Sirtex Medical Limited is a biotechnology and medical device company. The Company is engaged in manufacturing and to distribute liver cancer treatments utilizing particle technology to approved markets in Asia-Pacific, Europe and the United States. It manufactures and distributes SIR-Spheres microspheres. SIR-Spheres microspheres are microscopic radioactive polymer spheres that contain yttrium-90 (Y-90) and emit beta radiation. The Company supply its SIR-Spheres microspheres product from its manufacturing plants in the United States and Singapore, as well as from the Australian Nuclear Science and Technology Organisation (ANSTO) in Sydney. Its subsidiaries include Sirtex Medical Products Pty Ltd, Sirtex Global Pty Ltd, Sirtex Technology Pty Ltd, Sirtex SIR-Spheres Pty Ltd, Sirtex Thermospheres Pty Ltd, Sirtex Singapore Holding Pte Ltd and Sirtex Medical Singapore Pte Ltd.