CaNa(2)EDTA for improvement of radioimmunodetection and radioimmunotherapywith In-111 and Y-90-DTPA-anti-CEA MAbs in nude mice bearing human colorectal cancer
N. Watanabe et al., CaNa(2)EDTA for improvement of radioimmunodetection and radioimmunotherapywith In-111 and Y-90-DTPA-anti-CEA MAbs in nude mice bearing human colorectal cancer, J NUCL MED, 41(2), 2000, pp. 337-344
Citations number
33
Categorie Soggetti
Radiology ,Nuclear Medicine & Imaging","Medical Research Diagnosis & Treatment
In-111 and Y-90, dissociated from In-111-labeled-monoclonal antibody (MAb)
and Y-90-labeled MAb, may cause deterioration of the image quality in radio
immunodetection (RID) and undesirable irradiation of nontargeted tissue in
radioimmunotherapy (RIT), respectively. The aim of this study was to invest
igate any improvement in RID and RIT with (111)ln-MAb and Y-90-MAb by pre-
and postadministration of calcium disodium ethylenetriaminetetraacetic acid
(CaNa(2)EDTA). Methods: Murine MAb F33-104 against carcinoembryonic antige
n (CEA) was labeled with In-111 or Y-90 by the diethylenetriamine pentaacet
ic (DTPA)-anhydride method. The influence of CaNa(2)EDTA on loss of radioac
tivity from In-111-MAb or Y-90-MAb in serum was investigated in vitro. The
effects of CaNa(2)EDTA, administered before and after In-111-MAb or Y-90-MA
b, on the biodistribution or radioactive isotopes in nude mice bearing huma
n colon adenocarcinoma LS 180 tumor expressing CEA, or human pulmonary carc
inoma PC 9 tumor expressing no CEA, were then examined. As a control, 0.9%
NaCl was used in both the in vitro and in vivo studies. Results: CaNa(2)EDT
A did not cause any decrease in levels of radioactivity of radiolabeled MAb
s. Pre- and post-treatment with CaNa(2)EDTA reduced radioctivity in both sp
ecific and nonspecific tumors at 72 h after In-111-MAb injection resulting
in an increase of the specific tumor-to-nonspecific tumor radioactivity rat
io. The levels of hepatic and renal radioactivity were also subsequently de
creased by CaNa(2)EDTA. On the other hand, CaNa(2)EDTA pre- and post-treatm
ent reduced levels of bony, hepatic, and renal radioactivity at 24, 72, and
72 h, respectively, after Y-90-MAb injection, although it had no effect on
tumor radioactivity, Conclusion: Pre- and post-treatment with CaNa(2)EDTA
would be of great use in humans who undergo RID or RIT with In-111-MAb and
Y-90-MAb accompanied by disassociation of the labeled radionuclides.