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The Spread of Chest Tumours to the Abdomen, and some Abdominal Tumours to the Chest - also a consideration of some relevant abdominal conditions in differential diagnosis, particularly of the Liver, Spleen and Pancreas.
Published in Fred W Wright, Radiology of the Chest and Related Conditions, 2022
Historical. In the 1950s, when most liver disease was unrecognisable radiologically, all one could do was to recognise a large liver, (palpate its edge, note pulsation with severe tricuspid incompetence), or occasionally note intra-hepatic calcification. Lumsden and Truelove (1957) in Oxford were able to visualise the surface of the liver and note masses deforming its surface following an induced pneumoperitoneum (mostly with CO2). Coeliac and hepatic angiography also showed some tumour masses (or a cirrhotic pattern) due to their abnormal circulation. Thorotrast (also used for angiography in the 1930s and 1940s - see Illus. THOROTRAST) was taken up in the reticulo-endothelial cells of the liver and spleen, and could be used to image the liver particularly with tomography, demonstrating large secondary deposits as negative defects. (Its long half-life of 1.4 x 10^0 years jn those who had gross metastatic disease, and the possibility of inducing tumours of the spleen and liver 20 or more years later was irrelevant). Hepatography using emulsified Lipiodol (injected into the portal venous system, via the unobliterated umbilical vein, usually found in the upper part of the umbilicus under local anaesthesia) was used in the 1960s, particularly in France; an advantage was that, as with lymphography, the liver remained opacified for up to 18 months. It is being used again now for CT enhancement of the liver (see references).
Radiation Hormesis in Cancer
Published in T. D. Luckey, Radiation Hormesis, 2020
Cancer risks from thorium are often calculated with a linear model from excess cancers following Thorotrast injections. This procedure is not applicable to the general population for several reasons.57 Thorotrast was administered only to people with suspected disease. Effects from the very poor absorption of thorium salts do not remotely resemble effects following ThO2 injection. Incomplete epidemiologic followup after therapeutic doses have little or no value in evaluation of risks for near ambient levels of radionuclides because high and low doses give opposite results.57
Special Problems of Internal Radioactive Materials
Published in George W. Casarett, Radiation Histopathology, 2019
Thorium-232 is an alpha emitter with a physical half-life of 1.39 × 1010 years. After its introduction in 1928, thorotrast, a 20% colloidal suspension of thorium dioxide, became widely used as a contrast medium in diagnostic radiology. Amounts of 3 to 15 grams were administered intravenously. The colloidal particles are rapidly phagocytosed and concentrated in cells of the reticuloendothelial system. Looney76 found that the excretion of thorium dioxide is minimal. He estimated the biological half-life to be about 190 years. The colloid tends to remain fixed in the tissues, although there is some migration which is probably accomplished within the macrophages which are migrating.
Mesothelioma mortality within two radiation monitored occupational cohorts
Published in International Journal of Radiation Biology, 2022
Michael T. Mumma, Jennifer L. Sirko, John D. Boice, William J. Blot
Radiation. Therapeutic doses of radiation and injection with Thorotrast, an alpha-particle emitting colloidal solution of thorium dioxide used as a diagnostic radiographic contrast medium, are likely causes of mesothelioma, including cancers of the pleura and peritoneum. However, cancer of the pleura is not increased among atomic bomb survivors, and large-scale studies of occupational groups exposed to low radiation levels are either negative or the increases are attributed to asbestos exposure. Associations between radiation and asbestosis (which is only caused by asbestos) indicate that jobs with relatively high radiation exposures are highly correlated with jobs with relatively high asbestos exposure. Over 83,000 IRs not employed at shipyards did not have an excess of mesothelioma or asbestosis, and there was no clear evidence of a radiation dose-response relationship in the overall cohort. Low-dose radiation received in these occupational setting was not found to be associated with mesothelioma.
All for one, though not one for all: team players in normal tissue radiobiology
Published in International Journal of Radiation Biology, 2022
Marjan Boerma, Catherine M. Davis, Isabel L. Jackson, Dörthe Schaue, Jacqueline P. Williams
The study of normal tissue reactions has been a subfield of radiation biology almost since the discovery of X-rays; the need to understand the impact of radiation exposure, whether beneficial or detrimental, on biological tissues was quickly recognized. Indeed, even as radiation was being developed as both a diagnostic tool and therapeutic application, its potential to induce injury in non-targeted tissues and organs, particularly in the skin, was quickly recognized (Johnston et al. 2010; Timins 2011). Interestingly, although ionizing radiation was identified as an environmental mutagen as early as the 1920s (Muller 1927), it was decades later before studies of workers, such as the radium dial painters (Sherk 2001) and uranium miners, (McLaughlin 2012) etc., and even some patient populations, such as those receiving Thorotrast®, etc. (Lipshutz et al. 2002) led to broad acknowledgement of its carcinogenic risk. Observations of leukemia in the survivors of the Japanese atomic bombs (Folley et al. 1952) and later reports of increased incidence of not only hematologic, but also solid tumors, following analyses of the Life Span Study (Hsu et al. 2013; Grant et al. 2017) left no further doubt. Ultimately, radiation-induced acute and late normal tissue effects, whether cancer or non-cancer, have been recognized as occurring in every tissue and organ, imposing limits on the use of radiation as a therapeutic modality.
Radiation databases and archives – examples and comparisons
Published in International Journal of Radiation Biology, 2019
Alia Zander, Tatjana Paunesku, Gayle Woloschak
Thorium-based radioactive contrast agent was used worldwide from 1929 to the 1950s for imaging the liver, spleen, and blood vessels. Because of its long half-life, patients were exposed to internal ionizing radiation throughout their entire lives. To determine the health effects of this internal exposure, many countries, including Germany, Japan, Denmark, Sweden, the United States, and Portugal created retrospective cohort studies. Germany’s cohort study was the largest and had the longest follow-up time. They initiated the study in 1968 with 2,326 Thorotrast treated patients and 1,890 matched control patients. Medical files were researched for patients that died before 1968 and all living patients were examined biannually until death (Grosche et al. 2016). The follow-up period lasted until 2004 and results showed that compared to the general population, the exposed cohort showed a significant increase in mortality due to malignant tumors and diseases of the circulatory and digestives systems, while the unexposed control group did not (Becker et al. 2008). During the same time period, there were multiple controlled animal studies investigating the role of thorium in rats. In one study, 540 female Wistar rats were divided into six groups that showed that the interaction between Thorotrast and quartz created a synergistic effect to increase lung carcinogenesis incidence and decrease time to onset (Spiethoff et al. 1992). All of the German Thorotrast data can be found through the European Radiobiology Archives (ERA) (Birschwilks et al. 2011; Birschwilks et al. 2012; European Radiobiology Archives 2017), described in a separate section below, and the STORE database, which is a data repository for international radiobiology data and resources (STORE database. 2016). Most of the animal data is publicly available, while some animal data and all human data requires approval.