Dosimetric control of dose distribution calculated in computerized treatment planning system

METHODS

Fields measured by Farmer, Semiflex and PinPoint ion
chambers were created in CTPS. Using Linear 2D-Array,
measurements were done in open, isocentric, oblique and
wedge filtered fields which created in CTPS. Dose values were
compared.

RESULTS

PinPoint ion chamber measured top dose values whereas
Farmer ion chamber measured low values. The most compatible
results with CTPS were obtained by Semiflex ion chamber.
However, in 2D-Array measurements, concordance was
observed with CTPS in central axis, difference reached 20 %
in build-up and penumbra regions.

CONCLUSION

The most compatible results with CTPS were obtained by
Semiflex ion chamber. Reasons of discordance in 2D-Array
measurements were found as; varible dose around build-up
region, and not to obtain the exact superpose of profiles' penumbra
region.

Keywords: Computerized treatment planning system; linear 2Darray; quality assurence in radiotherapy