In ovarian cancer, traditional radiologic methods lack sensitivity and are not sufficiently specific to diagnose early and recurrent ovarian cancer. So most of the patients have been diagnosed in advance disease state. Thus, there is a need for
an
accurate, noninvasive diagnostic test. The newly developed monoclonal antibody(Mab) desinated 145-9 recognized CA 125 antigens more accurately to different epitope than recognized by traditional OC125 antibody. This is clinical study assessing
the
safety, kinetics and imaging sensitivity of Mab 145-9. Two milligrams of Mab were labeled with 111 MBq(3.0 mCi) of 131I and infused intravenously in 28 patients with ovarian carcinoma. Radiommunoscintigraphies were done at third, fifth and
seventh
day.
The 131I-labeled antibody was tested for pyrogenecity and sterility (bacteria, mycoplasma and viral culture) ; all tests were negative. The range of immunoreactivity was between 52% and 72%. No adverse reactions and change in vital sign were
seen.
Pharmacokinetic studies showed the steady state volume of distribution (Vdss) to be 2,772±466ml(Mean±S.D), and clearance 51.3±12.7ml/hr. All immunoscintigraphy were considered positive in ovarian cancer. Immunoscintigrapy detected tumor
lesions
were
confirmed in operative fields, in two patients with normal serum levels of CA125 and in seven patients whose radiologic findings (CT, MRI or USG) showed negatlve findings. Furthermore no malignant tumor lesions were found in operative fields, in
4
patients with negative immunoscinitigrafic findings. But the image was not precise than CT or MRI. In summary, radiolmmunoscintigraphies using 131I-labeled Mab 145-9 were done safely in ovarian cancer, and this preliminary results reveal a high
sensitivity compared to traditional radiological methods for the early diagnosis of primary and recurrent ovarian cancer. But further randomized study may be necessary to obtain more precise and specific image and to use in clinical fields.
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