RADIOIMMUNOIMAGING OF GLOMUS TYMPANICUM TUMORS BY IN-111 LABELED MONOCLONAL-ANTIBODY USING SINGLE-PHOTON EMISSION COMPUTED-TOMOGRAPHY

Objective: This study aimed to evaluate the diagnostic value of radioi mmunoimaging by radionuclide-labeled monoclonal antibody F023C5 (MAb), raised originally against carcinoembryonic antigen (CEA), in patients with glomus tympanicum tumors. Study Design: Prospective. Setting: Pr eoperative imaging versus radioactivity of removed tumor. Patients: Tw o patients with paraganglioma (glomus tympanicum). Intervention: Diagn ostic. Main Outcome Measure: Radiolabeled MAb accumulates in paragangl ioma tissue. Single photon emission computed tomography (SPECT) provid es improved detection of lesions. Results: SPECT using F023C5 MAb dete cted the abnormal accumulation of radioactivity in the middle ear regi on. This method detected paraganglioma less than 1 cm in diameter. Con clusions: Successful detection of glomus tympanicum in two patients us ing In-111-labeled F023C5 MAb is reported. The result suggests the rad ioimmunoimaging using this antibody is useful for the detection of not only primary glomus tumors, but also of local recurrence and unsuspec ted lesion in patients with paragangliomas.