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PubMed1978

[Determination of thorotrast amount deposited in patients (author's transl)].

Thorotrast amount deposited in patients, chiefly in the liver and the spleen, was determined with a NaI detector and a Computerised Axial Tomography (CT). In the measurement of the gamma-rays with the NaI detector, the geometry-factors, that are the distance from the detector to the source, the attenuation of the gamma-rays in the tissue and the shapes of the liver and the spleen, were studied, and the mean amount deposited in the organs was determined. In the measurement with CT, the relationship of CT-Number and the amount of thorium was got, and the localized amount and the distribution in the organ were measured.

Gamma Rays↗
PubMed1976

Vinyl chloride-associated liver disease.

Although polyvinyl chloride has been produced from vinyl chlride monomer for more than 40 years, recognition of toxicity among vinyl chloride polymerization workers is more recent. In the mid 1960s, workers involved in cleaning polymerization tanks were found to have acro-osteolysis. In 1974, the same population of workers was found to be at risk for an unusual type of hepatic fibrosis and angiosarcoma of the liver. We describe two cases of vinyl chloride-associated liver injury, one of hepatic fibrosis and one of angiosarcoma. Histologic features of these lesions are similar to the hepatic fibrosis and angiosarcomas resulting from chronic exposure to inorganic arsenicals. Preliminary studies suggest that the toxicity of vinyl chloride may result from formation, during high-dose exposure, of active metabolites by mixed function oxidases of the liver. Epidemiologic studies indicate an increased incidence not only of liver disease, but also of cancers of the brain, lung, and possibly other organs.

Adult↗
PubMed1989

Long-term tissue distribution and steady state activity ratios of 232Th and its daughters in rats after intravascular injection of Thorotrast.

To estimate the absorbed dose in the critical organs of Thorotrast patients, it is necessary to know not only the distribution and concentration of 232Th but also its daughter nuclides in the body. The present investigation was undertaken in order to clarify the long-term 232Th tissue distribution and steady state activity ratios between subsequent daughters in the critical tissues using about 30 Wister male rats, as a basis for estimating absorbed doses. The tissue distribution of thorium was examined by means of an autoradiography of the whole body and/or the gamma-ray spectrometry at various times during 2 to 24 months following injection. The concentrations of daughter nuclides in tissues were determined by repetitive gamma examination over a period from 1 hr to 35 days after being sacrificed. The data indicate (1) that approximately 90% of injected Thorotrast is retained in the body for a prolonged period, but about 50% of radium and 10% of radon produced from thorium are eliminated from the body, (2) that the mean steady state activity ratios of 224Ra and 212Pb to 228Th for liver are 0.56 and 0.28, and 0.54 and 0.16 for spleen, 0.58 and 0.82 for lungs, respectively, and (3) that the parent 228Th is translocated to the bone.

Animals↗
PubMed1999

Mortality after long-term exposure to radioactive Thorotrast: a forty-year follow-up survey in Sweden.

To evaluate temporal patterns of cause-specific mortality after long-term exposure to the alpha-particle-emitting contrast medium Thorotrast, we investigated a cohort consisting of 693 Swedish patients with neurological disorders who received Thorotrast during cerebral angiography, with follow-up ending in 1993. Standardized mortality ratios (SMRs) were calculated as the ratio of observed cases in the cohort to expected cases in the general population. Persons exposed to Thorotrast had significant excesses of all causes of death (SMR = 2.8; 95% CI 2.5-3.0), with similar increases noted for men and women. The largest risks were observed for deaths from hematological causes (SMR = 16.4; n = 8), cerebrovascular diseases (SMR = 10.1; n = 18), gastrointestinal disorders including liver cirrhosis (SMR = 5.2; n = 36), and tumors (SMR = 4.7; n = 187). There was a significant decrease in SMR with time since injection for cerebrovascular and circulatory diseases, indicative of the impact of underlying neurological disorders. In contrast, the SMR increased significantly with time for tumors and gastrointestinal diseases, suggestive of a detrimental effect of cumulative radiation dose. A significant dose-response relationship was found for all causes of death and malignant tumors among all age groups, and since SMR increased with time for the latter category, this is consistent with an effect of cumulative radiation exposure on cancer development. However, the findings should be treated with caution, since selection bias may have influenced some of the results.

Aged↗
PubMed1999

The german thorotrast study: recent results and assessment of risks.

The German Thorotrast study comprises 2,326 patients and 1,890 controls. Forty-eight Thorotrast patients and 239 controls are still alive and are invited for a follow-up examination every 2 years. In the deceased patients, the following neoplastic diseases with excess rates were registered (Thorotrast/controls): liver cancer (454/3); cancer of the bile ducts, including gallbladder (42/7); myeloid leukemia (40/7); myelodysplastic syndrome (30/4); plasmacytoma (10/2); non-Hodgkin's lymphoma (15/5); bone sarcoma (4/1); malignant peritoneal or pleural mesothelioma (9/0). Dose calculations are based on results of whole-body counting, X-ray films, and data obtained from the hospital records on the volume of Thorotrast injected. For liver cancer, the cumulative risk estimate was calculated to be 40 per 10(4) person Sv (radiation weighting factor = 20). These figures are close to the results of the Danish study and are comparable to the results of the Life Span Study of A-bomb survivors after 40 years at risk with 18 to 48 liver cancers per 10(4) person Sv. For hematopoietic malignancies, the cumulative risk was calculated to be about 7 per 10(4) person Sv (radiation weighting factor = 20). This risk estimate is lower by a factor of 10 compared to the results of the Life Span Study.

Adult↗
PubMed1999

1998 results of the first series of follow-up studies on Japanese thorotrast patients and their relationships to an autopsy series.

The 1998 survey of the first series of epidemiological studies of Japanese Thorotrast patients revealed that 18 (6.9%) were alive and 244 (93.1%) had died among 262 war-wounded veterans to whom Thorotrast had been administered intravascularly. Of 1,630 age- and sex-matched controls, 525 (32.2%) were alive and 1,105 (67.8%) had died. These results indicated a shortening of the life span in patients who had received Thorotrast compared to their controls. Of the patients in the Thorotrast group, the main causes of death were liver malignancies (79, 30.2%), liver cirrhosis (20, 7.6%), blood diseases (9, 3.4%), and cancers of the extrahepatic bile duct (5, 1.9%). Statistical analyses by the chi(2) test and estimation of the relative risk (risk ratio) showed that the incidences of these disorders were significantly higher in the Thorotrast group than in the controls. In the 54-year period from 1945 to 1998, our autopsy series was enlarged to include 398 individuals: 386 injected with Thorotrast intravascularly and 12 injected by other routes. Results of analyses of the 386 autopsy cases given Thorotrast intravascularly were as follows: 263 cases (68.1%) of liver malignancies, 28 cases (7.3%) of liver cirrhosis, 29 cases (7.5%) of blood diseases, 16 cases (4.1%) of lung cancer, 4 cases (1.0%) of malignant peritoneal tumors, 2 cases (0.5%) of bone sarcomas, and 1 case (0.3%) of hemangiosarcoma of the spleen. The relative risks of liver malignancies, blood diseases, bone sarcomas, malignant peritoneal tumors, and hemangiosarcoma of the spleen manifested significantly higher ratios in the Thorotrast autopsy cases (ratio of proportion) than in the autopsy control cases. Histological studies of these autopsied cases revealed that Thorotrast-induced liver malignancies showed remarkable differences in the proportions of histological types of tumors from those of non-Thorotrast liver malignancies since 1975. However, in this survey, we noted a remarkable increase in the incidence of liver malignancy of multiple histological types compared to that in histological controls. Based on the results of our 1998 survey, we estimated attributable risks of Thorotrast-inducedliver malignancies and blood diseases in the life span. Results showed 523 liver malignancies per 10(4) person Gy and 150 blood diseases per 10(4) person Gy for Japanese male Thorotrast carriers (wasted dose 10 years).

Adolescent↗