Dose calculation software for helical tomotherapy, utilizing patient CT data to calculate an independent three-dimensional dose cube
A typical projection, segmented into segments. The overall shape represents the full projection; each of the 64 leaves is potentially open for a different time. The example shows a projection where only seven central leaves are used. The segmentation breaks this down into a group of fields (numbered 1–7 in this example), where each field has a number of adjacent leaves open together for the same time.
A typical screen shot from the software. The top image shows the sinogram. The other images (clockwise from top left) show the independent dose calculation, the TomoTherapy calculation, a gamma histogram, and a gamma map.
Output factors, measured 100 mm deep in water, for field width 50 mm (solid line with squares) and 25 mm (dotted line with triangles).
Tissue phantom ratios for fields with equivalent square sizes 10, 25, 50, 7, and 89 mm.
(a) Example of in-plane profiles. The dashed line is for the full field (all 64 leaves open), whilst the solid line is for two groups of four leaves open, one at the centre and one offset. (b) The ratio of the profile for four open leaves to that for 64 open leaves, at depths 15, 50, 100, and 200 mm. The lines are for symmetric fields, the points are for asymmetrically offset fields. The x-axis is the angular distance from the middle of the field, in milliradians.
Percentages of points within the 50% isodose surface that give a gamma value ≤1, for ten patients having prostate radiotherapy.
The result of simulating errors (shifting and/or adding dose) to the ten prostate plans in Table I.
Percentages of points within the 50% isodose surface that give a gamma value ≤1, for ten patients having head and neck radiotherapy.
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