PROCEEDINGS OF THE 7 INTERNATIONAL ... - Fizika
PROCEEDINGS OF THE 7 INTERNATIONAL ... - Fizika
PROCEEDINGS OF THE 7 INTERNATIONAL ... - Fizika
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A. Meijers et al. / Medical Physics in the Baltic States 7 (2009) 56 - 59<br />
4. Conclusions<br />
Developed tool is easy usable and appropriate for EQSQ<br />
calculation of irregularly shaped fields, which can be<br />
used for manual MU verification. It is easy adjustable<br />
for different machines and beam energies.<br />
Statistically it was determined that optimal number of<br />
vectors for EQSQ calculation is 24. Basic verification of<br />
tool showed that EQSQ can be determined with error<br />
1.32 ± 0.52 %. Such EQSQ error would result in<br />
calculated MU error 0.042 ± 0.021 %.<br />
EQSQ values calculated by developed tool were<br />
compared with values calculated by TPS system with<br />
PBC dose calculation algorithm. Difference between<br />
both results was 1.83 ± 0.85 %.<br />
59<br />
To successfully implement this tool qualitative SMR<br />
data are necessary. If SMR are calculated from PDD<br />
data, it is suggested to measure PDD for 0 × 0 cm field.<br />
For further verification of the tool, it would be<br />
necessary to carry out measurements to determine<br />
whether actual PDD of square field as calculated by the<br />
tool is the same as for given irregularly shaped field.<br />
5. References<br />
1. Khan F. M., The Physics of Radiation Therapy,<br />
Lippincott Williams & Wilkins, Philadelphia, 2003.<br />
p. 511.<br />
2. British Journal of Radiology, 1996, Supplement No.<br />
25.