The search for an ideal radioisotope for radiotherapy continues. As a generator - produced radioisotope emitting both beta and gamma rays with a short physical half-life of 16.9 hr. 188 Re in an excellent candidate for radiotherapy. Its applications include the irradiation of coronary artery to prevent restenosis, treatment of rheumatoid arthritis, treatment of peritonedal effusion, palliation of metastatic bone pain, and treatment of liver cancer. ( Korean J Nucl Med 2001;35:293-300)