The Study Of Patient Dose Verification Based On Three-dimensional Anatomical Information

For the complexity of the techniques of IMRT, dose verification of the treatmentplan for the patients before and during the treatment is necessary. However, thecurrently used dose verification method cannot completely show the dose calculate andexecution of the plan, and cannot provide us with the precise anatomical position whenerrors occur.This study reviewed the current methods and the instrument applications of doseverification, introduced the researches and applications of3-dimentional doseverifications. It deeply explored the quality-control system-CompassRstructure, thecomputation of the mathematical model, and the theory of measurement ofreconstructing dose distribution。 Measured beam data of accelerators and constructedCCC dose calculation model.Through testing a series of square-wave chart patterns MLC fields and complicatedIMRT Phantom lung plans，this study both verified the precision of Compass systembased on reconstruction of measurements and the independently computed dose, andevaluated the reliability of its clinical practices。 It is discovered that although theprecision of the reconstruction of dose might get lower under certain circumstances,CompassRsystem was still favorably precise, and could provide the information aboutboth the errors of volume dose relevant to the anatomical structures of the patients, andthe positions of the errors, and this helped us to evaluate the errors’ impact on clinicaltreatment.This study used Compass system to3-dimentionly verify the dose of esophagealcarcinoma IMRT plans based on the anatomical information of the patients. It selected12plans of esophageal carcinoma IMRT, used Compass system to verify dose3-dimentionly, evaluatedquantitative parameters of dose–volume relationships to thePTV and critical structures. Meantime, it used MatriXX to2-dimentionally verify thedose. Apart from providing errors of dose distribution and Gamma passing rates, usingCompass system to3-dimentionally verify the dose could define volumetric dosimetryof PTV and critical structures，and accurately showed the specific position of the errors,providing more information to evaluate the feasibility of the plans. So it is moremeaningful in instructing treatment than using2-D dose verifications. Three-dimensional dose verification with CompassRcan provide additionalinformation to comprehensively evaluate the plan which is benefit for evaluating theclinical value of verification...