I.高エネルギー放射線治療装置の保守管理 : 保守記録を基にした信頼性

抄録

The most important factor needed for a routine service in radiotherapy is high order reliability of radiotherapy units. The failure analysis based on detailed maintenance records and provision of emergency repairs were required to minimized accidental trouble of machines. In this report, the factors in relation to machine reliability such as failure rate, mean time between failure, etc were described. The data used were eleven years maintenance records of betatron and linac in our hospital. Furthermore, the results of survey for 7 linacs and 5 betatrons in 11 hospitals were reported. The expected average life time of main parts such as magnetron, electron gun and doughnut were estimated. The results of failure analysis revealed that average falure rate were 1/1.5 months in linacs, 1/5 months in betatrons respectively. For high order reliability of radiotherapy machine, it is reasonable to minimize the tracing time for trouble points which were large proportion of emergency repair, and for this, the flow diagram would be useful agent. The precise and large amount of data concerned with maintenance will be desirable for the accurate estimation of machine reliability in user's side, and for the preventive maintenance. Furthermore, a fixed form of maintenance record would be better.