Table 2.

Tests included in the proposed quality management program and recommended tolerances for long-term consistency measures.

Performance	Tests	Tolerance
Output consistency	Measure dose-rate the at isocenter using an appropriately calibrated ion chamber	± 1%
Image resolution consistency / Object representation	Use a CBCT scan of the imaging phantom to derive diameters of all resolution air cavities by vertical and horizontal line profiles. Derive distances between cavities from the same line profiles. Check the length and diameter of the imaging phantom in a sagittal slice.	± 0.2 mm for resolution ± 0.5 mm for distances ± 1.0 mm for object size representation
Accuracy of image- guided target localization	Locate a well-defined target using the high-CT density BB phantom and then verify that its location identified on the CBCT coincides with the radiation isocenter using the 5 × 5 mm2 collimator at gantry angles 0° and 90°.	± 0.5 mm
Dose calculation consistency	Calculate a four-field 10 × 10 mm2 treatment plan for 10 Gy on a reproducible isocenter in the imaging phantom and record the treatment times.	± 2 s (± 3%) per treatment field