title: Estimates of radiation absorbed dose for intraperitoneally administered iodine-131 radiolabeled B72.3 monoclonal antibody in patients with peritoneal carcinomatoses.
abstract: Using a newly available model for determining estimates of radiation absorbed dose of radioisotopes administered intraperitoneally, we have calculated absorbed dose to tumor and normal tissues based on a surgically controlled study of radiolabeled antibody distribution. Ten patients with peritoneal carcinomatosis received intraperitoneal injections of the murine monoclonal antibody B72.3 radiolabeled with 131I. Biodistribution studies were performed using nuclear medicine methods until laparotomy at 4-14 days after injection. Surgical biopsies of normal tissues and tumor were obtained. The marrow was predicted to be the critical organ, with maximum tolerated dose [200 rad (2 Gy) to marrow] expected at about 200 mCi (7.4 GBq). In patients with large intraperitoneal tumor deposits, the tumor itself is an important source tissue for radiation exposure to normal tissues. Local "hot-spots" for tumor-absorbed dose were observed, with maximum tumor-absorbed dose calculated at 11,000 rad (11 Gy) per 100 mCi (3.7 GBq) administered intraperitoneal; however, tumor rad dose varied considerably. This may pose serious problems for curative therapy, especially in patients with large tumor burdens.
authors.affiliation: Nuclear Medicine Service, Sloan-Kettering Memorial Cancer Center, New York, New York 10021.
authors.forename: S M
authors.initials: SM
authors.lastname: Larson
authors.forename: J A
authors.initials: JA
authors.lastname: Carrasquillo
authors.forename: D C
authors.initials: DC
authors.lastname: Colcher
authors.forename: K
authors.initials: K
authors.lastname: Yokoyama
authors.forename: J C
authors.initials: JC
authors.lastname: Reynolds
authors.forename: S A
authors.initials: SA
authors.lastname: Bacharach
authors.forename: A
authors.initials: A
authors.lastname: Raubitchek
authors.forename: L
authors.initials: L
authors.lastname: Pace
authors.forename: R D
authors.initials: RD
authors.lastname: Finn
authors.forename: M
authors.initials: M
authors.lastname: Rotman
mesh_terms: D000042:Absorption; D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000276:immunology / Q000556:secondary*; D000293:Adolescent; D000328:Adult; D000911:Antibodies, Monoclonal / Q000008:administration & dosage; D000951:Antigens, Neoplasm / Q000276:immunology; D001063:Appendiceal Neoplasms / Q000000981:diagnostic imaging / Q000276:immunology; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging / Q000276:immunology; D006801:Humans; D007274:Injections, Intraperitoneal; D007457:Iodine Radioisotopes / Q000008:administration & dosage; D008875:Middle Aged; D010534:Peritoneal Neoplasms / Q000000981:diagnostic imaging / Q000276:immunology / Q000556:secondary*; D011829:Radiation Dosage; D011877:Radionuclide Imaging
chemical_list: D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm; D007457:Iodine Radioisotopes