Radioactive metal compounds used in diagnosis and treatment of diseases

This review describes about radioactive metal compounds used in the medical field, which are given in the human body. They emit gamma ray or beta ray in the body and the radiation is used for imaging diagnosis or internal radiotherapy, respectively. The gamma ray gives the whole body image measurable within a short time and the tissue functional time change is easily observable, which are importantly different from X-CT and MRI images. For the purpose, radiopharmaceuticals labeled by 67Ga, 99mTc, 111In and 201Tl are used for diagnoses of the brain (blood flow), heart (pump function and myocardial blood flow), bone, thyroid, kidney and tumor, and novel ones are under development for more specific diagnosis of tumors, neuro-transmitting and other functions. The beta ray is suitable to kill tumor cells due to its range and energy and such radiopharmaceuticals as labeled by 64Cu, 89Sr, 90Y and 186Re are thought to be applicable to the internal radiotherapy by their property to distribute to the bone or to form a complex with antibody for missile therapy (radioimmunotherapy). Metals emitting gamma ray as well can externally give images of their distribution. Knowledge accumulated in future of the radioactive metal compounds in the body will be useful for further development of new diagnostic and therapeutic ones. (T.I.)