Predictive value of Tc-99m galactosyl human serum albumin liver SPECT on the assessment of functional recovery after partial hepatectomy: a comparison with CT volumetry

Validation study on accuracy of our newly proposed methods for post-therapeutic liver reserve capacity estimation utilizing 99 mTc-GSA scintigraphy prior to carbon-ion radiotherapy

OBJECTIVE

Carbon-ion radiotherapy (CIRT) is known as a promising treatment for liver tumors. However, no method has been established for estimating post-therapeutic residual liver reserve capacity (pRLRC). We previously introduced the estimation method of pRLRC using 99 mTc-galactosyl human serum albumin (99 mTc-GSA) scintigraphy (Yamazaki method). In this study, we developed "Yamazaki-variant" method for pRLRC using dose distribution data of CIRT planning. The purpose of this study was to compare pRLRC calculated by Yamazaki method and Yamazaki-variant in CIRT patients for liver tumors, and to provide the clinical advantages in both methods in terms of estimating ability of pRLRC.

METHODS

Patients who received CIRT for liver tumors in our hospital and underwent 99 mTc-GSA scintigraphy before and 3 months after CIRT, and contrast-enhanced liver MRI within 1 month before CIRT were included. A total of 71 patients, 21 additional to the 50 previously reported, were evaluated. The maximal removal rate of 99 mTc-GSA (GSA-Rmax) was analyzed and the GSA-Rmax of the estimated residual liver (GSA-RL) was calculated using fusion images of MRI and SPECT by Yamazaki method. In Yamazaki-variant, multiple simulations were performed using the dose distribution of the CIRT planning and SPECT fusion images to obtain higher diagnostic accuracy of GSA-RL. Two of these estimates, Validation 1 and Validation 2 by Yamazaki-variant, were used as validation data. GSA-RL and Validation 1 and 2 were compared with GSA-Rmax 3 months after CIRT (post-GSA-Rmax) using linear regression analysis.

RESULTS

GSA-RL, Validation 1 and 2 were calculated as 0.448 ± 0.214, 0.413 ± 0.199 and 0.435 ± 0.208 mg/min, respectively. Post-GSA-Rmax was 0.428 ± 0.220 mg/min. The relationship between post-GSA-Rmax and each parameter was y = 0.02 + 0.90x (R2 = 0.78) for GSA-RL, y = 0.02 + 0.94x (R2 = 0.79) for Estimation 1, y = 0.02 + 0.99x (R2 = 0.80) for Estimation 2, respectively (P <.0001). Both Yamazaki method and Yamazaki-variant showed comparable accurate estimation ability for post-GSA-Rmax.

CONCLUSIONS

The estimation of pRLRC by Yamazaki method and Yamazaki-variant was in good agreement with post-therapeutic liver reserve capacity after CIRT, and there was no difference in the accuracy of the estimation. The usefulness of Yamazaki method, which is simpler and more clinically applicable, was confirmed.

TRIAL REGISTRATION

This study is registered in UMIN Clinical Trials Registry (UMIN-CTR) as UMIN study ID: UMIN000038328 and UMIN000049770, UMIN000038174.

Post-hepatectomy liver failure: A timeline centered review

BACKGROUND

Post-hepatectomy liver failure (PHLF) is a leading cause of postoperative mortality after liver surgery. Due to its significant impact, it is imperative to understand the risk stratification and preventative strategies for PHLF. The main objective of this review is to highlight the role of these strategies in a timeline centered way around curative resection.

DATA SOURCES

This review includes studies on both humans and animals, where they addressed PHLF. A literature search was conducted across the Cochrane Library, Embase, MEDLINE/PubMed, and Web of Knowledge electronic databases for English language studies published between July 1997 and June 2020. Studies presented in other languages were equally considered. The quality of included publications was assessed using Downs and Black's checklist. The results were presented in qualitative summaries owing to the lack of studies qualifying for quantitative analysis.

RESULTS

This systematic review with 245 studies, provides insight into the current prediction, prevention, diagnosis, and management options for PHLF. This review highlighted that liver volume manipulation is the most frequently studied preventive measure against PHLF in clinical practice, with modest improvement in the treatment strategies over the past decade.

CONCLUSIONS

Remnant liver volume manipulation is the most consistent preventive measure against PHLF.

Estimation of post-therapeutic liver reserve capacity using 99mTc-GSA scintigraphy prior to carbon-ion radiotherapy for liver tumors

BACKGROUND

There is currently no established imaging method for assessing liver reserve capacity prior to carbon-ion radiotherapy (CIRT) for liver tumors. In order to perform safe CIRT, it is essential to estimate the post-therapeutic residual reserve capacity of the liver.

PURPOSE

To evaluate the ability of pre-treatment 99mTc-galactosyl human serum albumin (99mTc-GSA) scintigraphy to accurately estimate the residual liver reserve capacity in patients treated with CIRT for liver tumors.

MATERIALS AND METHODS

This retrospective study evaluated patients who were performed CIRT for liver tumors between December 2018 and September 2020 and underwent 99mTc-GSA scintigraphy before and 3 months after CIRT, and gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced MRI within 1 month before CIRT were evaluated. The maximal removal rate of 99mTc-GSA (GSA-Rmax) was analyzed for the evaluation of pre-treatment liver reserve capacity. Then, the GSA-Rmax of the estimated residual liver (GSA-RL) was calculated using liver SPECT images fused with the Gd-EOB-DTPA-enhanced MRI. GSA-RL before CIRT and GSA-Rmax at 3 months after CIRT were compared using non-parametric Wilcoxon signed-rank test and linear regression analysis.

RESULTS

Overall, 50 patients were included (mean age ± standard deviation, 73 years ± 11; range, 29-89 years, 35 men). The median GSA-RL was 0.393 [range, 0.057-0.729] mg/min, and the median GSA-Rmax after CIRT was 0.369 [range, 0.037-0.780] mg/min (P = .40). The linear regression equation representing the relationship between the GSA-RL and GSA-Rmax after CIRT was y = 0.05 + 0.84x (R2 = 0.67, P < .0001). There was a linear relationship between the estimated and actual post-treatment values for all patients, as well as in the group with impaired liver reserve capacity (y = - 0.02 + 1.09x (R2 = 0.62, P = .0005)).

CONCLUSIONS

99mTc-GSA scintigraphy has potential clinical utility for estimating the residual liver reserve capacity in patients undergoing carbon-ion radiotherapy for liver tumors.

TRIAL REGISTRATION

UMIN000038328, https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000043545 .

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.

Significance of the preoperative regional maximal removal rate of technetium-99m-galactosyl human serum albumin in the future remnant liver: a sequential study of regional maximal removal rate of technetium-99m-galactosyl human serum albumin in the whole liver

BACKGROUND

The relationship between posthepatectomy complications and liver functional parameters was preliminary reported in a pilot study. The present study sequentially evaluated the clinical significance of maximal removal rate of technetium-99m-galactosyl human serum albumin (GSARmax) in the future remnant liver (rGSARmax) in patients to predict posthepatectomy complications.

METHODS

Between 2010 and August 2017, GSARmax, rGSARmax, their difference (Dif), and the rGSARmax to GSARmax ratio were examined in 247 additional patients who underwent hepatectomy for liver and biliary diseases. Hepatectomy-related postoperative complications (i.e. long-term ascites, intra-abdominal infection, and hepatic failure) occurred in 73 (29.6%) patients.

RESULTS

The median and mean preoperative GSARmax values were 0.477 and 0.498±0.166 mg/min, respectively; rGSARmax values were 0.341 and 0.366±0.145 mg/min, respectively; Dif values were 0.105 and 0.132±0.111 mg/min, respectively; and the rGSARmax to GSARmax ratio values were 0.774 and 0.746±0.177, respectively. Among these, the GSARmax and rGSARmax values were significantly correlated with the liver functional parameters ICGR15, LHL15, HH15, prothrombin activity, serum hyaluronic acid level, and platelet count (all P<0.01). The rGSARmax values were significantly lower in patients with long-term ascites (P<0.05), and the predictive cutoff values of rGSARmax were 0.290 mg/min; however, the multivariate logistic regression analysis showed that rGSARmax was not independently related to long-term ascites.

CONCLUSION

When accompanied by other functional liver reserve parameters, rGSARmax seemed to be an alternative liver functional parameter related to ascites.

Prediction of Posthepatectomy Liver Failure Proposed by the International Study Group of Liver Surgery: Residual Liver Function Estimation With 99mTc-Galactosyl Human Serum Albumin Scintigraphy

PURPOSE

The International Study Group of Liver Surgery (ISGLS) proposed a definition and grading system for posthepatectomy liver failure (PHLF). We evaluated the usefulness of residual liver function estimation using Tc-galactosyl human serum albumin (Tc-GSA) for the prediction of PHLF.

METHODS

Patients with liver tumors (n = 136) and scheduled for hepatectomy underwent Tc-GSA scintigraphy. Based on their imaging data, the maximal GSA removal rate (GSA-Rmax)was calculated using multicompartment analysis. We also calculated GSA-Rmax in the predicted residual liver (GSA-RL) whose volume was determined on computed tomography (CT) scans. We compared the age, sex, 15-minute indocyanine green retention rate; albumin, bilirubin, hyaluronic acid, and type 4 collagen levels; the Child-Pugh classification; residual liver volume; residual liver percentage; GSA-Rmax; and GSA-RL in patients with and without PHLF. Univariate and multivariate logistic analyses were used for statistical assessments.

RESULTS

Of 136 patients, 17 (12.5%) met the ISGLS criteria for PHLF (ISGLS-PHLF). There was a statistically significant difference in the age, albumin level, Child-Pugh classification, residual liver volume, residual liver percentage, GSA-Rmax, and GSA-RL between patients with and without PHLF. Based on multivariate analysis, GSA-RL and the residual liver volume were significant independent predictors of ISGLS-PHLF (P = 0.004 and P = 0.038, respectively). The odds ratio was 149423 for GSA-RL and 1.003 for the residual liver volume.

CONCLUSIONS

GSA-RL calculated using Tc-GSA scintigraphy was the most useful independent predictor for ISGLS-PHLF.

Preoperative regional maximal removal rate of technetium-99m-galactosyl human serum albumin is correlated with liver functional parameters, but did not predict postoperative morbidity

BACKGROUND

Recently, posthepatectomy complications have been predicted by advances of new liver functional parameters, and the technetium-99m-galactosyl human serum albumin (GSA) liver scintigraphy has been applied widely for this purpose. We evaluated the clinical significance of the regional maximal removal rate (GSA-Rmax) in patients with various liver diseases as predictors of posthepatectomy complications.

PATIENTS AND METHODS

Between 2012 and March 2016, we examined 200 patients who underwent hepatectomy for liver and biliary diseases. The patients' background liver conditions included chronic viral liver diseases in 147 patients, normal liver in 44 patients, and others in nine patients. Hepatectomy-related postoperative complications (i.e. long-term ascites, intra-abdominal infection, and hepatic failure) occurred in 69 (35%) patients. A multivariate logistic analysis was carried out to detect the predictive parameters for complications.

RESULTS

The median and mean preoperative GSA-Rmax was 0.420 and 0.448±0.148 mg/min, respectively. The GSA-Rmax was significantly correlated with liver functional parameters of ICGR15, LHL15, HH15, platelet count, prothrombin activity, and serum hyaluronic acid level (P<0.01), and was significantly correlated with postoperative total bilirubin level and C-reactive protein level (P<0.05). With respect to patient outcomes, GSA-Rmax was significantly lower in patients with long-term ascites (P<0.05). The predictive cutoff value for posthepatectomy long-term ascites for GSA-Rmax was 0.421 mg/min. However, the multivariate logistic regression analysis identified that a higher serum hyaluronic acid level and a lower platelet count were significant, independent factors, but not lower GSA-Rmax.

CONCLUSION

GSA-Rmax is one of the liver functional parameters and is a complementary parameter to predict postoperative hyperbilirubinemia, inflammatory responses, and ascites when Tc-GSA scintigraphy is performed.

Impaired Value of 99m Tc-GSA Scintigraphy as an Independent Risk Factor for Posthepatectomy Liver Failure in Patients with Hepatocellular Carcinoma

BACKGROUND

Posthepatectomy liver failure (PHLF) was recently defined with the corresponding recommendations as follows: grade A, no change in clinical management; grade B, clinical management with noninvasive treatment; and grade C, clinical management with invasive treatment. In this study, we identified the risk factors for grade B and C PHLF in patients with hepatocellular carcinoma (HCC).

METHODS

Of 339 HCC patients who underwent curative hepatic resection, 218 were included for analysis. The LHL15 index (uptake ratio of the liver to that of the liver and heart at 15 min) was measured by 99m Tc-GSA (99m technetium-labelled galactosyl human serum albumin); remnant LHL15 was calculated as LHL15 × [1 - (resected liver weight - tumor volume)/whole liver volume without tumor].

RESULTS

A total of 163 patients were classified as having no PHLF, whereas 17, 37, and 1 patient had PHLF grade A, B, and C, respectively. There were significant differences in indocyanine green R15, serum albumin, prothrombin time, Child-Pugh classification, LHL15 and remnant LHL15 between patients with grades B/C PHLF and patients with grade A or no PHLF. Only remnant LHL15 was identified as an independent risk factor for grades B/C PHLF (p = 0.023), with a cut-off value of 0.755.

CONCLUSIONS

Remnant LHL15 was an independent risk factor for grades B/C PHLF. Patients with impaired remnant LHL15 value of <0.755 should be carefully monitored for PHLF.

Preoperative maximal removal rate of technetium-99m-galactosyl-human serum albumin of the remnant liver is associated with postoperative tumor relapse in hepatitis C virus-related hepatocellular carcinoma

BACKGROUND

Prognosis in patients with hepatocellular carcinoma (HCC) is not only influenced by tumor-related factors but also by the background liver functions. The maximal removal rate of technetium-99m-galactosyl human serum albumin (GSA-Rmax) of the remnant liver (rGSA-Rmax) is a useful candidate for predicting the liver function and clarifying the relationship between the remnant liver functional reserve and tumor-free survival in patients who have undergone hepatectomy.

PATIENTS AND METHODS

One hundred and sixty-five patients with HCC who underwent curative hepatectomy were divided into three groups of hepatitis B virus (B-HCC; n=42), hepatitis C virus (C-HCC, n=58), and non-B, non-C (NBNC-HCC, n=65). The relationship between rGSA-Rmax and survival was examined by univariate and multivariate analyses.

RESULTS

In the C-HCC group, the albumin, or LHL15, level was significantly lower, and alanine aminotransferase, ICGR15, and the prevalence of grade B liver damage were significantly higher than other two groups (P<0.05). GSA-Rmax or rGSA-Rmax was not different between the three groups. Lower GSA-Rmax and rGSA-Rmax were only significantly associated with lower tumor-free survival in the C-HCC group by the univariate analysis (P<0.05) but not significantly by the multivariate analysis.

CONCLUSION

GSA-Rmax and rGSA-Rmax reflect the severity of liver dysfunction and furthermore, the lower rGSA-Rmax is useful as a complementary factor to predict the early HCC recurrence after hepatectomy.

Advances in preoperative assessment of liver function

BACKGROUND

Postoperative liver failure remains a life-threatening complication. Preoperative evaluation of liver function is essential in reducing the complications after hepatectomy. However, it is difficult to accurately evaluate liver function before surgery because of the limitations of the liver function tests available. Recent advances in liver function tests improved the ability to assess liver function. The present review was to analyze these methods and their advantages.

DATA SOURCES

MEDLINE was searched using the terms of "liver function test", "liver function evaluation" and "galactosyl serum albumin". Relevant articles published in English and Chinese from 1961 to 2014 were reviewed.

RESULTS

Although serological tests are used frequently in practice, they reflect the degree of total liver damage or function, not the remnant of liver function. Child-Pugh score and model for end-stage liver disease (MELD) score assess whole liver function, and are particularly useful in determining whether patients with hepatocellular carcinoma and cirrhosis are candidates for resection or transplantation, but cannot determine the safe extent or removal. The indocyanine green and other metabolic quantitative liver function tests can evaluate functional hepatocytes, making them more accurate in predicting liver function. Computed tomography (CT) volumetry can provide anatomic information on the remnant liver volume but not on functional volume. 99mTc-galactosyl serum albumin scintigraphy, combined with single photon emission computed tomography, CT and three-dimensional reconstruction, may be a better quantitative measure of liver function, especially of remnant liver function.

CONCLUSIONS

Tests used to evaluate liver functional reserve and to predict surgical risk have limitations. 99mTc-galactosyl serum albumin scintigraphy, which can more accurately evaluate the whole and regional liver function, may be promising in predicting resection margins and risks of liver failure.

CT volumetry of the liver: where does it stand in clinical practice?

Imaging-based volumetry has been increasingly utilised in current clinical practice to obtain accurate measurements of the liver volume. This is particularly useful prior to major hepatic resection and living donor liver transplantation where the size of the remnant liver and liver graft, respectively, affects procedural success and postoperative mortality and morbidity. The use of imaging-based volumetry, with emphasis on computed tomography, will be reviewed. We will explore the various technical factors that contribute to accurate volumetric measurements, and demonstrate how the accuracies of these techniques are influenced by their methodologies. The strengths and limitations of using anatomical imaging to estimate liver volume will be discussed, in relation to laboratory and functional imaging methods of assessment.

Correction of liver displacement due to irregular respiration for SPECT images obtained using a multiple short-time acquisition with breath-holding technique

Recently, a new method for acquiring single photon emission computed tomography (SPECT) data during breath-holding with a high-speed rotation (HSR-SPECT) technique was applied to hepatic-function scintigraphy. This technique can suppress motion artifact caused by respiration. However, it is challenging to apply this technique to patients with respiratory problems. Our purpose in this study was to analyze projection data and correct liver displacement due to irregular respiration during technetium-99m-diethylenetriaminepentaacetic acid galactosyl human serum albumin ((99m)Tc-GSA) liver SPECT scans. We calculated cross-correlation functions (CCFs) for both intra- and inter-projections to correct irregular projections by shifting them in the longitudinal direction enough to maximize the CCFs. We integrated all of the shifted projections and created a synthesis projection which was used to reconstruct SPECT images. To confirm the effectiveness of our method, we did both a phantom study and a clinical retrospective review. In the phantom study, blurring artifacts due to displacement were reduced using our method. Post-processing using our method showed improvements in the normalized mean square error values ranging from 0.18 to 0.06. Furthermore, our method showed no disadvantage or miss-correction if we applied our method to data without displacement. In the clinical review, our method improved the image clarity for patients who could not repeat consistent respiration. In both the phantom simulation and the clinical application, the results showed the usefulness of our method. The efficiency of our method has the potential to reduce the displacement problem caused by respiration and provides excellent matching SPECT/CT fusion images.