Výsledky vyhledávání - "W A, Beckham"

The effect of leaf width and sampling distance on the 'stair-stepping' of field borders defined by multileaf collimators

Autor: P B, Greer, W A, Beckham

Publikováno v: Australasian physicalengineering sciences in medicine. 26(2)

Standard multileaf collimators (MLCs) are now available with 1.0 and 0.5 cm leaf widths. The aim of this work is to compare the dose-undulation and effective penumbra of field edges formed by these MLC leaf widths and to determine how reducing the sa

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=pmid________::6a50fd19a57d374405aab4096b7052b4
https://pubmed.ncbi.nlm.nih.gov/12956185

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A method to predict the effect of organ motion and set-up variations on treatment plans

Autor: P J, Keall, W A, Beckham, J T, Booth, S F, Zavgorodni, M, Oppelaar

Publikováno v: Australasian physicalengineering sciences in medicine. 22(2)

Dose distributions calculated by commercial treatment planning systems do not allow incorporation of the effects of patient position variation or organ motion throughout the course of radiation therapy treatment. We have established a convolution-bas

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=pmid________::451f4226789d2af2e55eac5449b17370
https://pubmed.ncbi.nlm.nih.gov/10474975

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Photon buildup in orthovoltage X-ray beams

Autor: R F, Hill, P J, Keall, W A, Beckham, M D, Perez

Publikováno v: Australasian physicalengineering sciences in medicine. 21(2)

Orthovoltage x-ray beams exhibit the characteristic of depth dose buildup which is not well described in the literature. The principal reason for this phenomenon is the increase in dose deposited due to electrons set in motion by secondary (Compton)

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=pmid________::35f2fdc5354edc33bb670a040b3d4d1c
https://pubmed.ncbi.nlm.nih.gov/9745790

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An independent check method of radiotherapy computer plan derived monitor units

Autor: R F, Hill, M D, Perez, W A, Beckham

Publikováno v: Australasian physicalengineering sciences in medicine. 21(2)

With the increasing complexity of radiotherapy computer treatment planning systems (CTPS), verification of the treatments is an important component of a quality assurance program. The radiation dose delivered to a patient is based on treatment machin

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=pmid________::790060d9ce06a35f3f55ea0f117e84f6
https://pubmed.ncbi.nlm.nih.gov/9745794

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Secondary electron scatter in radiotherapy: implications for treatment fields in proximity to the lens of the eye and the testes

Autor: W A Beckham

Publikováno v: Physics in medicine and biology. 38(7)

For external beam photon radiotherapy treatments, secondary electrons pose unique shielding problems. Dose due to these electrons can be deposited under shielding blocks and also outside of collimated beam edges. The sources of contamination electron

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::62eaecf3a5bfa2e21cea7dedfa34c546
https://pubmed.ncbi.nlm.nih.gov/8372105

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The use of a BF3 remmeter to calibrate neutron activation foils in the medical linear accelerator environment

Autor: I M, Borchardt, W A, Beckham, G C, Sorell, A H, Beddoe

Publikováno v: Australasian physicalengineering sciences in medicine. 15(2)

A technique has been developed for radiation protection purposes whereby it is possible to measure the dose-equivalent due to neutrons from a dual energy medical linear accelerator using a conventional BF3 neutron remmeter to calibrate gold foils. Th

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=pmid________::46ec28d6e3bd31e91a147c4a66173718
https://pubmed.ncbi.nlm.nih.gov/1642569

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