FFF Linac Dosimetry

Improving Dose Measurement Accuracy for a Flattening-filter-free Linear Accelerator
Graduate Investigator: Megan Wood
Summary of Research: There has been a movement toward using linear accelerators with the flattening filter removed, especially for hypofractionated treatments.  The higher dose rates achievable in the flattening-filter-free (FFF) mode may be beneficial for reducing treatment times, which is especially desirable in breath-hold or breath-gated treatments.  However, many aspects of the photon beam change with the filter removed, bringing into question the reliability of current dosimetry and beam calibration methods.  The purpose of this work is to improve dose measurement accuracy in FFF beams through detector characterization and beam quality determination, including the application of a new dosimetry formalism, in order to facilitate safer and more accurate treatments using this new modality.