[Current status of nuclear medicine in Japan]

Radionuclides have been used for the diagnosis and therapy of cancers. In Japan, about 1.8 million studies are performed annually, especially on bone, the heart, the brain and cancer. In contrast to anatomical studies with X-ray, US or CT, nuclear medicine provides physiological or metabolic images. The characteristics of nuclear medicine come from the use of tracer studies employing various radiopharmaceuticals. The most commonly used radionuclides for cancer studies are 67Ga and 201T1. Recently, however, many other radiopharmaceuticals with tumor specificity have been developed, such as 99mTc labeled monoclonal antibodies and 111In labeled octreotide. 18F-FDG, which images glucose metabolism, is very useful in the management of lung, colorectal and other cancers. Furthermore, radionuclides are also employed in the therapy of cancer, such 131I-labeled anti-CD20 antibody for the B-cell lymphoma and 89Sr for the palliation of bone pain caused by prostate and breast cancer metastases.