title: Experimental induction of bone tumors by short-lived bone-seeking radionuclides.
abstract: Single and repeated applications of 224Ra and single applications of 227Th to more than 600 female NMRI mice 3 - 4 weeks old, and to male NMRI mice have led to a high rate of osteosarcomas. Tumor incidence is dose-related. 227Th is more carcinogenic than 224Ra which induced the highest tumor incidence of 60% after a single injection of 5 muCi per Kg body weight or more. Repeated injections of 224Ra to female mice yielded a tumor incidence of up to 92%. Most of these osteosarcomas consist of well-differentiated bone-forming osteoplastic tissue. Half of the tumors occurred in the spine, particularly in the lumbar region. In protraction experiments, multifocal osteosarcomas have been observed. Less than 10% of the mice with osteosarcoma had developed metastases in lung, spleen, liver, and kidney. The possible mechanisms of the protraction effect are discussed.
mesh_terms: D000818:Animals; D001848:Bone Diseases, Developmental / Q000209:etiology / Q000473:pathology; D001859:Bone Neoplasms / Q000209:etiology* / Q000473:pathology; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006207:Half-Life; D008297:Male; D051379:Mice; D009374:Neoplasms, Experimental / Q000209:etiology / Q000473:pathology; D009378:Neoplasms, Multiple Primary / Q000209:etiology; D009381:Neoplasms, Radiation-Induced / Q000473:pathology*; D012516:Osteosarcoma / Q000209:etiology* / Q000473:pathology; D011883:Radium / Q000008:administration & dosage / Q000009:adverse effects*; D012888:Skull Neoplasms / Q000209:etiology; D013125:Spinal Neoplasms / Q000209:etiology; D013910:Thorium / Q000008:administration & dosage / Q000009:adverse effects*; D013997:Time Factors
chemical_list: D013910:Thorium; D011883:Radium