Nontumorous decrease in Tc-99m GSA accumulation

Indocyanine green plasma clearance rate and 99mTc-galactosyl human serum albumin single-photon emission computed tomography evaluated preoperative remnant liver

BACKGROUND

Preoperative evaluation of future remnant liver reserves is important for safe hepatectomy. If the remnant is small, preoperative portal vein embolization (PVE) is useful. Liver volume analysis has been the primary method of preoperative evaluation, although functional examination may be more accurate. We have used the functional evaluation liver using the indocyanine green plasma clearance rate (KICG) and 99mTc-galactosyl human serum albumin single-photon emission computed tomography (99mTc-GSA SPECT) for safe hepatectomy.

AIM

To analyze the safety of our institution’s system for evaluating the remnant liver reserve.

METHODS

We retrospectively reviewed the records of 23 patients who underwent preoperative PVE. Two types of remnant liver KICG were defined as follows: Anatomical volume remnant KICG (a-rem-KICG), determined as the remnant liver anatomical volume rate × KICG; and functional volume remnant KICG (f-rem-KICG), determined as the remnant liver functional volume rate based on 99mTc-GSA SPECT × KICG. If either of the remnant liver KICGs were > 0.05, a hepatectomy was performed. Perioperative factors were analyzed. We defined the marginal group as patients with a-rem-KICG of < 0.05 and a f-rem-KICG of > 0.05 and compared the postoperative outcomes between the marginal and not marginal (both a-rem-KICG and f-rem-KICG > 0.05) groups.

RESULTS

All 23 patients underwent planned hepatectomies. Right hepatectomy, right trisectionectomy and left trisectionectomy were in 16, 6 and 1 cases, respectively. The mean of blood loss and operative time were 576 mL and 474 min, respectively. The increased amount of f-rem-KICG was significantly larger than that of a-rem-KICG after PVE (0.034 vs 0.012, P = 0.0273). The not marginal and marginal groups had 17 (73.9%) and 6 (26.1%) patients, respectively. The complications of Clavian-Dindo classification grade II or higher and post-hepatectomy liver failure were observed in six (26.1%) and one (grade A, 4.3%) patient, respectively. The 90-d mortality was zero. The marginal group had no significant difference in postoperative outcomes (prothrombin time/international normalised ratio, total bilirubin, complication, post-hepatectomy liver failure, hospital stay, 90-d, and mortality) compared with the not-marginal group.

CONCLUSION

Functional evaluation of the remnant liver enabled safe hepatectomy and may extend the indication for hepatectomy after PVE treatment.

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.

Functional discrepancy between two liver lobes after hemilobe biliary drainage in patients with jaundice and bile duct cancer: an appraisal using (99m)Tc-GSA SPECT/CT fusion imaging

PURPOSE

To determine the functional discrepancy between the two liver lobes using technetium 99m ((99m)Tc) diethylenetriamine-pentaacetic acid-galactosyl human serum albumin ( GSA diethylenetriamine-pentaacetic acid-galactosyl human serum albumin ) single photon emission computed tomography (SPECT)/computed tomography (CT) fusion imaging following preoperative biliary drainage and portal vein embolization ( PVE portal vein embolization ) in patients with jaundice who have bile duct cancer ( BDC bile duct cancer ).

MATERIALS AND METHODS

This retrospective study was approved by the institutional review board, with waiver of informed consent. Preoperative (99m)Tc- GSA diethylenetriamine-pentaacetic acid-galactosyl human serum albumin SPECT/CT fusion images from 32 patients with extrahepatic BDC bile duct cancer were retrospectively reviewed. Patients were classified into four groups according to the extent of biliary drainage and presence of a preoperative right PVE portal vein embolization : right lobe drainage group (right drainage), bilateral lobe drainage group (bilateral drainage), left lobe drainage group (left drainage), and left lobe drainage with right PVE portal vein embolization group (left drainage with right PVE portal vein embolization ). Percentage volume and percentage function were measured in each lobe using fusion imaging. The ratio between percentage function and percentage volume (the function-to-volume ratio) was calculated for each lobe, and the results were compared among the four groups. Statistical analysis was performed with Wilcoxon signed-rank tests and Mann-Whitney U tests.

RESULTS

The median values for the function-to-volume ratio in the right drainage, bilateral drainage, left drainage, and left drainage with right PVE portal vein embolization group were 1.12, 1.05, 1.02, and 0.81 in the right lobe; and 0.51, 0.88, 0.96, and 1.17 in the left lobe. Significant differences in the function-to-volume ratio were observed among the four groups (right drainage vs bilateral drainage vs left drainage vs left drainage with right PVE portal vein embolization ; with P < .002, P = .023, and P < .002 for the right lobe and P < .001, P = .023, and P < .002 for the left lobe).

CONCLUSION

Hepatic lobar function significantly differs between the two lobes, depending on the extent of biliary drainage and the presence of portal vein embolization.

CT/99mTc-GSA SPECT fusion images demonstrate functional differences between the liver lobes

AIM: To evaluate the functional differences between the 2 liver lobes in non-cirrhotic patients by using computed tomography/^99mTc-galactosyl human serum albumin (CT/^99mTc-GSA) single-photon emission computed tomography (SPECT) fusion images.

METHODS: Between December 2008 and March 2012, 264 non-cirrhotic patients underwent preoperative liver function assessment using CT/^99mTc-GSA SPECT fusion images. Of these, 30 patients, in whom the influence of a tumor on the liver parenchyma was estimated to be negligible, were selected. Specifically, the selected patients were required to meet either of the following criteria: (1) the presence of an extrahepatic tumor; or (2) presence of a single small intrahepatic tumor. These 30 patients were retrospectively analyzed to calculate the percentage volume (%Volume) and the percentage function (%Function) of each lobe. The ratio between the %Function and %Volume (function-to-volume ratio) of each lobe was also calculated, and the ratios were compared between the 2 lobes. Furthermore, the correlations between the function-to-volume ratio and each of 2 liver parameters [lobe volume and diameter ratio of the left portal vein to the right portal vein (LPV-to-RPV diameter ratio)] were investigated.

RESULTS: The median values of %Volume and %Function were 62.6% and 67.1% in the right lobe, with %Function being significantly higher than %Volume (P < 0.01). The median values of %Volume and %Function were 31.0% and 28.7% in the left lobe, with %Function being significantly lower than %Volume (P < 0.01). The function-to-volume ratios of the right lobe (1.04-1.14) were significantly higher than those of the left lobe (0.74-0.99) (P < 0.01). The function-to-volume ratio showed no significant correlation between the lobe volume in either lobe. In contrast, the function-to-volume ratio showed significant correlations with the LPV-to-RPV diameter ratio in both lobes (right lobe: negative correlation, r_s = -0.37, P = 0.048; left lobe: positive correlation, r_s = 0.71, P < 0.001). The function-to-volume ratio in the left lobe tended to be higher, and that in the right lobe tended to be lower, in accordance with the increase in the LPV-to-RPV diameter ratio.

CONCLUSION: CT/^99mTc-GSA SPECT fusion images demonstrated that the function of the left lobe was significantly decreased compared with that of the right lobe in non-cirrhotic livers.

Characteristics of three cases of hepatocellular carcinoma showing enhanced technetium-99m-diethylenetriaminepentaacetic acid-galactosyl human serum albumin accumulation by single photon emission computed tomography analysis

BACKGROUND

The asialoglycoprotein receptor (ASGP-R) is abundantly expressed on the sinusoidal surfaces of hepatocytes. However, the majority of hepatocellular carcinomas (HCC) lack ASGP-R on their cell surface membranes. We describe three cases of HCC showing increased expression of ASGP-R in comparison with the surrounding liver tissue.

METHODS

We performed technetium-99m-diethylenetriaminepentaacetic acid-galactosyl human serum albumin ((99m)Tc-GSA) single photon emission computed tomography (SPECT) analysis on patients with HCC. Three cases of HCC showing enhanced accumulation of (99m)Tc-GSA were included in the present study. Histopathological and radiological examinations of the HCC were conducted. The three affected patients were all female and over 60 years old.

RESULTS

Computed tomography (CT) angiography or dynamic CT showed hypo-enhancement of the tumors during the hepatic arterial to portal phases. Patient 1 received percutaneous ethanol injection therapy and died 5 years later because of chronic renal failure. Patient 2 underwent surgeryand is currently healthy 5 years after the operation. Patient 3 underwent percutaneous ethanol injection therapy and died 4 years later because of a newly occurred HCC to another part of the liver. Histopathological examination showed well-differentiated HCC in all three cases. Immunohistochemical examination showed that the expression of ASGP-R was higher in the HCC than in the non-tumorous liver tissue.

CONCLUSION

We have named the HCC of this type ASGP-Roma. ASGP-Roma is well-differentiated HCC, shows CT findings that are atypical of HCC, and is diagnosed by (99m)Tc-GSA SPECT analysis. We propose that ASGP-Roma be placed in a special category among well-differentiated HCC.

Hepatectomy simulation discrepancy between radionuclide receptor imaging and CT volumetry: influence of decreased unilateral portal venous flow

BACKGROUND

Regional dysfunction demonstrated by Tc-99m-diethylenetriamine-penta-acetic acid-galactosyl human serum albumin (GSA) scintigraphy due to regional decrease in the portal venous flow has previously been reported. In this study, we call attention to the significance of unilateral portal venous flow decrease for preoperative hepatectomy simulation, and evaluate the hepatectomy simulation discrepancy between Tc-99m-GSA single-photon emission computed tomography (SPECT) and CT volumetry.

METHODS

Twenty-four hepatectomy candidates underwent preoperative hepatectomy simulation by both Tc-99m-GSA SPECT and CT volumetry. Both anatomical and functional resection ratios were calculated by means of CT volumetry and Tc-99m-GSA SPECT, respectively. The differences and ratios between anatomical and functional resection ratios were calculated in all patients, and compared in patients with and without unilateral portal venous flow decrease.

RESULTS

Anatomical resection ratios were 28.0 +/- 11.7 (mean +/- standard deviation) in patients with unilateral portal venous flow decrease, and 42.1 +/- 15.7 in patients without unilateral portal venous flow decrease (p = 0.0127). Functional resection ratios were 14.7 +/- 12.8 in patients with unilateral portal venous flow decrease and 40.5 +/- 14.6 in patients without (p = 0.0004). The differences between anatomical and functional resection ratios were 13.0 +/- 7.9 in patients with unilateral portal venous flow decrease and 5.6 +/- 3.1 in patients without (p = 0.0099). The ratios between anatomical and functional resection ratios were 0.48 +/- 0.29 in patients with unilateral portal venous flow decrease and 0.86 +/- 0.10 in patients without (p = 0.0018). In 12 of the 13 patients with unilateral portal venous flow decrease, anatomical resection ratios were found to be larger than functional resection ratios, whereas this happened in only 6 of 11 patients without unilateral portal venous flow decrease (p = 0.0063).

CONCLUSION

Unilateral portal venous flow decrease is suspected to be a major factor in the discrepancy between hepatectomy simulations with radionuclide receptor imaging and CT volumetry.

Regional radioactivity discrepancy between Tc-99m GSA and Tc-99m phytate liver scans in a patient with massive hepatic necrosis

A 22-year-old woman with severe acute hepatitis underwent a Tc-99m galactosyl human serum albumin (GSA) scan. Intense accumulation was observed in the cephalic region of the right hepatic lobe, whereas the accumulation was reduced in the left lobe and the caudal region of the right lobe. A computed tomographic (CT) scan showed that the left lobe and the caudal region of the right posterior segment had atrophied and become hypodense, which were thought to represent postnecrotic scarring after massive hepatic necrosis. The relatively hyperdense region in the right lobe was slightly swollen and was thought to represent regenerating liver tissue or a "potato liver." Compared with the CT, the regions of elevated Tc-99m GSA accumulation correlated well with the areas of regenerating liver tissue, and the regions with reduced accumulation corresponded closely with the areas of postnecrotic scarring. On a Tc-99m phytate scan, unlike the Tc-99m GSA scan, the radiocolloid accumulation was intense in the left lobe and caudal region of the right lobe and reduced in the cephalic region of the right lobe. Together, the Tc-99m GSA scan and the Tc-99m phytate scan formed a set of exact "nega-posi" images. Biopsy specimens obtained during laparoscopy showed a few hepatocyte columns in the postnecrotic scarred left lobe. Severe disruption of the hepatocytes, prominent inflammatory cell infiltration, and obvious Kupffer cell hypertrophy and clustering were also observed.