The Compare of the Position Accuracy of Varian Multileaf Collimator With Different Gantry Angle
MA Guang-dong · Zhongguo yixue wulixue zazhi · 2012
Objective:To compare the position accuracy of Varian multileaf collimator between different gantry angle with dynamic therapy log file(Dynalog Files).Methods: We run the prepared dynamic therapy planning MLC file which named PMLC(Planning MLC) in five different gantry angle(270°,315°,45°,0°,90°) 10 times,and record dynalog files every times;then convert them into MLC format files which named DMLC(Delivery MLC),analyse the position accuracy with different gantry angle,and compare the position accuracy dissimilarity with gantry angle is 0°.Results: Totally 40% of the leaf position deviation is no more than 0.2 mm and 40% of the leaf position deviation is between 0.3 mm to 0.4 mm,20% of the leaf position deviation is 0.5 mm,the biggest deviation value is 0.5 mm;about 95% of the leaf position value in 10 times during treatment is consistent,other leaves position deviation are no greater than 0.1 mm.Conclusions: The position accuracy of multileaf collimator with different gantry angle is no significant difference,and it indicates that the target location is precise of the patient during treatment.