of extension of PVT to the main portal trunk or left branch on preoperative examination (ultrasound and contrast-enhanced computed tomography), a final evaluation was performed using intraoperative ultrasonography (IOUS). Here we present the cases of eight patients who underwent LRH after PVE and examine the safety of our treatment strategies.

RESULTS

IOUS revealed PVT extension into the main portal trunk in two cases. For the other six patients without PVT extension, we continued the laparoscopic procedure. In contrast, in the two cases with PVT extension, we converted to laparotomy after hepatic transection and removed the PVT. The median operation time for hepatectomy was 562 min (421-659 min), the median blood loss was 293 mL (85-1010 mL), no liver-related postoperative complications were observed, and the median length of stay was 10 days (6-34 days).

CONCLUSIONS

PVT evaluation and removal are important in cases of LRH after PVE. Our strategy is safe and IOUS is particularly useful for laparoscopically evaluating PVT extension.

A Novel Method Using Gadolinium-Ethoxybenzyl Diethylenetriamine Pentaacetate Acid-Enhanced Magnetic Resonance Imaging for Predicting Post-Hepatectomy Liver Failure in Hepatocellular Carcinoma Patients with a Major Portal Vein Tumor Thrombus

INTRODUCTION

The usefulness of gadolinium-ethoxybenzyl diethylenetriamine pentaacetate acid-enhanced magnetic resonance imaging (EOB-MRI) in assessing the functional future remnant liver volume (fFRLV) to predict post-hepatectomy liver failure (PHLF) has been previously reported. Herein, we evaluated the efficacy of this technique in patients with hepatocellular carcinoma (HCC) with a major portal vein tumor thrombus (PVTT).

METHODS

This study included 21 patients with PVTT in the ipsilateral first-order branch (Vp3) and 30 patients with PVTT in the main trunk/contralateral branch (Vp4). To evaluate fFRLV, the signal intensity (SI) of the remnant liver was determined on T1-weighted images, using both conventional and newly developed methods. The fFRLV was calculated using the SI of the remnant liver and muscle, remnant liver volume, and body surface area. Preoperative factors predicting PHLF (≥grade B) in HCC patients with Vp3/4 PVTT were evaluated.

RESULTS

In the Vp3 group, we found fFRLV area under the receiver-operating characteristic curves (AUCs) above 0.70 (AUC = 0.875, 0.750) using EOB-MRI results calculated using either the plot or whole method. None of the parameters in the Vp4 group had an AUC greater than 0.70.

CONCLUSION

The fFRLV calculated by EOB-MRI using the whole method can be as useful as the conventional method in predicting PHLF (≥grade B) for HCC patients with Vp3 PVTT.

Current status of preoperative risk assessment for posthepatectomy liver failure in patients with hepatocellular carcinoma

Liver resection is an effective therapeutic option for patients with hepatocellular carcinoma. However, posthepatectomy liver failure (PHLF) remains a major cause of hepatectomy-related mortality, and the accurate prediction of PHLF based on preoperative assessment of liver functional reserve is a critical issue. The definition of PHLF proposed by the International Study Group for Liver Surgery has gained acceptance as a standard grading criterion. Liver function can be estimated using a variety of parameters, including routine blood biochemical examinations, clinical scoring systems, dynamic liver function tests, liver stiffness and fibrosis markers, and imaging studies. The Child-Pugh score and model for end-stage liver disease scores are conventionally used for estimating liver decompensation, although the alternatively developed albumin-bilirubin score shows superior performance for predicting hepatic dysfunction. Indocyanine green clearance, a dynamic liver function test mostly used in Japan and other Asian countries, serves as a quantitative estimation of liver function reserve and helps determine indications for surgical procedures according to the estimated risk of PHLF. In an attempt to improve predictive accuracy, specific evaluation of liver fibrosis and portal hypertension has gained popularity, including liver stiffness measurements using ultrasonography or magnetic resonance elastography, as well as noninvasive fibrosis markers. Imaging modalities, including Tc-99m-labeled galactosyl serum albumin scintigraphy and gadolinium-enhanced magnetic resonance imaging, are used for preoperative evaluation in combination with liver volume. This review aims to provide an overview of the usefulness of current options for the preoperative assessment of liver function in predicting PHLF.

Nonsuperiority of technetium-99m-galactosyl human serum albumin scintigraphy over conventional volumetry for assessing the future liver remnant in patients undergoing hepatectomy after portal vein embolization

BACKGROUND

Technetium-99m-galactosyl human serum albumin scintigraphy is preferred for assessing the liver functional reserve in patients undergoing hepatectomy, but its superiority over computed tomography volumetry after portal vein embolization and subsequent hepatectomy remains elusive. We aimed to compare technetium-99m-galactosyl human serum albumin scintigraphy with conventional computed tomography volumetry for predicting posthepatectomy liver failure in patients after portal vein embolization.

METHODS

This retrospective study analyzed 152 consecutive patients who underwent hepatobiliary cancer resection after portal vein embolization between 2006 and 2021. Posthepatectomy liver failure was graded according to the International Study Group of Liver Surgery criteria. The predictive abilities for posthepatectomy liver failure were compared between the future remnant uptake (%) by technetium-99m-galactosyl human serum albumin scintigraphy and the future remnant volume (%) by computed tomography volumetry.

RESULTS

Future remnant uptake (%) was significantly greater than future remnant volume (%) after portal vein embolization (47.9% vs 40.8%; P < .001), while the values were comparable before portal vein embolization (32.7% vs 31.2%; P = .116). Receiver operating characteristic curve analysis revealed that post-portal vein embolization future remnant volume (%) had a significantly higher area under the curve than post-portal vein embolization future remnant uptake (%) (0.709 vs 0.630; P = .046) for predicting posthepatectomy liver failure. Multivariable analysis revealed that post-portal vein embolization future remnant volume (%) independently predicted posthepatectomy liver failure, but future remnant uptake (%) did not. Although the incidence of posthepatectomy liver failure grade ≥B was 17.8% when indocyanine green-clearance of the future liver remnant based on both future remnant volume (%) and future remnant uptake (%) was ≥0.05, it was higher in other combinations: 55.6% for indocyanine green clearance of the remnant volume ≥0.05/indocyanine green clearance of the remnant uptake ≤0.05; 50.0% for indocyanine green clearance of the remnant volume ≤0.05/indocyanine green clearance of the remnant uptake ≥0.05; and 50% for indocyanine green clearance of the remnant volume ≤0.05/indocyanine green clearance of the remnant uptake ≤0.05.

CONCLUSIONS

Technetium-99m-galactosyl human serum albumin scintigraphy is not superior to computed tomography volumetry for assessing the future liver remnant in patients undergoing major hepatectomy after portal vein embolization.

Impairment of perioperative activities of daily living is associated with poor prognosis following hepatectomy for hepatocellular carcinoma

BACKGROUND

The number of cancer patients with impairment of activities of daily living (ADLs) has increased. This study aimed to examine associations of perioperative Barthel index score, a validated measure of ADLs, with survival outcomes following hepatectomy for hepatocellular carcinoma (HCC).

METHODS

We analyzed data of 492 consecutive patients who underwent hepatectomy for HCC between 2010 and 2018. Pre- and postoperative ADLs were assessed using the Barthel index (range, 0-100; higher scores indicate greater independence). Preoperative Barthel index score ≤85 or postoperative Barthel index score ≤85 was defined as impairment of perioperative ADLs. Cox proportional hazards regression was used to calculate hazard ratios (HRs) after adjusting for potential confounders.

RESULTS

Among the 492 patients, 26 (5.2%) had a preoperative Barthel index score ≤85 and 95 (19%) had a postoperative Barthel index score ≤85. Impairment of perioperative ADLs was independently associated with shorter overall survival (multivariable HR: 1.75, 95% confidence interval [CI]: 1.06-2.81, p = 0.028). The association of impairment of perioperative ADLs with recurrence-free survival was not statistically significant.

CONCLUSION

Impairment of perioperative ADLs is associated with poor prognosis following hepatectomy for HCC. Maintenance and improvement of perioperative ADLs would be important to provide favorable long-term outcomes in patients with HCC.

Portal vein embolization via the ipsilateral percutaneous transhepatic approach versus laparotomic transileocecal approach: complications, profile and changes in future liver remnant volume

OBJECTIVE

Major liver resection is an effective treatment option for patients with liver malignancy. The future liver remnant (FLR) volume and complications after portal vein embolization (PVE) were compared between the ipsilateral right portal vein (PTPE) and transileocolic (TIPE) approaches.

METHODS

A total of 42 patients (TIPE, n = 22; PTPE, n = 20) underwent right lobectomy after PVE. CT and hepatobiliary scintigraphy were repeated before and after PVE. The blood examination findings and the FLR values (FLRCT: calculated from CT, %FLRCT: FLRCT ratio, %FLRSPECT: FLR ratio using single photon emission CT, FLRCT/BS: FLRCT to body surface ratio) were compared between two approach sites. The complications and mortality were also analyzed after PVE and major right hepatectomy.

RESULTS

There were no significant differences in the patient characteristics, blood examination findings or FLR values between two groups. Adequate liver regeneration was observed without significant differences between PTPE and TIPE (increased ratio of FLRCT: 8.7% vs 19.2%, p = 0.15 [25-75 percentile: 17.1-60.4], %FLRCT: 11.2% vs 8.3%, p = 0.25 [6.3-13.3], %FLRSPECT: 15.4% vs 19.2%, p = 0.09 [16.0-22.4], FLRCT/BS: 33.6% vs 47.1%, p = 0.19 [17.2-60.4], respectively), but TIPE required a significantly longer procedure time than PTPE [181.4 min vs 108.7 min, p < 0.01 (103.3-193.5)]. However, one patient was converted to TIPE due to bleeding during PTPE. After right lobectomy, portal vein stenosis or thrombosis was noted in three patients [two with TIPE (9.1%) and one with PTPE (5%)] and three TIPE patients died within 90 days (13.6%) after right hepatectomy.

CONCLUSION

FLR volume significantly increased after PVE, regardless of the approach sites; however, PTPE is a useful technique with a shorter procedure time.

Prediction with functional liver volume assessment to achieve the resection limit after portal vein embolization in patients scheduled major hepatectomy

BACKGROUND

Preoperative portal vein embolization (PVE) stimulates liver hypertrophy and improves the safety of major hepatectomy. It is essential to predict the future remnant liver volume (FRLV) and resection limit following PVE. Previously, we reported that evaluating functional FRLV (fFRLV) using EOB-MRI could predict post-hepatectomy liver failure. In this study, we investigated the usefulness of fFRLV in predicting the achieving of adequate resection limit for safe hepatectomy following PVE.

METHODS

We included 55 patients who underwent PVE and were scheduled for major hepatectomy. We calculated the liver-to-muscle ratio in the remnant liver and fFRLV using EOB-MRI. We investigated the pre-PVE variables in determining the nonachievement of the resection limit.

RESULTS

The median observation period between PVE and the first evaluation was 21 days, and the median growth rate of FRLV was 26.4%. In 54.5% of patients, the resection limit of fFRLV (615 mL/m²) was achieved. In logistic regression and receiver-operating characteristic analyses, pre-PVE fFRLV (p < 0.001, area under the curve: 0.852) was the reliable predictor of achieving the resection limit; the cutoff value of pre-PVE fFRLV was 446 mL/m².

CONCLUSION

Pre-PVE fFRLV can be useful in predicting the achievement of adequate resection limit following PVE.

Right hepatectomy with preservation of the entire caudate lobe in patients with metastatic liver tumors: a case of a new hepatectomy technique and treatment strategy for patients with marginal liver function

Background

Performing major hepatectomy for patients with marginal hepatic function is challenging. In some cases, the procedure is contraindicated owing to the threat of postoperative liver failure. In this case report, we present the first case of marginal liver function (indocyanine green clearance retention rate at 15 min [ICGR15]: 28%) successfully treated with right hepatectomy, resulting in total caudate lobe preservation.

Case presentation

A 71-year-old man was diagnosed with sigmoid colon cancer with three liver metastases (S5, S7, and S8). All of metastatic lesions shrunk after chemotherapy, but his ICGR15 and indocyanine green clearance rate (ICGK) were 21% and 0.12, respectively. Moreover, the remnant liver volume was only 39%. Therefore, portal venous embolism (PVE) of the right portal vein was suggested. Portography showed divergence of the considerably preserved right caudate lobe branch (PV1R) from the root of the right portal vein. The liver function was reevaluated 18 days after PVE was suggested. During this time, the ICGR15 (21–28%) and ICGK rate (0.12–0.10) deteriorated. The right caudate lobe was significantly enlarged; thus, a total caudate lobe-preserving hepatectomy (TCPRx) was performed. Patients eligible for TCPRx included those with (1) hepatocellular carcinoma or metastatic liver cancer, (2) no tumor in the caudate lobe, (3) marginal liver function (ICG Krem greater than 0.05 if TCPRx was adapted; otherwise, less than 0.05) and Child–Pugh classification category A, and (4) preserved PV1R and right caudate bile duct branch. The procedure was performed through (A) precise estimation of the remnant liver volume preoperatively, (B) repeated intraoperative cholangiography to confirm the biliary branch of the right caudate lobe (B1R) conservation, and (C) stapler division of posterior and anterior Glisson’s pedicles laterally to avoid injuries to the PV1R and B1R.

Conclusions

Right hepatectomy with total caudate lobe preservation, following PVE, was a safe and viable surgical technique for patients with marginal liver function.

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.

Volumetric assessment and clinical predictors of cirrhosis in patients undergoing hepatectomy for hepatocellular carcinoma with presumed normal liver function

AIM

Indocyanine green retention rate at 15 min (ICGR15) is a frequently used indicator of liver function. Herein, clinicopathological characteristics of cirrhotic patients with normal ICGR15 value (< 10%) were investigated, as these patients have risk of postoperative liver insufficiency when receiving a major hepatic resection.

METHODS

Patients undergoing hepatectomy for hepatocellular carcinoma were divided into three groups: non-cirrhotic livers (Group A, n = 112): cirrhotic livers with ICGR15 < 10% (Group B, n = 71): and cirrhotic livers with ICGR15 > 10% (Group C, n = 296). Background characteristics and surgical outcomes were compared between groups. Functional liver volume (FLV) was computed using total liver volume and signal intensity ratio. Liver parenchymal cell volume ratio was measured in non-cancerous tissue obtained from resected specimens. Univariate and multivariate analyses were performed to detect clinical characteristics correlating with cirrhotic liver pathology with normal ICGR15.

RESULTS

There was no significant difference between groups in TLV. FLV was gradually reduced from Group A toward Group C. Liver parenchymal cell volume ratio was also gradually reduced from Group A toward Group C. Multivariate analysis revealed that platelet count (< 12 × 10⁴/mm³) (p = 0.001) and prothrombin time (< 80%) (p = 0.025) were significantly associated with cirrhotic liver pathology among patients with normal ICGR15.

CONCLUSION

Our results suggested that cirrhotic liver pathology despite normal liver function was characterized by slightly decreasing liver parenchyma as well as slight degree of fibrosis. Platelet count and PT% are useful for predicting liver cirrhosis with normal ICGR15.

Differences in the safety line of the future liver remnant plasma clearance rate of indocyanine green necessary to prevent post-hepatectomy liver failure associated with underlying diseases

PURPOSE

To evaluate differences in the safety line of the future liver remnant plasma clearance rate of indocyanine green (RemK) necessary to prevent posthepatectomy liver failure (PHLF) associated with liver tumors and comorbidities.

METHODS

The subjects of this retrospective study were patients who underwent trisectionectomy, hemihepatectomy, or sectionectomy, other than left lateral sectionectomy, between 2011 and 2018, at the Shizuoka Cancer Center. We analyzed the risk factors for PHLF grades B and C and then evaluated the RemK in these groups, according to various risk factors.

RESULTS

A total of 463 patients were selected for the analyses. Among the patients with PHLF grades B and C, those with diabetes mellitus (DM), liver cirrhosis (LC), or hepatocellular carcinoma (HCC) had significantly higher RemK than those without these diseases. Multivariate analysis identified RemK ≤ 0.078, DM, and creatinine clearance rate < 60 mL/min as independent risk factors for PHLF grades B and C.

CONCLUSIONS

Hepatectomy for patients with DM, HCC, or LC requires more functional hepatic reserve than that evaluated by RemK.

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.

Oncological benefits of portal vein embolization for patients with hepatocellular carcinoma

Portal vein embolization (PVE) for hepatocellular carcinoma (HCC) was first introduced in 1986 and has been continuously developed throughout the years. Basically, PVE has been applied to expand the indication of liver resection for HCC patients of insufficient future liver remnant. Importantly, PVE can result in tumor progression in both embolized and non-embolized livers; however, long-term survival after liver resection following PVE is at least not inferior compared with liver resection alone despite the smaller future liver remnant volume. Five-year disease-free survival and 5-year overall survival were 17% to 49% and 12% to 53% in non-PVE patients, and 21% to 78% and 44% to 72% in PVE patients, respectively. At present, it has proven that PVE has multiple oncological advantages for both surgical and nonsurgical treatments. PVE can also enhance the anticancer effects of transarterial chemoembolization and can avoid intraportal tumor cell dissemination. Additional interventional transarterial chemoembolization and hepatic vein embolization as well as surgical two-stage hepatectomy and associated liver partition and portal vein ligation for staged hepatectomy can enhance the oncological benefit of PVE monotherapy. Taken together, PVE is an important treatment which we recommend for listing in the guidelines for HCC treatment strategies.

Functional transition: Inconsistently parallel to the increase in future liver remnant volume after preoperative portal vein embolization

BACKGROUND

Preoperative portal vein embolization (PVE) is a widely used strategy to enable major hepatectomy in patients with insufficient liver remnant. PVE induces hypertrophy of the future liver remnant (FLR) and a shift of the functional reserve to the FLR. However, whether the increase of the FLR volume (FLRV) corresponds to the functional transition after PVE remains unclear.

AIM

To investigate the sequential relationship between the increase in FLRV and functional transition after preoperative PVE using 3-dimensional (3D) computed tomography (CT) and ^99mTc-galactosyl-human serum albumin (^99mTc-GSA) single-photon emission computed tomography (SPECT) fusion images.

METHODS

Thirty-three patients who underwent major hepatectomy following PVE at the Department of Gastroenterological Surgery I, Hokkaido University Hospital between October 2013 and March 2018 were enrolled. Three-phase dynamic multidetector CT and ^99mTc-GSA SPECT scintigraphy were performed at pre-PVE, and at 1 and 2 wk after PVE; 3D ^99mTc-GSA SPECT CT-fused images were constructed from the Digital Imaging and Communications in Medicine data using 3D image analysis system. Functional FLRV (FFLRV) was defined as the total liver volume × (FLR volume counts/total liver volume counts) on the 3D ^99mTc-GSA SPECT CT-fused images. The calculated FFLRV was compared with FLRV.

RESULTS

FFLRV increased by a significantly larger extent than FLRV at 1 and 2 wk after PVE (P < 0.01). The increase in FFLRV and FLRV was 55.1% ± 41.6% and 26.7% ± 17.8% (P < 0.001), respectively, at 1 wk after PVE, and 64.2% ± 33.3% and 36.8% ± 18.9% (P < 0.001), respectively, at 2 wk after PVE. In 3 of the 33 patients, FFLRV levels decreased below FLRV at 2 wk. One of the three patients showed rapidly progressive fatty changes in FLR. The biopsy at 4 wk after PVE showed macro- and micro-vesicular steatosis of more than 40%, which improved to 10%. Radical resection was performed at 13 wk after PVE. The patient recovered uneventfully without any symptoms of pos-toperative liver failure.

CONCLUSION

The functional transition lagged behind the increase in FLRV after PVE in some cases. Evaluating both volume and function is needed to determine the optimal timing of hepatectomy after PVE.

Prognostic value of future liver remnant LU15 index of 99mTc-galactosyl serum albumin scintigraphy for predicting posthepatectomy liver failure

There is no gold standard indicator that is currently used to predict posthepatectomy liver failure (PHLF). A novel indicator of liver function, the LU15 index of ^99mTc-galactosyl serum albumin (GSA) scintigraphy, refers to the liver uptake ratio over a 15-min interval. We aimed to evaluate the usefulness of the future liver remnant (FLR)-LU15 in predicting PHLF. The clinical data of 102 patients (70 males and 32 females; median age, 70 years) who underwent liver resection between January 2011 and August 2019 were analyzed. The FLR-LU15 was calculated by a fusion of simulated 3-dimensional images and ^99mTc-GSA scintigraphy. PHLF was determined according to the definition of the International Study Group of Liver Surgery. The FLR-LU15 was an independent risk factor for PHLF ≥ Grade B according to multivariate analysis, and its value correlated with the PHLF grade. The area under the receiver operating characteristic curve of the FLR-LU15 for PHLF ≥ Grade B was 0.816 (95% confidence interval, 0.704–0.929), which was better than that of other indicators. When the cut-off value of FLR-LU15 was set at 16.7, the sensitivity was 86.7%, specificity was 74.7%, and odds ratio was 19.2 (95% confidence interval, 4.0–90.9), all of which were superior to other indicators. If the cut-off value was 13, the positive predictive value was 57.1%. The FLR-LU15 is a useful predictor of PHLF and may be more reliable than other predictors.

Evaluation of Liver Function and the Role of Biliary Drainage before Major Hepatic Resections

Background

Prevention of posthepatectomy liver failure is a prerequisite for improving the postoperative outcome of perihilar cholangiocarcinoma. From this perspective, appropriate assessment of future liver remnant (FLR) function and the optimized preparation are mandatory.

Summary

FLR volume ratio using CT volumetry based on 3-dimensional vascular imaging is the current assessment yardstick and is sufficient for assessing a normal liver. However, in a liver with underling parenchymal disease such as fibrosis or prolonged jaundice, weighing up the degree of liver damage against the FLR volume ratio is necessary to know the real FLR function. For this purpose, the indocyanine green (ICG) clearance test, monoethylglycinexylidide (MEGX) test, liver maximum capacity (LiMAX) test, ^99mTc-labeled galactosyl human serum albumin (^99mTc-GSA) scintigraphy, albumin-bilirubin (ALBI) grade, and ALPlat (albumin × platelets) criterion are used. After the optimization of FLR function by means of portal vein embolization or associating liver partition and PVL (portal vein ligation) for staged hepatectomy (ALPPS), SPECT scintigraphy with either ^99mTc-GSA or ^99mTc-mebrofenin compensates for misestimation due to the regional heterogeneity of liver function. The role of preoperative biliary drainage has long been debated, with the associated complications having led to a lack of approval. However, the recent establishment of safety and an improvement in success rates of endoscopic biliary drainage seem to be changing the awareness of the importance of biliary drainage.

Key Messages

Appropriate selection of an assessment method is of prime importance to predict the FLR function according to the preoperative condition of the liver. Preoperative biliary drainage in patients with perihilar cholangiocarcinoma is gaining support due to the increasing safety and success rate, especially in patients who need optimization of their liver function before hepatectomy.

Hybrid transileocecal portal vein embolization associated with staging laparoscopy for planned major hepatectomy in advanced hepatobiliary cancers

BACKGROUND

Portal vein embolization (PVE) is widely used to promote the hypertrophy of a future liver remnant (FLR) and reduce posthepatectomy liver failure. The aim of this study was to evaluate the efficacy of transileocecal portal embolization (TIPE) associated with staging laparoscopy (hybrid lap-TIPE) for a planned hepatectomy in advanced hepatobiliary cancers.

METHODS

The hybrid lap-TIPE procedure consisted of staging laparoscopy for complete screening of the abdominal cavity with cytoreductive surgery and subsequent TIPE. Data on hybrid lap-TIPE, performed between March 2013 and February 2020, were collected retrospectively.

RESULTS

Hybrid lap-TIPE was conducted for 52 patients, and a subsequent TIPE was accomplished in 42 patients (80.8%), since staging laparoscopy detected latent or unresectable factors in 13 patients (25.0%), among which 2 patients with hepatocellular carcinoma and 1 with colorectal liver metastasis received laparoscopic cytoreductive surgery for latent lesions in the FLR. Finally, radical hepatectomy was completed in 36 patients (69.2%), including 3 patients who underwent cytoreductive surgery. The most common operation was an extended right hepatectomy (50.0%), followed by right hepatectomy (30.6%), including 3 hepatopancreatoduodenectomies. The overall morbidity associated with hybrid lap-TIPE and hepatectomy was 7.1% and 41.7%, respectively. The mortality associated with hybrid lap-TIPE and hepatectomy was 0% and 5.6%, respectively. The rates of 2-year survival and 2-year disease-free survival were 64.8% and 61.9%, respectively, after hepatectomy.

CONCLUSIONS

Hybrid lap-TIPE is safe and could be a useful treatment option for patients with advanced hepatobiliary cancer because it can help to identify optimal candidates for PVE followed by a planned hepatectomy.

Stereotactic Body Radiotherapy Based on 99mTc-GSA SPECT Image-guided Inverse Planning for Hepatocellular Carcinoma

BACKGROUND/AIM

A recent planning study suggested that ^99mTc-labelled diethylene triamine pentaacetate-galactosyl human serum albumin (^99mTc-GSA) single-photon emission computed tomography (SPECT) image-guided inverse planning (IGIP) shows dosimetric superiority to conventional planning in sparing liver function. Here, we report the first clinical translation of ^99mTc-GSA SPECT IGIP for stereotactic body radiotherapy (SBRT) in a patient with hepatocellular carcinoma (HCC).

CASE REPORT

A 60-year-old male developed obstructive jaundice caused by recurrent HCC in segment 1 after hepatic resection. He underwent repeated radiotherapy (RT) consisting of 45 Gy in 15 fractions 8 years ago and 30 Gy in 5 fractions 2 years ago. We performed SBRT consisting of 40 Gy in 8 fractions using ^99mTc-GSA SPECT-IGIP. We confirmed the dosimetric superiority of functional IGIP to conventional planning. He achieved complete response as assessed using the target volume. The patient has remained alive without recurrence for 18 months. He did not experience radiation-induced liver disease.

CONCLUSION

Recurrent HCC was successfully and safely salvaged via re-irradiation with SBRT using ^99mTc-GSA SPECT-IGIP.

Is Portal Vein Embolization Followed by Hepatectomy for Hepatocellular Carcinoma Justified in Patients with Impaired Liver Function?

BACKGROUND

Portal vein embolization (PVE) was developed for patients with insufficient future liver remnant volume and function and has gained relevant support worldwide before major hepatectomy. However, the efficacy of preoperative PVE for hepatocellular carcinoma (HCC) patients with impaired liver function remains uncertain.

PATIENTS AND METHODS

Ninety-seven HCC patients who were scheduled for PVE followed by hepatectomy were enrolled in this study. Their short- and long-term outcomes were investigated, according to the liver damage classification defined by the Liver Cancer Study Group of Japan.

RESULTS

Of 97 patients who underwent preoperative PVE, 30 (32.4%) could not undergo subsequent hepatectomy. Dropout rate from treatment strategy was significantly higher in patients with liver damage B (n = 13, 61.5%) than in those with liver damage A (n = 84, 26.2%) (P = 0.014). Among the 67 patients who underwent planned hepatectomy after PVE, 53 were categorized to liver damage A, and 14 were categorized to liver damage B at the point of hepatectomy. Although major complication and mortality rates were comparable between the two groups, the cumulative overall survival (OS) and disease-free survival (DFS) after hepatectomy were markedly worse in patients with liver damage B than in those with liver damage A (5-year OS rate: 23.1% vs 74.6%, P = 0.014, 5-year DFS rate: 7.8% vs 33.5%, P = 0.054, respectively).

CONCLUSIONS

The treatment strategy of PVE followed by hepatectomy might be a contraindication for HCC patients with impaired liver function categorized as liver damage B because of the higher dropout rate and poorer long-term outcomes after hepatectomy.

Preoperative three-dimensional versus two-dimensional evaluation in assessment of patients undergoing major liver resection for hepatocellular carcinoma: a propensity score matching study

Background

Compared with 2D evaluation, 3D evaluation possesses the virtues of displaying spatial anatomy of intrahepatic blood vessels and its relations to tumors, and enabling calculation of liver volumes, thus facilitating preoperative surgery planning.

Methods

The objective of this study is to study whether preoperative 3D (three-dimensional) evaluation produced better long-term overall survival (OS) outcomes compared to the traditional 2D (two-dimensional) evaluation in patients who underwent major hepatectomy for hepatocellular carcinoma (HCC). This retrospective study matched patients who underwent preoperative 2D evaluation with those who underwent preoperative 3D evaluation in a 1:1 ratio using propensity score matching. The primary endpoints were long-term survival outcomes in the two groups after major hepatectomy for HCC.

Results

Of the 248 patients in each of the 2 matched groups, the baseline characteristics were comparable. The median follow-up for all patients was 36 months (range, 0-40 months). The 3-year OS of patients in the PSM cohort was 38.5%. Compared with the 2D Group, patients in the 3D Group had a better OS rate (HR 0.722, 95% CI: 0.556-0.938, P=0.015) and disease-free survival (DFS) rate (HR 0.741, 95% CI: 0.590-0.929, P=0.009). The 3-year OS and DFS rate for the 3D Group versus the 2D group were 58.9% and 44.0% versus 47.4% and 33.1%, respectively.

Conclusions

3D preoperative evaluation resulted in significantly better intermediate-term (3-year) overall survival rate than the traditional 2D evaluation.

Preoperative Portal Vein Embolization in Hepatic Surgery: A Review about the Embolic Materials and Their Effects on Liver Regeneration and Outcome

Liver volume and function after hepatectomies are directly correlated to postoperative complications and mortality. Consequently contemporary liver surgery has focused on reaching an adequate future liver remnant so as to diminish postoperative morbidity and mortality. Portal vein embolization has evolved and is the standard of care as a liver regenerative strategy in many surgery departments worldwide before major liver resections. Different embolic materials have been used for portal vein embolization including gelfoam, ethanol, polyvinyl-alcohol particles, calibrated microspheres, central vascular plugs, coils, n-butyl-cyanoacrylate glue, fibrin glue, polidocanol-foam, alcoholic prolamin solution, and ethylene vinyl alcohol copolymer, as sole occluders or in varied combinations. While to date there has been no prospective controlled trial comparing the efficacy of different embolic materials in portal vein embolization, retrospective data insinuates that the use of n-butyl-cyanoacrylate and absolute ethanol produces higher contralateral liver hypertrophies. In this review, we evaluated publications up to August 2019 to assess the technical and regenerative results of portal vein embolization accomplished with different embolic materials. Special attention was given to specific aspects, advantages, and drawbacks of each embolic agent used for portal vein embolization, its liver regenerative performance, and its influence on patient outcome.

Radiomic detection of microscopic tumorous lesions in small animal liver SPECT imaging

BACKGROUND

Our aim was to present a new data analysis technique for the early detection of tumorous lesions using single-photon emission computed tomography (SPECT) imaging. Beyond standardized uptake value (SUV) and standardized uptake concentration (SUC), the skewness and kurtosis parameters of whole liver activity distribution histograms were examined in SPECT images to reveal the presence of tumorous cells.

METHODS

Four groups of mice were used in our experiment: a healthy control group, a group of obese mice with high body mass index, and two tumorous groups (primary liver cancer group with chemically induced hepatocellular carcinoma (HCC); metastatic liver tumor group-xenograft of human melanoma (HM)). For the SPECT measurements, ^99mTc-labeled aggregated albumin nanoparticles were administered intravenously 2 h before the liver SPECT scans (NanoSPECT/CT, Silver Upgrade, Mediso Ltd., Hungary) to image liver macrophages. Finally, SUV, SUC, skewness, and kurtosis of activity distributions were calculated from segmented whole liver volumes.

RESULTS

HCC animals showed moderate ^99mTc-albumin particle uptake with some visually identified cold spots indicating the presence of tumors. The visual detection of cold spots however was not a reliable marker of tumorous tissue in the metastatic group. The calculated SUV, SUC, and kurtosis parameters were not able to differentiate between the healthy and the tumorous groups. However, healthy and tumorous groups could be distinguished by comparing the skewness of the activity distribution.

CONCLUSION

Based on our results, ^99mTc-albumin nanoparticle injection followed by liver SPECT activity distribution skewness calculation is a suitable image analysis tool. This makes possible to effectively and quantitatively investigate liver macrophage inhomogeneity and identify invisible but present liver cold spot lesions. Skewness as a direct image-derived parameter is able to show altered tissue function even before the visual manifestation of liver tumor foci. The skewness of activity distribution might be related to an inhomogeneous distribution of macrophage cells as a consequence of microscopic tumor burden in the liver.

Impact of 99mTc-GSA SPECT Image-Guided Inverse Planning on Dose-Function Histogram Parameters for Stereotactic Body Radiation Therapy Planning for Patients With Hepatocellular Carcinoma: A Dosimetric Comparison Study

Purpose:

To evaluate the impact of ^99mTc-labeled diethylene triamine pentaacetate-galactosyl human serum albumin (^99mTc-GSA) single-photon emission computed tomography (SPECT) image-guided inverse planning on the dose–function histogram (DFH) parameters for stereotactic body radiation therapy planning in patients with hepatocellular carcinoma (HCC).

Methods:

Eleven patients were enrolled in this study. The functional liver structure (FLS) was derived from SPECT thresholds of 60% to 80% of the maximum pixel value. Two treatment plans optimized without FLS (plan C) and with FLS (plan F) were designed for 50 Gy to the planning target volume (PTV). The DFH parameters were calculated as follows: Fx = (sum of the counts within the liver volume receiving a dose >x Gy/sum of the counts within the whole liver volume) × 100. Other parameters for the PTV included D₉₅, mean dose, conformity index (CI), and homogeneity index (HI).

Results:

Compared with plan C, plan F significantly reduced DFH parameters of F₅ to F₄₀ (P < .05). There were no significant differences in the parameters of the PTV of D₉₅, mean dose, CI, and HI and organs at risks (stomach, duodenum, spinal cord, and kidneys) between plans C and F.

Conclusion:

DFH analyses revealed that ^99mTc-GSA SPECT image-guided inverse planning provided dosimetric benefits related to sparing of liver function and may reduce hepatic toxicities.

Is disease progression a contraindication for the strategy of portal vein embolization followed by hepatectomy for hepatocellular carcinoma?

BACKGROUND

Portal vein embolization has been used worldwide to induce hypertrophy of the future liver remnant and to reduce the risk of hepatic insufficiency and death after major hepatectomy. However, whether disease progression after portal vein embolization can affect long-term oncologic outcomes in patients with hepatocellular carcinoma is uncertain.

METHODS

From a total of 107 patients who underwent portal vein embolization and subsequent hepatectomy between 2000 and 2016, 57 patients with hepatocellular carcinoma were enrolled. We evaluated their long-term oncologic outcomes and investigated whether the disease progression between portal vein embolization and subsequent hepatectomy affected survival.

RESULTS

The 5-year overall survival and disease-free survival after hepatectomy were 74.5% and 31.7%, respectively. Multivariate analyses revealed that tumor number before hepatectomy ≥3 (hazard ratio 3.59, P = .019), des-γ-carboxy prothrombin >200 mAU/mL (hazard ratio 3.36, P = .045), and red blood cell transfusion (hazard ratio 11.03, P = .0008) were independent prognostic factors for overall survival. Male sex (hazard ratio 3.74, P = .029), bilobar tumor distribution (hazard ratio 3.65, P = .004), and red blood cell transfusion (hazard ratio 6.22, P = .0026) were independent prognostic factors for disease-free survival. Disease progressions after portal vein embolization, including increases in tumor size, tumor number, α-fetoprotein, lens culinaris agglutinin-reactive fraction of α-fetoprotein, and des-γ-carboxy prothrombin, were observed in 22.8%, 14.0%, 29.8%, 19.3%, and 47.4% of patients, respectively. Only an increase of tumor number significantly decreased the disease-free survival rate after hepatectomy in a univariate analysis, and none of the variables affected overall survival.

CONCLUSION

Disease progression after portal vein embolization did not affect long-term survival in patients with hepatocellular carcinoma if the planned subsequent hepatectomy could be completed.

Conversion therapy and suitable timing for subsequent salvage surgery for initially unresectable hepatocellular carcinoma: What is new?

AIM

To review the conversion therapy for initially unresectable hepatocellular carcinoma (HCC) patients and the suitable timing for subsequent salvage surgery.

METHODS

A PubMed search was undertaken from 1987 to 2017 to identify articles using the keywords including “unresectable” “hepatocellular carcinoma”, ”hepatectomy”, ”conversion therapy”, “resection”, “salvage surgery” and “downstaging”. Additional studies were investigated through a manual search of the references from the articles. The exclusion criteria were duplicates, case reports, case series, videos, contents unrelated to the topic, comments, and editorial essays. The main and widely used conversion therapies and the suitable timing for subsequent salvage surgery were discussed in detail. Two members of our group independently performed the literature search and data extraction.

RESULTS

Liver volume measurements [future liver remnant (FLR)/total liver volume or residual liver volume/bodyweight ratio] and function tests (scoring systems and liver stiffness) were often performed in order to justify whether patients were suitable candidates for surgery. Successful conversion therapy was usually defined as downstaging the tumor, increasing FLR and providing subsequent salvage surgery, without increasing complications, morbidity or mortality. The requirements for performing salvage surgery after transcatheter arterial chemoembolization were the achievement of a partial remission in radiology, the disappearance of the portal vein thrombosis, and the lack of extrahepatic metastasis. Patients with a standardized FLR (sFLR) > 20% were good candidates for surgery after portal vein embolization, while other predictive parameters like growth rate, kinetic growth rate were treated as an effective supplementary. There was probably not enough evidence to provide a standard operation time after associating liver partition and portal vein ligation for staged hepatectomy or yttrium-90 microsphere radioembolization. The indications of any combinations of conversion therapies and the subsequent salvage surgery time still need to be carefully and comprehensively evaluated.

CONCLUSION

Conversion therapy is recommended for the treatment of initially unresectable HCC, and the suitable subsequent salvage surgery time should be reappraised and is closely related to its previous therapeutic effect.

Preoperative Chemotherapy on Functional Liver Regeneration for Colorectal Liver Metastases Assessed With 99mTc-GSA SPECT/CT Imaging

Objective:

To investigate the functional liver regeneration after chemotherapy and liver resection for colorectal liver metastases (CRLM).

Background/Purpose:

Preoperative chemotherapy followed by liver resection for CRLM has been increasing; however, its negative impact on liver regeneration remains unknown.

Methods:

From January 2009 to December 2013, we enrolled 40 selected patients who underwent major hepatectomy without viral hepatitis and severe liver fibrosis. CRLM patients with preoperative chemotherapy (CT-CRLM group, n = 12) and patients without preoperative chemotherapy (control group, n = 28) were evaluated. Liver volume (LV) and functional liver volume (FLV) was assessed using Tc-99m–labeled galactosyl human serum albumin (99mTc-GSA) scintigraphy, single-photon emission computed tomography (SPECT), CT-fused images. Preoperative, future remnant liver, and post 1-month values were compared.

Results:

Median course of preoperative chemotherapy was 8 (range: 6–16). Preoperative background factors were almost identical including resection rate and functional resection rate. In the CT-CRLM group and in the control group, the percentage increases in LV were 39.3% ± 29.0% and 23.2% ± 23.5% (P = 0.037), and FLV were 79.4% ± 43.1% and 57.0% ± 33.4% (P = 0.417), respectively; absolute differences in LV were 216.2 ± 155.7 cm3 and 148.7 ± 134.7 cm3 (P = 0.086) and FLV were 19.4% ± 8.5%/m2 and 17.4% ± 7.9%/m2 (P = 0.235), respectively. We found no obvious tendency for negative influence on liver functional regeneration by the preoperative regimens for CRLM.

Conclusions:

Several courses of preoperative chemotherapy may not affect functional liver regeneration for CRLM patients after major hepatectomy.

Complete remission of advanced hepatocellular carcinoma following transient chemoembolization and portal vein ligation

Background

Macroscopic diffuse-type hepatocellular carcinoma with concomitant major portal vein tumor thrombus (PVTT) and peritoneal dissemination indicates poor prognosis. Additionally, triple-positive tumor marker status is a predictor of poor outcome even after hepatectomy. Sorafenib is recommended in such patients, but it has limited therapeutic effectiveness.

Case presentation

A 54-year-old man was diagnosed with a liver abscess that was treated by puncture and drainage at a regional hospital. However, the diagnosis was subsequently changed to hepatocellular carcinoma with macroscopic portal vein tumor thrombus, based on the results obtained for the triple-positive tumor markers (alpha-fetoprotein, 45,928 ng/ml; protein induced by vitamin K absence or antagonist-II, 125,350 mAU/ml; and alpha-fetoprotein-L3, 38.3%). As the patient’s liver functional reserve was not adequate for curative resection, chemoembolization was performed with a hepatic arterial infusion of cisplatin (50 mg) and 5-FU (1000 mg), followed by mild embolization with cisplatin (50 mg) suspended in lipiodol (5 ml) and starch microspheres (300 mg) containing mitomycin C (4 mg). As the thrombus had progressed to the bifurcation of the right and left portal veins, the right vein was surgically ligated. Three peritoneal nodules could be identified and were removed. Three additional rounds of hepatic arterial chemotherapy/chemoembolization were performed after the initial surgery. At the 2-year evaluation, all tumor markers were observed to have normalized and diagnostic imaging showed complete remission.

Conclusions

Complete remission of hepatocellular carcinoma with macroscopic portal vein tumor thrombus and peritoneal dissemination was obtained with a treatment regimen that involved four rounds of hepatic arterial infusion chemotherapy and transient chemoembolization, portal vein ligation, and the removal of peritoneal dissemination. This regimen can be recommended for patients with advanced hemiliver lesions who cannot undergo curative resection.

Heterogeneous liver uptake of Tc-99m-GSA as quantified through SPECT/CT helps to evaluate the degree of liver fibrosis: A retrospective observational study

Tc-99m-galactosyl human serum albumin (GSA) scintigraphy is used to assess the hepatic functional reserve, and allows for visual assessment of the residual hepatocyte distribution on single-photon emission computed tomography/computed tomography (SPECT/CT) images. The association between heterogeneous liver uptake of Tc-99m-GSA and liver fibrosis remains to be studied in detail. We analyzed this association.Fifty-one patients with chronic hepatobiliary disease undergoing a Tc-99m-GSA scintigraphy were included in this study. The receptor (LHL15) and blood clearance (HH15) indexes (the uptake ratios of the liver and heart) were obtained from dynamic planar images. The liver uptake count maximum-to-mean ratio (LUC Max/Mean) was calculated from single-photon emission computed tomography/computed tomography (SPECT/CT) images as an indicator of the Tc-99m-GSA liver uptake heterogeneity. We assessed the relationship between these quantified values and liver fibrosis.There were 30 Child-Pugh classification grade A patients, 16 grade B patients, and 5 grade C patients. Among the 30 patients whose liver histopathology was evaluable, those with advanced liver fibrosis (F2-4) had a lower LHL15 than those with mild liver fibrosis (F0-1) (median, 0.90 vs. 0.92, P = .04), and a higher LUC Max/Mean (median, 1.80 vs. 1.70, P = .02). The multivariate analysis identified platelets (P = .04) and the LUC Max/Mean (P = .04) as contributing factors of advanced liver fibrosis.These findings suggest that Tc-99m-GSA SPECT/CT can be used not only to assess the hepatic functional reserve, but also to evaluate a degree of liver fibrosis.

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.

Impact of liver volume and liver function on posthepatectomy liver failure after portal vein embolization- A multivariable cohort analysis

BACKGROUND

Liver failure remains a life-threatening complication after liver resection, and is difficult to predict preoperatively. This retrospective cohort study evaluated different preoperative factors in regard to their impact on posthepatectomy liver failure (PHLF) after extended liver resection and previous portal vein embolization (PVE).

METHODS

Patient characteristics, liver function and liver volumes of patients undergoing PVE and subsequent liver resection were analyzed. Liver function was determined by the LiMAx test (enzymatic capacity of cytochrome P450 1A2). Factors associated with the primary end point PHLF (according to ISGLS definition) were identified through multivariable analysis. Secondary end points were 30-day mortality and morbidity.

RESULTS

95 patients received PVE, of which 64 patients underwent major liver resection. PHLF occurred in 7 patients (11%). Calculated postoperative liver function was significantly lower in patients with PHLF than in patients without PHLF (67 vs. 109 μg/kg/h; p = 0.01). Other factors associated with PHLF by univariable analysis were age, future liver remnant, MELD score, ASA score, renal insufficiency and heart insufficiency. By multivariable analysis, future liver remnant was the only factor significantly associated with PHLF (p = 0.03). Mortality and morbidity rates were 4.7% and 29.7% respectively.

CONCLUSION

Future liver remnant is the only preoperative factor with a significant impact on PHLF. Assessment of preoperative liver function may additionally help identify patients at risk for PHLF.

Resection for Klatskin tumors: technical complexities and results

Klatskin's tumors, actually-redefined as perihilar cholangiocarcinoma (phCCA) do represent 50-70% of all CCAs and develop in a context of chronic inflammation and cholestasis of bile ducts. Surgical resection provides the only chance of cure for this disease but is technically challenging because of the complex, intimate and variable relationship between biliary and vascular structures at this location. Five years survival rates range between 25-45% (median 27-58 months) in case of R0 resection and 0-23% (median 12-21 months) in case of R1 resection respectively. It should be noted that the major costs of high radicality are represented by relative high morbidity and mortality rates (i.e., 20-66% and 0-9% respectively). Considering the fact that radical resection may represent the only curative treatment of phCCA, we focused our review on surgical planning and techniques that may improve resectability rates and outcomes for locally advanced phCCA. The surgical treatment of phCCA can be successful when following aspects have been fulfilled: (I) accurate preoperative diagnostic aimed to identify the tumor in all its details (localization and extension) and to study all the risk factors influencing a posthepatectomy liver failure (PHLF): i.e., liver volume, liver function, liver quality, haemodynamics and patient characteristics; (II) High end surgical skills taking in consideration the local extension of the tumor and the vascular invasion which usually require an extended hepatic resection and often a vascular resection; (III) adequate postoperative management aimed to avoid major complications (i.e., PHLF and biliary complications). These are technically challenging operations and must be performed in a high volume centres by hepato-biliary-pancreas (HBP)-surgeons with experience in microsurgical vascular techniques.

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.

99mTc-GSA肝受体显像在肝功能评估临床研究应用及进展

我国是肝病大国, 各种肝病严重影响人民健康, 手术是多种肝病的重要治疗手段之一. 术前肝功能评估对于手术方案制定发挥极为重要价值, 其中尤以三维定量肝功能成像技术备受临床关注. 近年来分子影像突飞猛进, 恰巧这也是核医学分子影像技术的优势所在. 大量研究证实新型肝细胞去唾液酸糖蛋白受体显像剂^99mTc-半乳糖基人血清白蛋白(^99mTc-galactosyl-human serum albumin, ^99mTc-GSA)能够于无创条件下较为准确地反映肝功能状态, 但现有研究尚处于初始阶段, 仍待深入的临床研究. 本文旨在系统阐述^99mTc-GSA单光子发射计算机断层成像肝受体显像基础上, 结合已有临床研究及新进展, 探索其潜在临床应用前景及未来发展动向.

Future remnant liver function as predictive factor for the hypertrophy response after portal vein embolization

BACKGROUND

Preoperative portal vein embolization is widely used to increase the future remnant liver. Identification of nonresponders to portal vein embolization is essential because these patients may benefit from associating liver partition and portal vein ligation for staged hepatectomy (ALPPS), which induces a more powerful hypertrophy response. ^99mTc-mebrofenin hepatobiliary scintigraphy is a quantitative method for assessment of future remnant liver function with a calculated cutoff value for the prediction of postoperative liver failure. The aim of this study was to analyze future remnant liver function before portal vein embolization to predict sufficient functional hypertrophy response after portal vein embolization.

METHODS

Sixty-three patients who underwent preoperative portal vein embolization and computed tomography imaging were included. Hepatobiliary scintigraphy was performed to determine pre-portal vein embolization and post-portal vein embolization future remnant liver function. Receiver operator characteristic analysis of pre-portal vein embolization future remnant liver function was performed to identify patients who would meet the post-portal vein embolization cutoff value for sufficient function (ie, 2.7%/min/m²).

RESULTS

Mean pre-portal vein embolization future remnant liver function was 1.80% ± 0.45%/min/m² and increased to 2.89% ± 0.97%/min/m² post-portal vein embolization. Receiver operator characteristic analysis in 33 patients who did not receive chemotherapy revealed that a pre-portal vein embolization future remnant liver function of ≥1.72%/min/m² was able to identify patients who would meet the safe future remnant liver function cutoff value 3 weeks after portal vein embolization (area under the curve = 0.820). The predictive value was less pronounced in 30 patients treated with neoadjuvant chemotherapy (area under the curve = 0.618). A total of 45 of 63 patients underwent liver resection, of whom 5 of 45 developed postoperative liver failure; 4 of 5 patients had a post-portal vein embolization future remnant liver function below the cutoff value for safe resection.

CONCLUSION

When selecting patients for portal vein embolization, future remnant liver function assessed with hepatobiliary scintigraphy can be used as a predictor of insufficient functional hypertrophy after portal vein embolization, especially in nonchemotherapy patients. These patients are potential candidates for ALPPS.

Evaluating the current surgical strategies for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related death worldwide. Despite careful surveillance programs and the development of antiviral therapy for hepatitis virus infection, the occurrence rate of HCC remains high. Liver resection and liver transplantation are mainstay curative treatments. Most patients with HCC have impaired liver function, and surgical treatment is always accompanied by the risk of decompensation of the remnant liver, especially when the volume of the remnant liver is too small and the liver function too low to meet metabolic demands. The mortality of liver resection has dramatically decreased over the last three decades from 20% to less than 5% due to the accumulation of knowledge of liver anatomy, perioperative management and preoperative assessment of liver function. Here we provide an overview of the multidisciplinary treatments and current standard treatment strategies for HCC, to explore the possibility of expanding surgical treatments beyond the current standards.

Recurrence-free survival of a hepatocellular carcinoma patient with tumor thrombosis of the inferior vena cava after treatment with sorafenib and hepatic resection

Sorafenib (Nexabar, Bayer, Berlin, Germany), one of multikinase inhibitors, can infrequently downstage advanced hepatocellular carcinoma (HCC). There are some reports that sorafenib in combination with other modalities, such as transcatheter arterial chemoembolization (TACE) or radiation therapy, could represent a bridge to surgery. We have observed a progressive HCC case with hepatic vein tumor thrombosis proceeding to the inferior vena cava (IVC-HVTT) convert to a state of feasible curative resection after a multidisciplinary treatment which included sorafenib. The patient underwent a successful resection in consequence of this therapy. A 45-year-old male with Hepatitis B Virus-associated chronic hepatitis was diagnosed as HCC with IVC-HVTT. To obtain oncological curative resection, we performed TACE, radiation therapy followed by administration of sorafenib (800 mg per day, total 72 g). The tumor including IVC-HVTT remarkably shrank, therefore, an extended posterior sectionectomy and total removal of the IVC-HVTT was successfully performed. The operation time was 736 minutes and the amount of intraoperative hemorrhage was 805 mL. No postoperative complication occurred. Adjuvant therapy with sorafenib was started four weeks after the operation and continued for 6 months (800 mg per day, total 144 g). The patient is alive without recurrence for about 4 years from the initial therapy. Multidisciplinary therapy including sorafenib, TACE, radiation, and hepatic resection may be an effective strategy to treat HCC patients with IVC-HVTT.

Simultaneous SPECT imaging of multi-targets to assist in identifying hepatic lesions

Molecular imaging technique is an attractive tool to detect liver disease at early stage. This study aims to develop a simultaneous dual-isotope single photon emission computed tomography (SPECT)/CT imaging method to assist diagnosis of hepatic tumor and liver fibrosis. Animal models of liver fibrosis and orthotopic human hepatocellular carcinoma (HCC) were established. The tracers of ¹³¹I-NGA and ^99mTc-3P-RGD₂ were selected to target asialoglycoprotein receptor (ASGPR) on the hepatocytes and integrin α_vβ₃ receptor in tumor or fibrotic liver, respectively. SPECT imaging and biodistribution study were carried out to verify the feasibility and superiority. As expected, ^99mTc-3P-RGD₂ had the ability to evaluate liver fibrosis and detect tumor lesions. ¹³¹I-NGA showed that it was effective in assessing the anatomy and function of the liver. In synchronized dual-isotope SPECT/CT imaging, clear fusion images can be got within 30 minutes for diagnosing liver fibrosis and liver cancer. This new developed imaging approach enables the acquisition of different physiological information for diagnosing liver fibrosis, liver cancer and evaluating residual functional liver volume simultaneously. So synchronized dual-isotope SPECT/CT imaging with ^99mTc-3P-RGD₂ and ¹³¹I-NGA is an effective approach to detect liver disease, especially liver fibrosis and liver cancer.

Measuring total liver function on sulfur colloid SPECT/CT for improved risk stratification and outcome prediction of hepatocellular carcinoma patients

Background

Assessment of liver function is critical in hepatocellular carcinoma (HCC) patient management. We evaluated parameters of [^99mTc] sulfur colloid (SC) SPECT/CT liver uptake for association with clinical measures of liver function and outcome in HCC patients.

Methods

Thirty patients with HCC and variable Child-Turcotte-Pugh scores (CTP A5-C10) underwent [^99mTc]SC SPECT/CT scans for radiotherapy planning. Gross tumor volume (GTV), anatomic liver volume (ALV), and spleen were contoured on CT. SC SPECT image parameters include threshold-based functional liver volumes (FLV) relative to ALV, mean liver-to-spleen uptake ratio (L/S_mean), and total liver function (TLF) ratio derived from the product of FLV and L/S_mean. Optimal SC uptake thresholds were determined by ROC analysis for maximizing CTP classification accuracy. Image metrics were tested for rank correlation to composite scores and clinical liver function parameters. Image parameters of liver function were tested for association to overall survival with Cox proportional hazard regression.

Results

Optimized thresholds on SC SPECT were 58 % of maximum uptake for FLV, 38 % for L/S_mean, and 58 % for TLF. TLF produced the highest CTP classification accuracy (AUC = 0.93) at threshold of 0.35 (sensitivity = 0.88, specificity = 0.86). Higher TLF was associated with lower CTP score: TLF_A = 0.6 (0.4–0.8) versus TLF_B = 0.2 (0.1–0.3), p < 10⁻⁴. TLF was rank correlated to albumin and bilirubin (|R| > 0.63). Only TLF >0.30 was independently associated with overall survival when adjusting for CTP class (HR = 0.12, 95 % CI = 0.02–0.58, p = 0.008).

Conclusions

SC SPECT/CT liver uptake correlated with differential liver function. TLF was associated with improved overall survival and may aid in personalized oncologic management of HCC patients.

Significance of functional hepatic resection rate calculated using 3D CT/99mTc-galactosyl human serum albumin single-photon emission computed tomography fusion imaging

AIM: To evaluate the usefulness of the functional hepatic resection rate (FHRR) calculated using 3D computed tomography (CT)/^99mTc-galactosyl-human serum albumin (GSA) single-photon emission computed tomography (SPECT) fusion imaging for surgical decision making.

METHODS: We enrolled 57 patients who underwent bi- or trisectionectomy at our institution between October 2013 and March 2015. Of these, 26 patients presented with hepatocellular carcinoma, 12 with hilar cholangiocarcinoma, six with intrahepatic cholangiocarcinoma, four with liver metastasis, and nine with other diseases. All patients preoperatively underwent three-phase dynamic multidetector CT and ^99mTc-GSA scintigraphy. We compared the parenchymal hepatic resection rate (PHRR) with the FHRR, which was defined as the resection volume counts per total liver volume counts on 3D CT/^99mTc-GSA SPECT fusion images.

RESULTS: In total, 50 patients underwent bisectionectomy and seven underwent trisectionectomy. Biliary reconstruction was performed in 15 patients, including hepatopancreatoduodenectomy in two. FHRR and PHRR were 38.6 ± 19.9 and 44.5 ± 16.0, respectively; FHRR was strongly correlated with PHRR. The regression coefficient for FHRR on PHRR was 1.16 (P < 0.0001). The ratio of FHRR to PHRR for patients with preoperative therapies (transcatheter arterial chemoembolization, radiation, radiofrequency ablation, etc.), large tumors with a volume of > 1000 mL, and/or macroscopic vascular invasion was significantly smaller than that for patients without these factors (0.73 ± 0.19 vs 0.82 ± 0.18, P < 0.05). Postoperative hyperbilirubinemia was observed in six patients. Major morbidities (Clavien-Dindo grade ≥ 3) occurred in 17 patients (29.8%). There was no case of surgery-related death.

CONCLUSION: Our results suggest that FHRR is an important deciding factor for major hepatectomy, because FHRR and PHRR may be discrepant owing to insufficient hepatic inflow and congestion in patients with preoperative therapies, macroscopic vascular invasion, and/or a tumor volume of > 1000 mL.

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

BACKGROUND

The objective of this study was to determine the utility of Tc-99m-diethylenetriamine-penta-acetic acid-galactosyl human serum albumin ((99m)Tc-GSA) single-photon emission computed tomography (SPECT)/CT fusion imaging for posthepatectomy remnant liver function assessment in hilar bile duct cancer patients.

METHODS

Thirty hilar bile duct cancer patients who underwent major hepatectomy with extrahepatic bile duct resection were retrospectively analyzed. Indocyanine green plasma clearance rate (KICG) value and estimated KICG by (99m)Tc-GSA scintigraphy (KGSA) and volumetric and functional rates of future remnant liver by (99m)Tc-GSA SPECT/CT fusion imaging were used to evaluate preoperative whole liver function and posthepatectomy remnant liver function, respectively. Remnant (rem) KICG (= KICG × volumetric rate) and remKGSA (= KGSA × functional rate) were used to predict future remnant liver function; major hepatectomy was considered unsafe for values <0.05. The correlation of remKICG and remKGSA with posthepatectomy mortality and morbidity was determined.

RESULTS

Although remKICG and remKGSA were not significantly different (median value: 0.071 vs 0.075), functional rates of future remnant liver were significantly higher than volumetric rates (median: 0.54 vs 0.46; P < .001). Hepatectomy was considered unsafe in 17% and 0% of patients using remKICG and remKGSA, respectively. Postoperative liver failure and mortality did not occur in the patients for whom hepatectomy was considered unsafe based on remKICG. remKGSA showed a stronger correlation with postoperative prothrombin time activity than remKICG.

CONCLUSION

(99m)Tc-GSA SPECT/CT fusion imaging enables accurate assessment of future remnant liver function and suitability for hepatectomy in hilar bile duct cancer patients.

Portal Vein Embolization Followed by Right-Side Hemihepatectomy for Hepatocellular Carcinoma Patients: A Japanese Multi-Institutional Study

BACKGROUND

Portal vein embolization (PVE) is useful to expand the indications of major hepatectomy; however, its oncologic effects are not fully understood. This study aimed to confirm the efficacy of preoperative PVE for hepatocellular carcinoma patients.

STUDY DESIGN

Between 2000 and 2012, five hundred and ten patients with hepatocellular carcinoma undergoing right-side hemihepatectomy were enrolled (PVE group, n = 162 and non-PVE group, n = 348). To equalize background factors, one-to-one propensity case-matched analysis and multivariate analysis were performed. Short- and long-term outcomes were evaluated.

RESULTS

Propensity score-matched patients, 148 in each group, were selected. The percentage of resected liver volume on admission was significantly greater in the PVE group (60.5% vs 48.3%; p < 0.001), but decreased considerably after PVE, from 60.5% to 50.3% (p < 0.001). The 5-year cumulative recurrence-free survival (36.4% vs 35.3%) and overall survival (58.6% vs 52.8%) rates were comparable. Extrahepatic recurrences were less common in the PVE group (18.1% vs 38.8%; p = 0.004). Independent prognostic factors for recurrence-free survival were morbidity (hazard ratio [HR] = 1.56), multiple tumors (HR = 1.97), red cell concentrate administration (HR = 1.57), older age (HR = 2.09), and massive portal invasion (HR = 2.33); and those for overall survival were morbidity (HR = 2.37), multiple tumors (HR = 1.71), and massive hepatic venous invasion (HR = 3.49).

CONCLUSIONS

Even though hepatocellular carcinoma patients who underwent preoperative PVE and right-side hemihepatectomy had a significantly larger resected liver volume on admission, they have a comparable long-term prognosis as patients with up front hepatectomy. In addition, PVE might decrease extrahepatic recurrences.

Stepwise approach to curative surgery using percutaneous transhepatic cholangiodrainage and portal vein embolization for severe bile duct injury during laparoscopic cholecystectomy: a case report

Laparoscopic cholecystectomy (LC) has been recently adapted to acute cholecystitis. Major bile duct injury during LC, especially Strasberg-Bismuth classification type E, can be a critical problem sometimes requiring hepatectomy. Safety and definitive treatment without further morbidities, such as posthepatectomy liver failure, is required. Here, we report a case of severe bile duct injury treated with a stepwise approach using ^99mTc-galactosyl human serum albumin (^99mTc-GSA) single-photon emission computed tomography (SPECT)/CT fusion imaging to accurately estimate liver function.

A 52-year-old woman diagnosed with acute cholecystitis underwent LC at another hospital and was transferred to our university hospital for persistent bile leakage on postoperative day 20. She had no jaundice or infection, although an intraperitoneal drainage tube discharged approximately 500 ml of bile per day. Recorded operation procedure showed removal of the gallbladder with a part of the common bile duct due to its misidentification, and each of the hepatic ducts and right hepatic artery was injured. Abdominal enhanced CT revealed obstructive jaundice of the left liver and arterial shunt through the hilar plate to the right liver. Magnetic resonance cholangiopancreatography revealed type E4 or more advanced bile duct injury according to the Bismuth-Strasberg classification. We planned a stepwise approach using percutaneous transhepatic cholangiodrainage (PTCD) and portal vein embolization (PVE) for secure right hemihepatectomy and biliary-jejunum reconstruction and employed ^99mTc-GSA SPECT/CT fusion imaging to estimate future remnant liver function. The left liver function rate had changed from 26.2 % on admission to 26.3 % after PTCD and 54.5 % after PVE, while the left liver volume rate was 33.8, 33.3, and 49.6 %, respectively. The increase of liver function was higher than that of volume (28.3 vs. 15.8 %). On postoperative day 63, the curative operation, right hemihepatectomy and biliary-jejunum reconstruction, was performed, and posthepatectomy liver failure could be avoided.

Careful consideration of treatment strategy for each case is necessary for severe bile duct injury with arterial injury requiring hepatectomy. The stepwise approach using PTCD and PVE could enable hemihepatectomy, and ^99mTc-GSA SPECT/CT fusion imaging was useful to estimate heterogeneous liver function.

A 5-year recurrence-free survivor with over ten colorectal liver metastases undergoing FOLFOX plus bevacizumab followed by two-stage hepatectomy

A 62-year-old male was admitted because of lower left abdominal pain and diarrhea. The patient was diagnosed with rectal cancer and multiple liver metastases. First, the laparoscopic Hartmann operation with a D3 lymph node dissection was performed. After five cycles of folinic acid, 5-fluorouracil and oxaliplatin (FOLFOX) and bevacizumab, and one additional FOLFOX, the tumor markers dramatically decreased; with carcinoembryonic antigen levels ranging from 1096.3 to 7.6 ng/ml and carbohydrate antigen 19-9 levels ranging from 3248.0 to 42.1 U/ml. Computed tomography showed a bilateral 14 colorectal liver metastases which indicated stable disease by the Response Evaluation Criteria In Solid Tumors (RECIST) criteria and optimal morphologic response. A two-stage hepatectomy was performed to complete a curative resection because of the insufficient remnant liver volume. Five partial hepatic resections in the left liver and the right portal vein ligation were performed during the first operation. Thirty-four days later, a right hepatectomy was successfully performed. Pathologically, there was tumor necrosis in 90 percent of the area of the metastasized liver, and viable cells were detected in only a marginal part of the liver. The patient had an uneventful postoperative course and was discharged fifteen days after the second operation. Uracil-tegafur plus leucovorin was administered for 6 months as an adjuvant chemotherapy treatment. The patient is currently alive and has remained disease-free for more than 5 years. In conclusion, an ideal combination of perioperative chemotherapy and curative resection may provide a chance of long-term survival without recurrence of disease for selected patients with more than ten bilateral colorectal liver metastases.

Changes in Liver Volume in Patients with Chronic Hepatitis C Undergoing Antiviral Therapy

AIM

Liver volumetric analysis has not been used to detect hepatic remodelling during antiviral therapy before. We measured liver volume (LV) changes on volumetric magnetic resonance imaging during hepatitis C antiviral therapy.

METHODS

22 biopsy-staged patients (median [range] age 45(19-65) years; 9F, 13M) with chronic hepatitis C virus infection were studied. LV was measured at the beginning, end of treatment and 6 months post-treatment using 3D T1-weighted acquisition, normalised to patient weight. Liver outlines were drawn manually on 4 mm thick image slices and LV calculated. Inter-observer agreement was analysed. Patients were also assessed longitudinally using biochemical parameters and liver stiffness using Fibroscan™.

RESULTS

Sustained viral response (SVR) was achieved in 13 patients with a mean baseline LV/kg of 0.022 (SD 0.004) L/kg. At the end of treatment, the mean LV/kg was 0.025 (SD 0.004, P = 0.024 cf baseline LV/kg) and 0.026 (SD 0.004, P = 0.008 cf baseline LV/kg) 6 months post-treatment (P = 0.030 cf baseline, P = 0.004). Body weight-corrected end of treatment LV change was significantly higher in patients with SVR compared to patients not attaining SVR (P = 0.050). End of treatment LV change was correlated to initial ALT (R (2) = 0.479, P = 0.037), but not APRI, AST, viral load or liver stiffness measurements. There was a correlation of 0.89 between observers for measured slice thickness.

CONCLUSIONS

LV increased during anti-viral treatment, while the body weight-corrected LV increase persisted post-antiviral therapy and was larger in patients with SVR.

Three-Dimensional Quantitative Evaluation of the Segmental Functional Reserve in the Cirrhotic Liver Using Multi-Modality Imaging

To quantitatively evaluate the regional functional reserve in the cirrhotic liver and to seek related index that reflects diminished segmental liver function. A 3D system for quantitative evaluation of the liver was used to fuse technetium-99m galactosyl human serum albumin single-photon emission computed tomography and computed tomography images from 20 patients with cirrhotic liver and hepatocellular carcinoma. A set of parameters reflecting liver function including morphological liver volume, functional liver volume, functional liver density (FLD), and the drug absorption rate constant for hepatic cells (GSA-K) was calculated. Differences in FLD and GSA-K in intrahepatic segments were compared in patients with a tumor embolus (Group Y) and those without such an embolus (Group N) in the right portal vein. Differences in FLD and GSA-K in tumor-bearing (T+ group) and tumor-free (T- group) segments in patients with no tumor embolus (Group N) were also compared. Eleven living donor liver transplantation donor served as the control group. The FLD of the liver as a whole was significantly lower in patients with cirrhosis than in the control group (0.53 ± 0.13 vs 0.68 ± 0.10, P = 0.010). The FLD in segments of the right hemiliver was significantly lower than that in segments of the left hemiliver in Group Y (0.31 ± 0.21 vs 0.58 ± 0.12, P = 0.002) but not in Group N (0.60 ± 0.19 vs 0.55 ± 0.13, P = 0.294). FLD was 0.45 ± 0.17 in the T+ group and 0.60 ± 0.08 in the T- group (P = 0.008). Differences in GSA-K in intrahepatic segments were not significant. In the control group, differences in FLD and GSA-K in intrahepatic segments were not significant. The segmental liver functional reserve can be quantitatively calculated. FLD, but not GSA-K, is an index that reflects diminished regional liver function caused by portal flow obstruction or tumor compression.

Effect of branched-chain amino acid supplementation on functional liver regeneration in patients undergoing portal vein embolization and sequential hepatectomy: a randomized controlled trial

BACKGROUND

Portal vein embolization (PVE) can decrease the resection ratio for major hepatectomy. (99m)Tc-galactosyl human serum albumin (GSA) scintigraphy is useful for evaluating quantitative functional liver volume. Branched chain amino acids (BCAAs) modulate liver function and regeneration. We analyzed the effects of BCAAs, in terms of liver function and regeneration after PVE, in combination with major hepatectomy.

METHODS

This randomized controlled trial was conducted for patients receiving PVE through to complete hepatectomy from September, 2011 to June, 2013. BCAA granules were added two times a day to a conventional diet in the BCAA administration group (BCAA group). The primary end point was functional liver regeneration of the future remnant liver after PVE followed by hepatic resection. Functional liver regeneration was assessed by the liver uptake value obtained from (99m)Tc-GSA scintigraphy single-photon-emission computed tomography/computed tomography fusion images. The secondary end points were volumetric liver regeneration and changes in liver function and laboratory data.

RESULTS

A BCAA group (n = 13) and a non-BCAA group (control group; n = 15) were included. The primary end point was partially met: the liver uptake value significantly increased in the BCAA group compared with the control group 6 months after hepatic resection (266.7% vs 77.6%, P = 0.04) and marginally increased after PVE (43.8% vs 17.4%, P = 0.079). Following PVE, the increment of the uptake ratio of the liver to the liver plus heart at 15 min was significantly less in the BCAA group than in the control group (0.0 and 0.01, P = 0.023).

CONCLUSIONS

BCAA supplementation improved functional liver regeneration and function in patients undergoing PVE followed by major hepatic resection.

Reliability and advantages of using non-uniform Chang's attenuation correction method using a CT-based attenuation coefficient map in (99m)Tc-GSA SPECT/CT hepatic imaging

BACKGROUND

Generally, attenuation correction is made by incorporating a linear attenuation coefficient, which is based on the attenuation coefficient map (mu-map) created from a computed tomography scan, into the ordered subsets-expectation maximization reconstruction method in non-uniform domains. A non-uniform Chang's attenuation correction method that uses the mu-map created from a computed tomography image that was made after reconstruction has been performed is currently available. The purpose of this study was to determine the usefulness of the non-uniform Chang's attenuation correction method in (99m)Tc-galactosyl human serum albumin diethylenetriamine pentaacetic acid single photon emission computed tomography/computed tomography imaging.

METHODS

Single photon emission computed tomography/computed tomography imaging was performed in phantoms with (99m)Tc water solutions and in a clinical study of 20 donors in living liver tissue transplantation. Attenuation correction was then performed in the reconstructed single photon emission computed tomography images with the non-uniform Chang's method and ordered subsets-expectation maximization attenuation correction methods with triple energy window scatter correction. Root mean square error values were used for assessment of the image uniformity, and we evaluated the absolute radioactivity in liver parts in the phantoms and those in the donors who had a normal liver function.

RESULTS

The values of root mean square error on the non-uniform Chang's attenuation correction images were lower than those on ordered subsets-expectation maximization attenuation correction images for both the phantoms and the 20 donors. The difference between the true and estimated radioactivity in the non-uniform Chang's attenuation correction method was smaller than that in the ordered subsets-expectation maximization attenuation correction methods in the phantom study.

CONCLUSIONS

The non-uniform Chang's attenuation correction is considered to be superior to the ordered subsets-expectation maximization attenuation correction in the assessment of absolute liver radioactivity and liver image uniformity on (99m)Tc-galactosyl human serum albumin diethylenetriamine pentaacetic acid single photon emission computed tomography/computed tomography imaging.

(99m)Tc-GSA SPECT/CT fused images for assessment of hepatic function and hepatectomy planning

To assure safe hepatectomy, accurate estimation of the functional reserve of the future remnant liver is crucial. The combination of indocyanine green retention rate at 15 min and CT volumetry is widely used in deciding on the extent of hepatectomy. On the other hand, there are quantitative indices calculated from (99m)Tc-GSA scintigraphy that reflect the number and function of hepatocytes. Therefore, there are many indices calculated from (99m)Tc-GSA scintigraphy that have been reported. In recent Annals of Surgical Oncology on Oct. 2014 the Uptake Index (UI) calculated from (99m)Tc-GSA scintigraphy was reported to be useful for hepatectomy planning and postoperative liver failure prediction. In this paper, we report on the usefulness and limits of quantitative indices calculated from (99m)Tc-GSA SPECT/CT for preoperative simulation.