Characterization of Dosimeters for Small Field Applications Including Comparisons to Monte Carlo and Treatment Planning System Computed Doses
Date
2023-01-04
Authors
Timakova, Elena
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Abstract
In radiation therapy, accurately determining the dose to a patient is extremely important for optimal patient outcomes and efficient clinical flow. Under small field conditions, experimental dosimetry is difficult due to fluence perturbation effects and computational dosimetry poses challenges related to limits on computation time. In this work, two novel dosimeters were characterized for important properties of a small field dosimeter. Then, the dosimeters’ performance was compared to treatment planning system dose algorithms and Monte Carlo methods. The new dosimeters showed promising results with relatively little effort put towards set-up and measurement acquisition for normal clinical conditions. Good agreement was seen for isocentric clinical SRT plan delivery with targets around 2 cm in diameter and modulation scores of around 5 MU/cGy. As field sizes fall below 1 x 1 cm2, fields move off axis, and/or plans increase in modulation score beyond 5 MU/cGy, disagreements begin to emerge.