[Current status of nuclear oncology in Japan]

The most commonly used radionuclides for cancer patients in Japan have been still 67Ga and 201T1 chloride. In addition to the diagnosis of lung cancer and thyroid tumor, 201T1 is recently applied to patients with brain tumor, bone and soft tissue tumor and parathynoid adenoma. Comparing to Nuclear Cardiology and Brain Nuclear Medicine, where many new radiopharmaceuticals have been developed, there are few new drugs in Nuclear Oncology. In other words, new radiopharmaceuticals are expected to be developed for the diagnosis and/or therapy of cancer. In addition to 131I for thyroid cancer, new radiopharmaceuticals such as 111In-octreotide and 99mTc(V)-DMSA have been clinically employed. In spite of strong expectation, radiolabeled monoclonal antibodies have not been clinically used in Japan. However, the technique of humanized antibodies has been established and in U.S.A., 131I-labeled antibodies are reported to be effective for the treatment of malignant lymphoma. 89Sr is useful for the relief of bone pain caused by the bone metastasis. New findings that SPECT of 18F-FDG, a positron emitter, has been revealed to have a great potential in the management of cancer patients, will give a great impact on Nuclear Oncology.