Some legal problem in clinical SPECT with source as a radiation therapy treatment machines

Recent development of transmission computed tomography has legal problem that it requires the external radiation source, in the present Japanese Medical Law. The author examined inappropriate items in the present Law for the purpose of using the SPECT apparatus equipped with an external radiation source without a hitch. In the examination, inappropriate items were considered to be changed or deleted for use of the external source as follows. Important problems for the irradiating apparatus were those concerned with the interlock, automatic indicator, filter for the secondary electron and remote control. There was no serious problem concerning the irradiation tool. The common problems to above two were those concerned with the exclusive room, the item for 1 apparatus-1 room regulation and the dose standard at use at 1 m-distance. It was pointed out that harmonization of the medical law, The Law Concurring Prevention from Radiation Hazards due to Radioisotopes, etc. and Labor Safety and Sanitation Law, and consideration for incorporating the Recommendation 1990 are necessary. (K.H.)