Zobrazeno 1 - 10
of 186
pro vyhledávání: '"Jonathan G, Li"'
Autor:
Guanghua Yan, Jacqueline M. Andreozzi, Jonathan G. Li, Chihray Liu, Nicholas J. Potter, Karl Mund
Publikováno v:
Medical Physics. 47:4711-4720
Purpose Despite being the standard metric in patient-specific quality assurance (QA) for intensity-modulated radiotherapy (IMRT), gamma analysis has two shortcomings: (a) it lacks sensitivity to small but clinically relevant errors (b) it does not pr
Autor:
Guanghua Yan, Pingfang Tsai, Darren Kahler, Chihray Liu, Nicholas J. Potter, Ying Chao Hung, Jonathan G. Li, Bo Lu, Ji-Yeon Park
Publikováno v:
Medical Physics. 47:5077-5089
Purpose Directly extracting the respiratory phase pattern of the tumor using cone-beam computed tomography (CBCT) projections is challenging due to the poor tumor visibility caused by the obstruction of multiple anatomic structures on the beam's eye
Autor:
Guanghua Yan, Jonathan G. Li, Nicholas J. Potter, Bo Lu, Haitham N. Alahmad, Chihray Liu, Hongcheng Liu, Darren Kahler
Publikováno v:
Journal of Applied Clinical Medical Physics
Flattening filter free (FFF) linear accelerators produce a fluence distribution that is forward peaked. Various dosimetric benefits, such as increased dose rate, reduced leakage and out of field dose has led to the growth of FFF technology in the cli
Autor:
Haitham N. Alahmad, Chihray Liu, Guanghua Yan, Bo Lu, Jonathan G. Li, Ji-Yeon Park, Nicholas J. Potter
Publikováno v:
Medical Dosimetry. 45:197-201
The continuous delivery of volumetric modulated arc therapy (VMAT) plans is usually approximated by discrete apertures at evenly-spaced gantry angles for dose calculation purposes. This approximation can potentially lead to large dose calculation err
Publikováno v:
Journal of Applied Clinical Medical Physics
Purpose Traditionally, the treatment couch coordinates (TCCs) for patients undergoing radiotherapy can only be determined at the time of treatment, placing pressure on the treating therapists and leaving several pathways for errors such as wrong‐si
Publikováno v:
Journal of Applied Clinical Medical Physics
Purpose The use of the ionization chamber array ICProfiler (ICP) is limited by its relatively poor detector spatial resolution and the inherent volume averaging effect (VAE). The purpose of this work is to study the feasibility of reconstructing VAE
Publikováno v:
Medical Physics. 44:5627-5637
Purpose To propose a universal, parameterized gradient-based method (PGM) for radiation field size determination. Methods The PGM locates the beam profile's edge by parameterizing its penumbra region with a modified sigmoid function where the inflect
Autor:
Ji-Yeon Park, Bo Lu, Chihray Liu, Justin C. Park, Jonathan G. Li, Feifei Li, Guanghua Yan, Darren Kahler
Publikováno v:
Medical Physics. 44:2096-2114
Purpose Most VMAT algorithms compute the dose on discretized apertures with small angular separations for practical reasons. However, machines deliver the VMAT dose with a continuously moving MLC and gantry and a continuously changing dose rate. The
Efficient independent planar dose calculation for FFF IMRT QA with a bivariate Gaussian source model
Publikováno v:
Journal of Applied Clinical Medical Physics
The aim of this study is to perform a direct comparison of the source model for photon beams with and without flattening filter (FF) and to develop an efficient independent algorithm for planar dose calculation for FF‐free (FFF) intensity‐modulat
Publikováno v:
Medical dosimetry : official journal of the American Association of Medical Dosimetrists. 44(4)
Various dosimetric benefits such as increased dose rate, and reduced leakage and out of field dose have led to the growth of flattening-filter-free (FFF) technology in the clinic. In this study, we concentrate on investigating the feasibility of usin