Long-term evaluation and cross-checking of two geometric calibrations of kV and MV imaging systems for Linacs.

ABSTRACT: Geometric or mechanical accuracy of kV and MV imaging systems of two Varian TrueBeam linacs have been monitored by two geomertirc calibration systems, Varian IsoCal geometric calibration system and home-developed gQA system. Results of both systems are cross-checked and the long-term geometric stabilities of linacs are evaluated. Two geometric calibration methodologies have been used to assess kV and MV imaging systems and their coincidence periodically on two TrueBeam linacs for about one year. Both systems analyze kV or MV projection images of special designed phantoms to retrieve geometric parameters of the imaging systems. The isocenters — laser isocenter and centers of rotations of kV imager and EPID — are then calculated, based on results of multiple projections from different angles

SUBMITTER: Chiu TD 

PROVIDER: S-EPMC5690018 | biostudies-literature | 2015 Jul

REPOSITORIES: biostudies-literature