PURPOSE: This study evaluated the setup uncertainties for brain sites when using BrainLAB's ExacTrac X- @entity16039 6D system for daily pretreatment to determine the optimal planning target volume ( @entity343 ) margin. METHODS: Between August 2012 and April 2015, 28 @entity1 with @entity1313 were treated by daily image-guided radiotherapy using the BrainLAB ExacTrac 6D image guidance system of the Novalis-Tx linear accelerator. DUONTM (Orfit Industries, Wijnegem, Belgium) masks were used to fix the head. The radiotherapy was fractionated into 27-33 treatments. In total, 844 image verifications were performed for 28 @entity1 and used for the analysis. The setup corrections along with the systematic and random errors were analyzed for six degrees of freedom in the translational (lateral, longitudinal, and vertical) and rotational (pitch, roll, and yaw) dimensions. RESULTS: Optimal @entity343 margins were calculated based on van Herk et al.'s [margin recipe = 2.5  - + 0.7   - 3 mm] and Stroom et al.'s [margin recipe = 2  - + 0.7  ] formulas. The systematic errors (  -) were 0.72, 1.57, and 0.97 mm in the lateral, longitudinal, and vertical translational dimensions, respectively, and 0.72  , 0.87  , and 0.83   in the pitch, roll, and yaw rotational dimensions, respectively. The random errors (  ) were 0.31, 0.46, and 0.54 mm in the lateral, longitudinal, and vertical rotational dimensions, respectively, and 0.28  , 0.24  , and 0.31   in the pitch, roll, and yaw rotational dimensions, respectively. According to van Herk et al.'s and Stroom et al.'s recipes, the recommended lateral @entity343 margins were 0.97 and 1.66 mm, respectively; the longitudinal margins were 1.26 and 3.47 mm, respectively; and the vertical margins were 0.21 and 2.31 mm, respectively. CONCLUSION: Therefore, daily setup verifications using the BrainLAB ExacTrac 6D image guide system are very useful for evaluating the setup uncertainties and determining the setup margin.  -  .

SU-F-J-24: Setup Uncertainty and Margin of the ExacTrac 6D Image Guide System for @entity1 with XXXX .

@entity1 :: ('9606', 'Species') :: ['patients'] @entity343 :: ('187978', 'Species') :: ['PTV'] @entity16039 :: ('255564', 'Species') :: ['ray'] @entity1313 :: ('MESH:D001932', 'Disease') :: ['brain tumors']
@entity1313 :: (MESH:D001932,Disease) :: ['Brain Tumors']
