EFFECT OF THE ROUTE OF ADMINISTRATION ON THE BIODISTRIBUTION OF RADIOIODINATED OV-TL 3 F(AB')2 IN EXPERIMENTAL OVARIAN-CANCER

The effect of the route administration on the distribution of radioiod inated OV-TL 3 F(ab')(2) was studied in Balb/c female mice with intrap eritoneal or subcutaneous ovarian carcinoma xenografts. In the intrape ritoneal tumour model in which both ascites and solid tumour deposits were present, intraperitoneal administration resulted in a lower estim ated radiation dose to blood as compared with intravenous administrati on. In this model normalization to equal estimated radiation doses to blood for both routes of administration indicated that a twice as high estimated radiation dose can be guided to solid intraperitoneal tumou r deposits following intraperitoneal administration. Evacuation of asc itic tumour cells prior to monoclonal antibody injection further incre ased the estimated radiation dose to solid intraperitoneal tumour depo sits following intraperitoneal delivery. Following simultaneous intrav enous and intraperitoneal injection of the monoclonal antibody, tissue uptake showed no relevant differences in the subcutaneous tumour mode l. Overall, the intraperitoneal route of administration was found to b e the best choice for therapeutic delivery of iodine-131 labelled mono clonal antibodies.