Extent of Nonspecific Background Localization of Radioiodinated Serum Proteins in Human Tumor and Normal Tissues

Abstract

The 24-hour uptake of intravenously injected, radioiodinated, rabbit- and human-serum globulins and human-serum albumin, in a variety of human tumor and normal tissues, was measured after surgical excision. No detectable difference between the uptake by tumor and normal tissue was found. An average background localization value of 0.004 percent (normalized to a 50-kg. patient) of the injected radioactive dose per gm. of wet, unperfused tissue was obtained. It was concluded that in any future assays of whole radioiodinated antitumor antiserum globulin, tumor-localizing antibodies of average titer, if and when obtained, should be detectable in human tumors, above and beyond the nonspecific background localization of radioiodinated serum proteins, without purification and concentration.