VSI CyberKnife Round And Iris Collimator Comparison And Analysis Of The Physical Characteristics

After many years development of the CyberKnife,as a radiosurgery system,it has now become a body capable of any part(including prostate,lung,brain,liver,spine,pancreas and kidney)and non-malignant non-invasive cancer treatment techniques.Due to its collection of high-dose-rate accelerator arm collimator replacement system,real-time monitoring of low-dose imaging systems,tracking systems,etc.For the treatment of patients to provide more possibilities.We can be more incident direction to design better programs to complete the treatment of patients.The VSICyberKnife compared with the previous G4,not only equipped with a new fixed circular collimator,but also a newVariable Aperture Collimator(Iris);at the same time,increasing the treatment of such incident node the incident direction of the plan can be applied has been greatly improved.Iris collimator as faster switching speeds for the treatment of portal saves time,but also makes more kind of plan to be implemented.However,when using two different collimators,wether we can get the rays that have the same or similar physical characteristics,whether related to the patient can be the key to correct and effective treatment.This paper analyzed and discussed with the semiconductor detector PTW60017,finger-type ionization chamber PTW30013 other measuring Fifth Generation CyberKnife VSI fixed circular collimators and Iris Variable Aperture Collimator under 12 different sets aperture(diameter 5mm ~ 60mm)various physical properties,including radiation field half field size at each aperture,the size of the radiation field is formed,as well as flatness and symmetry of the two kinds of collimator dose distribution.Round and Iris collimator shot through contrast.The use of film and other analysis AQA EBT3 dose monitoring and detecting the comparative results of E2 E.With different parameters for each aperture diameter collimator comparative analysis Iris variable aperture collimator and the circular collimator fixed dose compared to meeting the needs of the clinical characteristics of treatment,the treatment time is shortened to meet the base dose distribution satisfactory.Finally,for safety analysis oftwo different collimator,daily use dose reproducibility analysis comparing objective evaluation offs between the two collimators.Measurement results showed that the fixed circular collimators and Iris variable aperture collimator penumbra values in the X and Y axes are with the radiation field increases,ranged from 2mm ~ 6.5mm,two kinds of collimation It is always less than the difference between 0.2mm;each of the radiation field aperture area in the X and Y axes and two kinds of collimators deviation range 0 ~ 2.6mm.When 40 mm flatness and symmetry were less than 14% and 2%,the error between the two collimators were less than 0.26% and 0.6%.Wear radio than the comparative results were less than 1%,0.36% difference between the two.AQA test results and test results were E2 E meet clinical needs,and both error is small.Round fixed collimator and Iris variable aperture collimator can reach the CyberKnife requirements to meet clinical needs.Iris collimator based on this conversion faster,more time-saving treatment.