RESUMO
PurposeTo perform a quality assurance program for Truebeam imaging system using MIMI phantom, and to evaluate the accuracy of the imaging system center with the radiation isocenter and the accuracy of couch shift.Materials and Methods The reference images of MIMI phantom were acquired using CT scanner. The reference images were imported into the treatment planning system and a simple plan was created. The MIMI phantom was placed on the treatment couch. The images were acquired using the MV/KV imaging system, and a match registration was performed with the reference images from the TPS.Results Measured over six months, the precision of the imager and linac's isocenter was <1 mm, and the couch shift accuracy was <1 mm. The measurements over six months demonstrate that isocenters of the MV/KV imaging systems on Truebeam system are stable.Conclusion The accuracy of the Truebeam imaging system center and couch shift is safe and reliable. The error of Truebeam imaging system center and couch shift can be tested on a monthly base.
