RADIOIMMUNODETECTION OF HUMAN SMALL-CELL LUNG-CARCINOMA XENOGRAFTS INTHE NUDE RAT USING IN-111 LABELED MONOCLONAL-ANTIBODY MOC-31

The applicability of mouse monoclonal antibody MOC-31 for in vivo radi oimmunodetection of human small cell lung cancer (SCLC) was investigat ed in a nude rat xenograft model. MOC-31 is reactive with a 38 kD pan- carcinoma membrane antigen. [In-111]DTPA-MOC-31 showed good in vivo im munolocalisation to xenografted SCLC cells, whereas antigen-related up take was low in normal rat tissues and in a control antigen-negative, human-derived tumour. Non-antigen-related uptake in the liver could be blocked by pretreatment with irrelevant antibody. It is concluded tha t MOC-31 can be used for radioimmunodetection of SCLC in vivo and may be suitable as a targeting device in patients.