Analysis And Research On The Operation Reliability Of Varian2300C/D Linear Accelerator

There exists a up-raising trend in the incidence and mortality ofmalignant tumor both at home and abroad,cancer is one of the major causesof death in city resident.At present, about70%of the patients withmalignant tumor need to have radiation therapy.According to thepublication of World Health Organization(WHO) in1998,45%patients withmalignant tumor can be cured,including22%by surgical treatment,18%byradiation therapy and5%by chemotherapy.Radiation therapy plays an moreand more essential role in malignant cancer treatments.Dose comparison in the world wide,which jointly conducted by WorldHealth Organization（WHO）and International Atomic Energy Agency（IAEA）,concluded that about15%patients who had radiotherapy receivedinaccurate dose at present.However,even a tiny change of radiotherapydose can lead to a failure in the process of radiation therapy. As a mainequipment of radiation therapy,the operational reliability of medicallinear accelerator directly affect the actual effect ofradiotherapy,which is a extremely significant step in the quality controlsystem of radiation therapy.The change of linear accelerator performance and parameters may besudden or tardy, because of circuit failure, mechanical failure andcomponents aging, the accelerator performance and parameters couldchange. For cancer patients get better curative effect, on the one hand,the accelerator must demand examine and maintain for daily to ensure thatit is able to run in the best state; On the other hand, in order to improveequipment utilization, and reduce hospitalization time caused byequipment failure, and so on, timely the common pitfalls and failure ofaccelerator must be analyzed and removed. Combined with our existing medical equipment, this thesis mainlycarried out the following two aspects work:(1) the processing methodsof the accelerator fault (2) the measurement of accelerometer output dose.According to the record analysis of accelerator operation failure andfailure process (potential) In nearly two years, we draw the followingconclusions:(1) the accuracy of the accelerometer output dose and frame,such as collimator, treatment bed has a close relationship, especiallythe relationship between frame, laser, light field;(2) linearaccelerator is a kind of large medical instrument, very easy to cause allkinds of faults. On the analysis and research of the potential faults andfault handling for linear accelerator will be favor for the engineer,physical and technical personnel to grasp the running situation of theaccelerator, to reduce the incidence of accelerator fault, to cup downmaintenance costs department, to improve the utilization rate of theaccelerator,to reduce incidence to prolong tumor patientshospitalization time caused by equipment failure, to make theaccelerator can produce much more social and economic benefits.