Assuntos
Neoplasias Ósseas/genética , Neoplasias Ósseas/patologia , Mutação/genética , Mutação/efeitos da radiação , Plutônio/toxicidade , Rádio (Elemento)/toxicidade , Estrôncio/toxicidade , Animais , Cães , Humanos , Modelos Biológicos , Osteossarcoma/genética , Osteossarcoma/patologia , Reprodutibilidade dos TestesRESUMO
The severity of effect as a function of skeletal radiation dose for induced skeletal malignancy was investigated among a relatively large group of beagle dogs singly injected as young adults with soluble radionuclide. Bone-seeking radionuclides considered were 239Pu, 226Ra, 228Ra, 224Ra, 228Th, and 90Sr. Variables included skeletal radiation dose, tumor growth rate, maximum tumor volume, sex of the animals, growth period of the tumor, degree of calcification of the tumor, skeletal location of the tumor, year of death, and occurrence of metastases. Except for a significant relationship between tumor volume and metastatic process and for growth rate and tumor volume, no significant dependence of any two of these factors could be established. It is concluded from available data on skeletal malignancies among beagles exposed to bone-seeking radionuclides that the severity of the disease is not dependent upon skeletal radiation dose.
Assuntos
Neoplasias Ósseas/diagnóstico , Neoplasias Ósseas/etiologia , Relação Dose-Resposta à Radiação , Neoplasias Induzidas por Radiação/diagnóstico , Neoplasias Induzidas por Radiação/etiologia , Radioisótopos/efeitos adversos , Medição de Risco/métodos , Animais , Neoplasias Ósseas/classificação , Cães , Neoplasias Induzidas por Radiação/classificação , Doses de Radiação , Fatores de Risco , Índice de Gravidade de Doença , Análise de SobrevidaRESUMO
Neither Fisher's Exact Test nor linear regression analysis (dose-response relationship) using average skeletal dose from 239Pu as a surrogate for marrow dose could establish a statistically significant association between malignant hematopoietic disease (MHD including leukemia and aleukemia) and exposure to 239Pu among dogs in the Utah beagle colony. In addition, when dog-years at risk was the parameter used to estimate the rate of expected malignant hematopoietic tumors in dogs exposed to 239Pu, the estimate was within the range of the 95% confidence limits of the control dogs for six cases (and also within the 95% confidence limits for five cases when the single case of lymphoma was omitted). It was concluded that if there was an effect of 239Pu exposure on the occurrence of MHD in this beagle experiment, it was not very meaningful. These data could not establish a significant susceptibility to neoplasia of either myeloid or lymphoid tissue of 239Pu exposure.
Assuntos
Neoplasias Hematológicas/epidemiologia , Leucemia Induzida por Radiação/epidemiologia , Modelos Biológicos , Plutônio/administração & dosagem , Plutônio/análise , Radiometria/métodos , Medição de Risco/métodos , Distribuição por Idade , Animais , Carga Corporal (Radioterapia) , Modelos Animais de Doenças , Cães , Feminino , Incidência , Injeções , Masculino , Doses de Radiação , Valores de Referência , Análise de Sobrevida , Taxa de SobrevidaRESUMO
No significant differences in lifespan could be established between control dogs and dogs given 241Am, 228Th, 90Sr, 228Ra, 226Ra or monomeric 239Pu at low dosage levels that induced less than 10% skeletal malignancies (low dose animals) in the Utah beagle colony when all dogs surviving at least 1 y were included in the analysis and dogs given individual radionuclides were considered separately or together. Censoring or exclusion of dogs from these groups that were diagnosed with skeletal malignancies or that died in a gran mal epileptic seizure made no important difference to these results. Therefore, an enhanced lifespan of low dose dogs as compared with controls could not be established. It is concluded that low doses from internal (mainly skeletal) deposits of these radionuclides probably do not benefit the survival of individuals so exposed.
Assuntos
Neoplasias Ósseas/mortalidade , Longevidade/efeitos da radiação , Modelos Biológicos , Neoplasias Induzidas por Radiação/mortalidade , Radioisótopos/administração & dosagem , Radioisótopos/análise , Radiometria/métodos , Medição de Risco/métodos , Animais , Carga Corporal (Radioterapia) , Modelos Animais de Doenças , Cães , Relação Dose-Resposta à Radiação , Feminino , Injeções , Masculino , Modelos de Riscos Proporcionais , Doses de Radiação , Valores de Referência , Distribuição por Sexo , Análise de Sobrevida , Taxa de SobrevidaRESUMO
Data in the archives of the beagle project at the University of Utah were used to determine whether there might have been an association between the occurrence of soft tissue cancer and bone tumor (skeletal malignancy) among the dogs injected with bone-seeking radionuclides. In addition to comparing the numbers of animals with and without bone tumors and with and without soft tissue cancers, data on bone sarcomas and soft tissue sarcomas were compared. Longevity (postinjection survival) of the dogs was investigated. It appeared that survival (time between radionuclide injection and death) was important in the eventual expression of malignancies. There could not be established a possible susceptibility to skeletal malignancy associated with the occurrence of soft tissue cancer (or soft tissue sarcoma). We concluded that, although the literature reports an increased susceptibility for subsequent malignancies for individuals with naturally-occurring or radiation-induced cancer, the data derived from this study do not confirm the concept that the appearance of soft tissue cancer is strongly associated with an increased risk of developing a radionuclide-induced skeletal malignancy.
