Kayla N. Kielar

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PURPOSE To determine how the respiratory phase impacts dose to normal organs during stereotactic body radiation therapy (SBRT) for pancreatic cancer. METHODS AND MATERIALS Eighteen consecutive patients with locally advanced, unresectable pancreatic adenocarcinoma treated with SBRT were included in this study. On the treatment planning 4-dimensional(More)
The Varian's new digital linear accelerator (LINAC), TrueBeam STx, is equipped with a high dose rate flattening filter free (FFF) mode (6 MV and 10 MV), a high definition multileaf collimator (2.5 mm leaf width), as well as onboard imaging capabilities. A series of end-to-end phantom tests were performed, TrueBeam-based image guided radiation therapy(More)
Recent advances in physical models of skeletal dosimetry utilize high-resolution 3-dimensional microscopic computed tomography images of trabecular spongiosa. These images are coupled to radiation transport codes to assess energy deposition within active bone marrow and trabecular endosteum. These transport codes rely primarily on the segmentation of the(More)
PURPOSE With the introduction of flattening filter free (FFF) linear accelerators to radiation oncology, new analytical source models for a FFF beam applicable to current treatment planning systems is needed. In this work, a multisource model for the FFF beam and the optimization of involved model parameters were designed. METHODS The model is based on a(More)
PURPOSE To determine the distribution of photon spectrum on flattening filter free (FFF) beams, novel and fast optimization methods that were applicable on a convolution/superposition dose calculation algorithm were implemented. METHODS Two-step optimization method was designed to model the virtual photon spectrums for FFF beams. At first, simple(More)
PURPOSE The dosimetric leaf gap (DLG) in the Varian Eclipse treatment planning system is determined during commissioning and is used to model the effect of the rounded leaf-end of the multileaf collimator (MLC). This parameter attempts to model the physical difference between the radiation and light field and account for inherent leakage between leaf tips.(More)
This study was focused on a new beam source modeling technique for a flattening filter free (FFF) beam. The model was based on a previous three source model, and improved by introducing off axis ratio (OAR) of photon fluence to the primary and scattered photon sources to generate cone shaped dose profiles. The model parameters and the OAR were optimized(More)
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