title: Radiotoxicity of h-R3 monoclonal antibody labeled with 188Re administered intracerebrally in rats.
abstract: Brain tumors are often incurable despite current aggressive treatment modalities. Regional intracerebral administration of labeled monoclonal antibodies (Mabs) can maximize the radioisotope and Mab concentration to tumor sites while reducing systemic toxicity. h-R3 is a humanized antiepidermal growth factor receptor Mab that successfully targets the epidermal growth factor receptor, which is overexpressed in glioblastomas. We studied the acute local and systemic toxicity effects of intraventricular 188Re-h-R3 in rats. Forty rats were distributed into four groups with five animals of each sex in each group. A single 5 -microl dose (2.5 microl into the left and 2.5 microl into the right lateral ventricles) of neutral solution containing 50 microg of h- R3 labeled with 49.5 +/- 1.7,284 +/- 13.7 or 579 +/- 23.7 muCi of 188Re were stereotactically administered to each animal. Control animals received vehicle alone. Each animal was observed twice daily for detection of toxicity signs. Body weights were recorded on days 0, 7 and 14. Blood samples for analysis of hematological and clinical chemistry parameters were taken on days 0 and 14. Necropsy and histopathological studies were carried out after completion of the study. All animals, but one, remained clinically stable. Toxicities included local radionecrosis, discrete increase in ALAT and creatinine blood values at higher dose level. We concluded that a single intraventricular administration of relatively large doses of 188Re-h-R3 is tolerable and causes minimal local and systemic toxicity effects in rats. Nevertheless, further studies are necessary to discard learning and behavioral problems.
authors: Centro Nacional para la Produccion de Animales de Laboratorio, Havana, Cuba.
authors: B
authors: B
authors: Gonzalez
authors: A
authors: A
authors: Casaco
authors: P
authors: P
authors: Alvarez
authors: M
authors: M
authors: Leon
authors: M
authors: M
authors: Arteaga
authors: A
authors: A
authors: Leon
authors: E
authors: E
authors: Santana
authors: A
authors: A
authors: Bada
authors: R
authors: R
authors: Figueredo
authors: R
authors: R
authors: Hernández
authors: N
authors: N
authors: Iznaga-Escobar
authors: F
authors: F
authors: González
authors: R
authors: R
authors: Perez
mesh_terms: D000230:Adenocarcinoma; D000818:Animals; D000911:Antibodies, Monoclonal / Q000008:administration & dosage / Q000633:toxicity*; D001835:Body Weight / Q000528:radiation effects; D001921:Brain / Q000473:pathology / Q000528:radiation effects; D019963:Clinical Chemistry Tests; D066246:ErbB Receptors / Q000276:immunology*; D005260:Female; D006403:Hematologic Tests; D006801:Humans; D007276:Injections, Intraventricular; D008175:Lung Neoplasms; D008297:Male; D009336:Necrosis; D009929:Organ Size / Q000528:radiation effects; D011833:Radiation Injuries, Experimental; D011868:Radioisotopes; D019275:Radiopharmaceuticals / Q000008:administration & dosage / Q000633:toxicity*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012211:Rhenium; D013238:Stereotaxic Techniques; D018675:Toxicity Tests; D014407:Tumor Cells, Cultured
chemical_list: D000911:Antibodies, Monoclonal; D011868:Radioisotopes; D019275:Radiopharmaceuticals; D012211:Rhenium; D066246:ErbB Receptors