Imaging of bone tumors using a monoclonal antibody raised against human osteosarcoma

The radiolabeled monoclonal antibody 791T/36 raised against a human osteosarcoma was injected into 20 patients with known or suspected bone tumors. Gamma camera images were acquired at 48 or 72 hours after injection, and assessed for antibody localization. Positive images were obtained in all five osteosarcomas and four other primary malignant sarcomas. Two of the four other primary bone tumors gave positive images. Three patients with trauma had negative images as did one patient with Paget's disease. Two patients with suppurative disease gave positive images. The antibody localized in the majority of malignant sarcomas tested. In one tumor where tissue was available, a tumor:non-tumor ratio of 2.8:1 was measured. Repeat imaging was performed in five patients. Immunoscintigraphy using the monoclonal antibody 791T/36 has shown tumor localization in patients with bone and soft tissue sarcomas.