Varian Medical Systems buys Sirtex Medical to add radiation medicine to its portfolio for cancer treatments. This acquisition is the latest step in Varian’s long-term strategy to become a global leader in multidisciplinary integrated cancer-care solutions. Sirtex specializes in treatment for liver cancer. Its lead product is SIR-Sphere, radioactive beads that deliver high doses of radiation to liver tumors. The therapy is approved in the US, the European Union, and Australia. Sirtex has manufacturing capabilities in the US, Singapore, and Germany.