Author |
장대환(Dae Hwan Jang),최덕주(Duck Joo Choi),이범우(Bum Woo Lee),박원(Won Park),한창순(Chang Soon Han),김학산(Hak San Kim),김종순(Chong Soon Kim), |
Abstract |
The cocktails of two 131I labeled Monoclonal antibody
(MCAB) (Anti CA 19-9 F(ab')2+Anti CEA F(ab')2
fragment), which react specially, with human
gastrointestinal cancers, were administered to 10
patients with colorectal (7), stomach (2) and pancreas
(l) cancer for scintigraphic detection. All patients
were known or postoperatively recurrent cases, and
serum tumor markers, CA 19-9 and CEA, were measured
with immunoradiometric assay, just before
immunoscintigraphy (ISG). The tumor marker's level in
serum is not correlated with positive tumor uptake in
ISG. The sensitivity and specificity of ISG in
detection of 21 tumor sites, based on surgery, CT,
ultrasonography and pathology, were 90.5% and 100%. One
case of colon cancer showed gall bladder metastasis,
which was neglected on CT study. Tumor/non tumor uptake
ratio of radiolabelled antibody were progressively
increased from day 3 to day 7 during study. We
summerized as follows: 1) The use of cocktails of CEA
and CA 19-9 MCAB F(ab')2 increased sensitivity and
specificity in ISG. 2) Delayed imaging (later than 5
days) increases sensitivity and specificity due to
exclusion of nonspecific iodine accumulation in stomach
and lung. 3) Second tracer technique is essential for
anatomical landmark by use of a double isotope scan,
but subtraction technique, a possible source of
artifacts, is no longer necessory when delayed imaging
is performed. 4) It may be possible to use two MCAB
cocktails of CA 19-9 and CEA in Radioimmunodetection of
stomach and pancreas cancer. In conclusion, ISG using
MCAB cocktails, F(ab')2 fragment of anti CA 19-9 and
Anti CEA, provide additional opportunity for tumor
localization and detection of colorectal and other G-I
cancer, such as stomach and pancreas. |