In cooperation with the Department of Nuclear Medicine, and the Laboratory of Tumor Immunology and Biology, we have initiated clinical trials for the treatment of peritoneal carcinomatosis. A classical phase one study has begun using escalating doses of I-131 labeled antibody administered intraperitoneally. Dose limiting toxicity appears still to be bone marrow, with patients with extensive previous chemotherapy being limited to 125-150 mCi. Patients without extensive pretreatment may be able to receive as high as 175 Mci, although this dose level has not been reached yet. The clinical protocol has been recently revised by Dr. Carrasquillo to more accurately define the maximum tolerated doses. A follow-up protocol using a higher affinity antibody CC49, with Lu-177 for isotope is being written in conjunction with the Medicine Department.