Radioimmunoscintigraphy of human malignant melanoma. I. Pharmacokinetics and localization of 125I-labeled monoclonal antibody RG-12 in thymectomized mice bearing renal melanoma xenotransplants

Neoplasma. 1989;36(5):505-11.

Abstract

The novel RG-12 monoclonal antibody (MoAb) recognizing a high-molecular-weight antigen of human melanoma cells was radioiodinated and its biodistribution and tumor imaging was determined in immunosuppressed mice bearing xenografted human malignant melanoma HMB-2. Control and tumor-bearing mice were injected with 6 micrograms of 125I-labeled RG-12 IgG (8.9 MBq 125I-IgG/animal). Clearance of the MoAb from plasma had a mean half life of 20.6 hours. At day 2 after injection, radiolabeled RG-12 IgG localized in the tumor was 1.43% of the injected dose bound per gram tissue (ID/g), whereas the localization in the healthy kidney was below 0.5%. Tumor to tissue ratio of MoAb accumulation was low for hepatic tissue (1.25) but high for spleen (3.30) and kidney (3.25), respectively. Scanning with a gamma camera localized tumor mass in the right kidney and implanted peritoneal metastases.

MeSH terms

  • Animals
  • Antibodies, Monoclonal* / pharmacokinetics
  • Cell Line
  • Half-Life
  • Humans
  • Immunoglobulin G* / pharmacokinetics
  • Iodine Radioisotopes*
  • Kidney Neoplasms / diagnostic imaging*
  • Kidney Neoplasms / immunology
  • Melanoma / diagnostic imaging*
  • Melanoma / immunology
  • Mice
  • Mice, Nude
  • Neoplasm Transplantation
  • Peritoneal Neoplasms / diagnostic imaging
  • Radionuclide Imaging
  • Tissue Distribution

Substances

  • Antibodies, Monoclonal
  • Immunoglobulin G
  • Iodine Radioisotopes