The Comparison of Beam Data between Measured Beam Data and Calculated Beam Data Using Treatment Planning System / 의학물리

ABSTRACT

The first step in the commissioning procedure of a treatment planning system is always verification of the basic beam data. In this work, we have measured PDD curves and beam profiles between 1x1 cm2 and 40x40 cm2. In an attempt, Pinnacle 7.4f detect discrepancies between predicted dose distribution and delivered dose distribution. The discrepancies between measurement data and caculation data was found. The delivered dose was underestimated in field but overestimated out of field. The Dmax depth of 1x1 cm2 was reduced about 2 mm. For the larger field size (> or = 4x4 cm2), the beam profile and PDD curve showed good agreement between measurement data and calculation data.