The biological approach to radioimmunoscintigraphy

The authors have analysed the theoretical and clinical implications of a biological approach to radioimmunoscintigraphy (RIS), a new diagnostic technique based on the in vivo reaction between radiolabelled monoclonal antibodies and tumor-associated antigens expressed by the neoplastic cells. The assumption is that, as in all radioisotopic procedures, the radioimmunoscintigraphic image is the expression of differences in concentration (and not in density) between adjacent tissues. This "biological premise" is analysed to demonstrate a possible role of RIS not only in diagnosis but also in prognosis and therapy. A comparison with other imaging procedures and with histopathology, considered as the "gold standard" of the present-day morphological approach to diagnosis, is also discussed. Finally, biological premises, as well as the initial results and prospects regarding the use of high doses of radiolabelled monoclonal antibodies for therapeutic purposes are presented.