Technetium-99m-galactosyl-neoglycoalbumin combined with iodine-123-Tyr-(A14)-insulin visualizes human hepatocellular carcinomas.
Human hepatocellular carcinoma (HCC) is the most frequent primary hepatic malignancy and its diagnosis by conventional methods is still difficult. We hypothesized that the expression of specific receptors could possibly be used to improve in vivo localization of HCC with specific receptor-based radioligands.


METHODS
In initial in vitro studies, receptor binding of 99mTc-galactosyl-neoglycoalbumin (99mTc-NGA) and 123I-Tyr-(A14)-insulin to HCC was investigated. Scintigraphy was performed in 45 patients with histologically confirmed HCC using either 99mTc-NGA (75-150 MBq; 25-50 nmole, n = 27) and/or 123I-Tyr-(A14)-insulin (100-150 MBq; 7.5-10 micrograms, n = 30).


RESULTS
HCC (1256 +/- 290 pmole bound/mg protein, Kd = 3.4 +/- 2.9 nM) expressed a 1000-fold higher number of specific receptors for 123I-Tyr-(A14)-insulin compared to normal liver tissue (2.4 +/- 0.8 pmole bound/mg protein, Kd = 4.2 +/- 2.4 nM), whereas HCC did not express receptors specific for 99mTc-NGA. All HCC lesions were identified as cold spots after injection of 99mTc-NGA, whereas 123I-Tyr-(A14)-insulin accumulated in these lesions, indicating HCC-to-normal liver ratios of 1.6 +/- 0.4 in the mean. Subtraction images obtained from planar studies visualized 123I-Tyr-(A14)-insulin in HCC lesions detected by 99mTc-NGA as cold spots.


CONCLUSIONS
This hepatocyte receptor-specific, double-tracer method using 99mTc-NGA and 123I-Tyr-(A14)-insulin could become clinically useful in the diagnosis of HCC.
Kurtaran
A
A
Department of Nuclear Medicine, University of Vienna, Austria.
Li
S R
SR
Raderer
M
M
Leimer
M
M
Müller
C
C
Pidlich
J
J
Neuhold
N
N
Hübsch
P
P
Angelberger
P
P
Scheithauer
W
W
D000368:Aged; D000418:Albumins; D037263:Asialoglycoprotein Receptor; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging*; D002352:Carrier Proteins / Q000032:analysis; D005260:Female; D006801:Humans; D007328:Insulin / Q000031:analogs & derivatives*; D007457:Iodine Radioisotopes; D008113:Liver Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D015609:Organotechnetium Compounds; D011877:Radionuclide Imaging; D011972:Receptor, Insulin / Q000032:analysis; D012680:Sensitivity and Specificity; D012709:Serum Albumin
D000418:Albumins; D037263:Asialoglycoprotein Receptor; D002352:Carrier Proteins; D007328:Insulin; D007457:Iodine Radioisotopes; D015609:Organotechnetium Compounds; D012709:Serum Albumin; C027122:hepatic sialoglycoprotein receptor; C036586:technetium Tc 99m neogalactoalbumin; C029491:insulin, 3-iodo-Tyr(A14)-; D011972:Receptor, Insulin