• The Korean Journal of Nuclear Medicine
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• v.24 no.1
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• pp.29-36
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• 1990

Most of the diagnostic methods currently used for the detection of neoplastic masses provide indirect evidence. To obtain greater specificity in the interpretation of neoplasias by in vivo methods, the immunological approach appears to be most promising. Two problems that interfered with progress in this field were the lack of tumor specific antigen and the lack of well-defined and reproducible antibodies. To improve the sensitivity and specificity of radioimmunoscintigraphy as a technique for tumor localization, the use of monoclonal antibodies, fragments of antibodies and single photon emission computerized tomography (SPECT) are reasonable. The obvious advantages of monoclonal antibodies are their homogeneity, their specificity for the immunizing antigen and the reaction with a single determinant-thus no large immunecomplexes with antigen are formed. Monoclonal antibody technique has recently provided an opportunity to reevaluate the role of nuclear medicine for the diagnosis of malignant diseases by using the immunological approach. Out first results by means of radioimmunoscintigraphy of CEA and CA 19-9 producing tumors using a cocktail of fragments F $(ab')_2$, of mocolonal antibodies to CA 19-9 and CEA labeled with $^{131}I$ (IMACIS-1) are reported. The aims of this investigation was to evaluate the role of immunoscintigraphy in patients with colorectal and other cancers for diagnosis of local recurrences and metastasis. This report contains results of the first 8 colorectal and pancreas cancer patients with the elevation of the level of serum CEA and/or CA 19-9. IMACIS-1 was injected intravenously during 30 minutes in 100 ml saline solution after skin test. Planar scintigrams were recorded 3, 5 and 7 days after the injection of the IMACIS-1. Anterior, lateral and posterior views of the liver as well as anterior and posterior views of the pelvis were obtained in each patients as an $^{131}I-antibody$ image. We were able to localize exactly the malignant process with the double-nuclide double-compound $^{99m}Tc\;^{131}I$ (Tc+l) scintigrams. In Tc & I double-nuclide scintigraphy, computer subtraction display provided more clear localization of the tumor. We compared the results of radioimmunoscintigraphy with CT, ultrasonograms, conventional scintigrams. The results were as follows: 1) The sensitivity and specificity of radioimmunoscintigraphy using the fragments $F(ab')_2$ of the cocktails of CEA and CA 19-9 monoclonal antibodies were 80% and 100% respectively. 2) Tumor detection rate was not proportionated to the level of serum tumor markets. 3) Second tracer technique was essential for tumor localization as an anatomic landmark using double-nuclide scintigraphy. 4) A slow infusion of the antibodies was necessary to prevent the formation of large immune complexes. 5) Tumor/non-tumor radioactivity was most elevated at 7 days delayed imaging. 6) Using planar scintigraphic technique of $^{131}I$ labeled monoclonal antibodies are possible for imaging most of the tumors.

• The Korean Journal of Nuclear Medicine Technology
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• v.18 no.1
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• pp.149-152
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• 2014

Purpose: At our hospital blood is collected from a patient before an imaging test, with the concern of any effect possible when a nuclear medicine imaging test and an in-vitro test are carried out at the same time. However, occasionally, the blood collection is performed after an imaging test, with the reasons that the patient is not properly guided or the patient doesn't follow the guide correctly. In that case, we prefer to gather blood again after a few days. The purpose of this study is not only to see whether there is any effect of an imaging test on the result of the in-vitro test performed with the blood collected after the imaging test, but also to study how many days waiting after each test is appropriate to take a blood sample, if the effect exists. Materials and Methods: From September to October 2013, blood were collected from 13 patients in our hospital regardless of age and sex each time before and after the injection of the radioactive isotope from the tests : PET-CT, Gated Myocardial SPECT, and DTPA GFR Scan. Considering a half-life, AFP, CA19-9, CEA, TSH, and T3 were carried out right after the blood collection. In case of an iodine therapy, blood were taken each time before and after taking radioactive iodine, and, after AFP, CA19-9, and CEA, the difference between them in consistency and in cpm were compared. Results: With 10 patients after the imaging tests and 3 patients after the iodine therapy, their serum cpm was over 10,000. Over time, the cpm decreased in accordance with the half-life ($^{18}F$ 110minutes, $^{99}mTc$ 6hours, $^{201}Tl$ 72hours, $^{131}I$ 7days). Between the two cases, one before and the other after the injection of the radioactive isotope, the cpm and the results of AFP, CA19-9, CEA, TSH, and T3 from three patients each test, PET-CT, Gated Myocardial SPECT, and DTPA GFR Scan, were very similar. In addition, in case of an iodine therapy, there was also not a meaningful difference in the cpm and the results of AFP, CA19-9, and CEA, from three patients in an iodine therapy, between the two cases, one before and the other after taking the radioactive iodine. Conclusion: In case a blood collection was performed after the imaging test which required a radioactive isotope injection, the cpm increased, differently according to the kind of the radioactive isotope. However, the results of the in-vitro tests like AFP, CA19-9, CEA, TSH, T3, etc were nearly not affected. As the result, it's considered that there will not be any significant effect also from other tests, as the result from the performed seven tests.