Browsing ICR Divisions by author "Bedford, James L"
Now showing items 1-11 of 11
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A method to verify sections of arc during intrafraction portal dosimetry for prostate VMAT.
Bedford, JL; Hanson, IM (2019-10-16)This study investigates the use of a running sum of images during segment-resolved intrafraction portal dosimetry for volumetric modulated arc therapy (VMAT), so as to alert the operator to an error before it becomes ... -
Assessment of the robustness of volumetric-modulated arc therapy for lung radiotherapy
Edmunds, K; Bedford, J (Oxford University Press (OUP), 2013-03-01)Volumetric-modulated arc therapy (VMAT) is increasingly popular as a treatment method in radiotherapy owing to the speed with which treatments can be delivered. However, there has been little investigation into the effect ... -
Beam modeling and VMAT performance with the Agility 160-leaf multileaf collimator.
Bedford, JL; Thomas, MDR; Smyth, G (2013-05-06)The Agility multileaf collimator (Elekta AB, Stockholm, Sweden) has 160 leaves of projected width 0.5 cm at the isocenter, with maximum leaf speed 3.5 cms-1. These characteristics promise to facilitate fast and accurate ... -
Calculation of absorbed dose in radiotherapy by solution of the linear Boltzmann transport equations.
Bedford, JL (2019-01-10)Over the last decade, dose calculations which solve the linear Boltzmann transport equations have been introduced into clinical practice and are now in widespread use. However, knowledge in the radiotherapy community ... -
A discrete ordinates Boltzmann solver for application to inverse planning of photons and protons.
Bedford, JL (IOP Publishing, 2023-08-29)The aim of this work is to develop a discrete ordinates Boltzmann solver that can be used for calculation of absorbed dose from both photons and protons within an inverse planning optimizer, so as to perform accurate dose ... -
Dose prescription with spatial uncertainty for peripheral lung SBRT.
Bedford, JL; Blasiak-Wal, I; Hansen, VN (2019-01)Current clinical practice is to prescribe to 95% of the planning target volume (PTV) in 4D stereotactic body radiotherapy (SBRT) for lung. Frequently the PTV margin has a very low physical density so that the internal ... -
Functional lung avoidance in radiotherapy using optimisation of biologically effective dose with non-coplanar beam orientations.
Bedford, JL; Ahmed, M (ELSEVIER, 2023-10-01)BACKGROUND AND PURPOSE: In external beam radiotherapy for non-small cell lung cancer, dose to functioning lung should be minimised to reduce lung morbidity. This study aimed to develop a method for avoiding beam delivery ... -
Inverse planning of lung radiotherapy with photon and proton beams using a discrete ordinates Boltzmann solver.
Bedford, JL (IOP Publishing Ltd, 2024-02-02)Objective. A discrete ordinates Boltzmann solver has recently been developed for use as a fast and accurate dose engine for calculation of photon and proton beams. The purpose of this study is to apply the algorithm to the ... -
Optimisation of a composite difference metric for prompt error detection in real-time portal dosimetry of simulated volumetric modulated arc therapy
Bedford, JL; Hanson, IM (British Institute of Radiology, 2021-04-01)Objectives: In real-time portal dosimetry, thresholds are set for several measures of difference between predicted and measured images, and signals larger than those thresholds signify an error. The aim of this work is to ... -
A recurrent neural network for rapid detection of delivery errors during real-time portal dosimetry
Bedford, JL; Hanson, IM