Three corrections for overshoot effect improved the dose for step-and-shoot intensity-modulated radiation therapy.

ABSTRACT: We measured the overshoot effect in a linac and reduced it using block correction, reverse-sequence correction, and index correction. A StarTrack detector was used on a Varian iX. Five segments, 1 × 10 cm2 in area, were designed; the centers were at -4, -2, 0, 2, and 4 cm on the x axis for measuring the overshoot effect on a 10 × 10 cm2 collimator setting. Block correction was applied to two segments. The first was on the new first segment at -6 cm, and the other was on the new last segment at 6 cm. Both two new segments were obtained from the 10 × 10 cm2 collimator setting. The order of segments was reversed in reverse-sequence correction. Reverse-sequence correction averages the dose at every segment after two irradiations. When we used MLC Shaper, index correction reduced the first segm

SUBMITTER: Yu CY 

PROVIDER: S-EPMC8064569 | biostudies-literature | 2021

REPOSITORIES: biostudies-literature