Run-time plots of PINNACLE3 6.2b (left) and 7.6c (right) for PTV and OR data. Means for each data series are shown as broken lines. The thin line at 0% is the target for the process.
Normal probability plots. Note the transformed scale on the axes. The oblique straight line corresponds to the normal probability distribution for the standard deviation and mean of each data set. The slope of this line is inversely proportional to the standard deviation. The vertical line marks the mean (corresponding to the 50% probability).
Control charts for the four data series. The first 25 data points are plotted as circles; from these data, control lines and means are calculated. The means are plotted as dashed lines, and the upper and lower control lines are plotted as solid lines. The thin line at 0% is the target for the process. The remaining data are plotted as triangles.
Histogram of data from version 7.6c of the planning system. Dashed vertical lines show the mean; solid vertical lines indicate the narrowest specification width in which the process is capable.
Individuals control charts for PTV (top) and OR (bottom) data on the original beam model (left) and the new model (right). Thick solid lines indicate the mean; dashed lines are the upper and lower control limits; and the thin line at 0% is the target for the process.
Summary of differences between measured and planned discrepancies for all data sets. All values are expressed as percent difference between measured, , and calculated, , doses [i.e., ].
Capability indices for several specification widths.
Alterations in beam models reduced the systematic error for both PTV and OR data, and markedly reduced the specification width in which the newer model was capable.
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