Application of EPID in Consistency Detection of Accelerator Light and Radiation Field
Objective To compare slow sensitive film and electronic portal imaging device(EPID),so as to explore an accurate,efficient and economical method for checking the consistency of accelerator light and radiation field.Methods In the weekly accelerator quality control process,slow sensitive film and EPID were separately used to check the light and radiation field consistency of 6 MV X-rays at a light field of 10 cm × 10 cm of Synergy medical electron linear accelerator,which lasted 20 weeks.Then,the difference between the two methods in checking the consistency of the accelerator light and radiation field was analyzed statistically.Results The light and radiation field consistency of 6 MV X-rays at a light field of 10 cm×10 cm of the Synergy accelerator in X1,X2,Y1 and Y2 directions checked by slow sensitive film and EPID both met the performance requirements specified in NCC/T-RT 001-2019"Quality Control Guidelines for Medical Electronic Linear Accelerators".The results of the consistency of light and radiation field checked by the slow sensitive film and EPID,in the X1 direction were(0.29±0.40)and(0.16±0.41)mm,in the X2 direction were(-0.04±0.30)and(-0.14±0.38)mm,in the Y1 direction were(0.13±0.32)and(0.26±0.35)mm,and in the Y2 direction were(-0.20±0.33)and(-0.18±0.34)mm,respectively.Finally,there were no statistical differences in the consistency of light and radiation field checked between slow sensitive film and EPID in the X1,X2,Y1 and Y2 directions(P>0.05).Conclusion Compared with slow sensitive film,EPID has a good consistency in checking the consistency of light and radiation field.Moreover,EPID has the characteristics of accuracy,efficiency and economy.Thus,it can be used to check the consistency of accelerator light and radiation field.
acceleratorelectronic portal imaging deviceconsistency of light and radiation fieldslow sensitive filmquality control