Microdistribution of Thorotrast and dose to cellular structures

Hepatic and Perihepatic Involvement in Pneumokonioses and Other Mineral-Induced Diseases

“…It is estimated that the annual dose to the liver from a typical 25 ml of Thorotrast injection is 0.0025 Gy (Travis et al 1992). This is mainly due to the liver's high content in macrophages (Kupffer cells) capable of phagocytosing Thorotrast particles (Tessmer and Chang 1967;Wegener et al 1976;Kaul et al 1979;Irie and Mori 1987), where Thorotrast particles can also be detected by autoradiography (Yasumizu et al 1999) and by X-ray microanalysis (Terzaksi et al 1974;Odegaard et al 1978). In an assessment of the whole-body distribution of thorium and its daughters in a patient injected with Thorotrast 36 years prior to her death, approximately 45 % of all the activity was retained in the liver, and 3.5 % in a thorotrastoma (McInroy et al 1992).…”

“…The production of granuloma-like liver lesions caused by Thorotrast irradiation and containing epithelioid macrophages plus thorium dioxide granules was then reported in 1950 (Rotter 1950). The macrophages then congregate in the parenchyma and later in the portal tracts, forming aggregates of Thorotrast-laden cells (Kaul et al 1979;Irie et al 1986). Some of these aggregates have the features of so-called Thorotrast granuloma, a feature already published in 1950 (Rotter 1950;Polacarz et al 1992;Srinavasan and Dean 1997).…”

“…The stable deposition of macrophages with Thorotrast particles will lead to high-LET irradiation of the tissue compartment for long time periods. Alpha particles have a range of only up to 100 mm, resulting in local doses as much as 100 Gy/year at points 20 mm from a deposit of Thorotrast 5 mm in diameter (Kaul et al 1979;Dagle et al 1992). The radiation tracks can histologically be visualized by use of slide autoradiography and imaging plate autoradiography (Hassler et al 1964;da Silva Horta and Nunes 1973;Polacarz et al 1992;Goto et al 2002).…”

Delayed Effect of Thorotrast Deposition in Humans: Carcinogenesis and Suppression of the Reticuloendothelial System

“…Once thorotrast is infused into the blood, it is not eliminated easily from the body; over 90% of thorotrast forms deposits (6,15,30,32,55). After injection as a contrast material into the blood, it circulates to the systemic organs, soon accumulating in the liver, spleen and lymph nodes (8,18,29,32,56,57).…”