INDIUM-111-LABELED ANTI-EGFR-425 SCINTIGRAPHY IN THE DETECTION OF MALIGNANT GLIOMAS

Background. The monoclonal antibody anti-epidermal growth factor recep tor (EGFr)antibody-425, against the epidermal growth factor receptor, has the potential to bind specifically to gliomas and not normal brain tissue.(1-3) A prospective study was conducted (1986-1988) to evaluat e the use of Indium-111 (In-111)-labeled anti-EGFr-425 in the localiza tion of gliomas before radioimmunotherapy with Iodine-125 (I-125)-labe led anti-EGFr-425. Methods. Twenty-eight patients with intracranial ne oplasms were injected intravenously with an average dose of 2.2 mCi In -111-labeled anti-EGFr-425. Planar and single-photon emission computed tomography scans were performed after 48 and 72 hours. Control studie s also were performed in two cases with In-111-labeled Co 17-1A (an an tibody to colorectal cancer) and in one case with unlabeled In-111 chl oride. Results. The immunoscintigraphic findings were generally in goo d agreement with computerized tomographic findings. The definitive dia gnosis was established by biopsy findings: 23 gliomas (1 Grade I, 5 Gr ade II, 6 Grade III, and 11 Grade IV), 1 meningioma, and 4 metastatic lesions. The localization of gliomas with In-111-labeled anti-EGF-425 had a sensitivity of 0.96, a specificity of 0.60 and an accuracy of 0. 90. Conclusion. Immunoscintigraphy with (111)-In labeled anti-EGFr-425 can be useful in the management of malignant gliomas, especially befo re radioimmunotherapy with I-125-labeled anti-EGFr-425.