Radioisotopes, cancer detection

Specific targeting of radioisotopes or toxic drugs to tumors for cancer detection and treatment is an enticing but elusive goal. It has proved difficult to achieve adequate concentration ratios between tumor and normal tissues to improve on standard diagnostic and therapeutic methods. 

The radioisotope, iridium-192, is used to treat cancer and to take X-ray pictures of metal castings to detect flaws. Iridium is also used as a catalyst for several chemical reactions. 

There are some recent examples of theranostics where ln has been loaded onto nanoparticles. An immunoliposome anchored with internalising human antibody, scFv, and radiolabelled with ln showed tumour selectivity and due to the possibility of loading with a drug, potential for simultaneous detection and therapy of cancer. Multimodal imaging of liposomal drugs where radioisotopes were combined with chemother-apeutics, with F-FDG PET and bioluminescence (to assess efficacy) and... 

In its nuclear medicine business, MDS Nordion remains the world s number one producer of medical isotopes. Radiopharmaceutical producers on five continents use its radioisotopes to make their products. It supplies two-thirds of the reactor-produced isotopes used in the world as well as a wide variety of cyclotron-produced isotopes. Its market leadership continues to be based in its position as the leading supplier of molybdenum-99, the source of technetium 99m, the most important isotope for nuclear medicine. While planning to strengthen its position as the leading supplier of bulk isotopes, MDS Nordion continues to look to the development of its own radiopharmaceutical products as the key to growth in the future. Many of these products help detect medical conditions, but some of the latest ones can aaually treat diseases. MDS Nordion is already selling radiopharmaceuticals for certain types of cancer therapy. 

---