title: A statistical analysis of ionometrically measured 6-MV x-ray beam parameters.
abstract: A statistical analysis has been made of ionometrically measured parameters related to the central-axis output, the beam symmetry, the beam flatness, and the depth dose for the 6-MV x-ray beam from the Therac-6 linear accelerator. The means and coefficients of variation of the measurements are determined on a monthly basis for each parameter. Mean coefficients of variation less than +/- 1% have been determined and are useful in establishing the optimal limits of acceptance of these parameters. The results of this study indicate that the long-term stability of the radiation parameters associated with this unit can be maintained within acceptable limits with a consistent quality-assurance program.
mesh_terms: D006801:Humans; D010315:Particle Accelerators / Q000592:standards*; D011785:Quality Assurance, Health Care; D011874:Radiometry / Q000295:instrumentation; D011879:Radiotherapy Dosage; D011882:Radiotherapy, High-Energy / Q000592:standards*