Thorotrast

Jump to: navigation, search

WikiDoc Resources for Thorotrast

Articles

Most recent articles on Thorotrast

Most cited articles on Thorotrast

Review articles on Thorotrast

Articles on Thorotrast in N Eng J Med, Lancet, BMJ

Media

Powerpoint slides on Thorotrast

Images of Thorotrast

Photos of Thorotrast

Podcasts & MP3s on Thorotrast

Videos on Thorotrast

Evidence Based Medicine

Cochrane Collaboration on Thorotrast

Bandolier on Thorotrast

TRIP on Thorotrast

Clinical Trials

Ongoing Trials on Thorotrast at Clinical Trials.gov

Trial results on Thorotrast

Clinical Trials on Thorotrast at Google

Guidelines / Policies / Govt

US National Guidelines Clearinghouse on Thorotrast

NICE Guidance on Thorotrast

NHS PRODIGY Guidance

FDA on Thorotrast

CDC on Thorotrast

Books

Books on Thorotrast

News

Thorotrast in the news

Be alerted to news on Thorotrast

News trends on Thorotrast

Commentary

Blogs on Thorotrast

Definitions

Definitions of Thorotrast

Patient Resources / Community

Patient resources on Thorotrast

Discussion groups on Thorotrast

Patient Handouts on Thorotrast

Directions to Hospitals Treating Thorotrast

Risk calculators and risk factors for Thorotrast

Healthcare Provider Resources

Symptoms of Thorotrast

Causes & Risk Factors for Thorotrast

Diagnostic studies for Thorotrast

Treatment of Thorotrast

Continuing Medical Education (CME)

CME Programs on Thorotrast

International

Thorotrast en Espanol

Thorotrast en Francais

Business

Thorotrast in the Marketplace

Patents on Thorotrast

Experimental / Informatics

List of terms related to Thorotrast


Overview

File:Thorotrast.jpg
Thorotrast bottle.

Thorotrast is a suspension containing particles of the radioactive compound thorium dioxide, ThO2, used as a contrast medium in X-ray diagnostics in the 1930s and 40s (use in some countries, such as the U.S., continued into the 1950s[1]).

The naturally abundant thorium nuclide 232Th is slightly unstable and decays through the emission of an alpha particle. Thorium compounds produce excellent images because of thorium's high opacity to X-rays (it has a high cross section for absorption). Because the suspension offered high image quality and had virtually no immediate side-effects compared to the alternatives available at the time, Thorotrast became widely used after its introduction in 1931. 2-10 million patients worldwide have been treated with Thorotrast.

Even at the time of introduction, there was concern about the safety of Thorotrast. Following injection, the drug is distributed to the liver, spleen, lymph nodes, and bone,where it is absorbed. After this initial absorption, redistribution takes place at a very slow pace. Specifically, the biological half-life is estimated to be 22 years. [1] This means that the organs of patients who have been given Thorotrast will be exposed to the alpha-radiation it emits for much of the rest of their lives. The significance of this exposure was not fully understood in 1931.

Unfortunately, Thorotrast turned out to be extremely carcinogenic, because of these alpha particles. There is a high over-incidence of various cancers in patients who have been treated with Thorotrast. The cancers occur several (usually 20-30) years after injection of Thorotrast. The risk of getting liver cancer in former Thorotrast patients has been measured to be well above 100 times the risk of the rest of the population. The risk of leukemia appears to be 20 times higher in Thorotrast patients. These observations have led some to characterize Thorotrast as the most potent human carcinogen known.

The Danish director Nils Malmros's movie, Facing the Truth (original Danish title At Kende Sandheden) from 2002, portrays the dilemma that faced Malmros's father, Richard Malmros, when treating his patients in the 1940s. Richard Malmros was deeply concerned about the persistence of Thorotrast in the body but was forced to use Thorotrast, because the only available alternative (per-abrodil) had serious immediate side-effects, suffered from image quality problems and was difficult to obtain during the Second World War. The use of Thorotrast in Denmark ended in 1947 when safer alternatives became available. Today, barium sulfate is the most commonly-used X-ray contrast medium.

Thorotrast has also been used in research to stain neural tissue samples for examination by historadiography.[2]

References

  1. Thorotrast
  2. PMID 4593184

da:Thorotrast de:Thorotrast it:Torotrasto Landmark Court Decision



Linked-in.jpg