Tissue Inhomogeneity Corrections for Megavoltage Photon Beams

10.37206/86 ◽  
2004 ◽  
Author(s):  
Nikos Papanikolaou ◽  
Jerry J. Battista ◽  
Arthur L. Boyer ◽  
Constantin Kappas ◽  
Eric Klein ◽  
...  
Keyword(s):  
Photon Beams ◽  
Tissue Inhomogeneity

Feasibility of using 6 MV photon beams in contrast-enhanced radiotherapy

2017 ◽  
pp. 57-61
Author(s):  
E. S. Vorobyeva ◽  
◽  
A. A. Lipengolts ◽  
A. A. Cherepanov ◽  
E. Yu. Grigorieva ◽  
...  
Keyword(s):  
Photon Beams ◽  
Contrast Enhanced

Comparison between different boost dose delivery techniques to the tumor bed of right sided breast cancer patients.

2017 ◽  
Vol 13 (1) ◽  
pp. 4605-4617
Author(s):  
Aly Mahmoud El-Hdidy
Keyword(s):  
Breast Cancer ◽  
Cancer Patients ◽  
Target Location ◽  
Breast Cancer Patients ◽  
Photon Beams ◽  
Lung Dose ◽  
Dose Volume Histograms ◽  
Tumor Bed ◽  
Boost Dose ◽  
Treatment Plans

Comparisons between three different techniques by which the boost dose was delivered to the tumor bed were carried out , aiming to present the best technique of treatment for right breast cancer patients.In this study, ten right sided breast cancer computed tomography (CT) scans were selected for ten early right breast cancer patients. We made three different treatment plans for each patient CT using three different irradiation techniques to deliver a prescribed boost dose of 10 Gy in 5 fractions to the boost PTV. In the first technique, two tangential photon beams were used, in the second technique we, two oblique photon beams were used and in the third technique, a single electron beam was used. The comparative analyses between the three techniques were performed by comparing the boost PTV- dose volume histograms (DVHs), the ipsilateral breast (right breast) DVHs, the ipsilateral lung (right lung) DVHs and the heart DVHs of the three techniques for each patient. Furthermore the dose that covering 100% , 95% of the volume (D100% , D95%) and the volume covered by 95% of the dose (V95%)of  the boost PTV of all techniques, were calculated for each patient to investigate the dose coverage of the target.Results showed that there were variations of the dose received by tumor bed, right breast and OARs depending on the technique used and the target location and size. A decrease of D100% than 90% of the prescribed dose was observed with the 3rd technique for patients 8, 9 and 10, and was observed with the 2nd technique for patient 5. A reduction of right breast dose was observed when the 3rd technique was use in comparison with the 1st and the 2nd techniques for patients 1, 2, 3, 4, 6 and 8.  Also reduction of right breast was observed when the 2nd technique used in comparison with 1st technique. An increase of lung dose was observed with the 3rd technique for patients 1, 2, 5 and 6, also was observed with 2nd technique in patient 3, 5 and 7. A decrease of lung dose was observed with the 1st technique for patients 2, 4, 5, 6, 7, 8 and 9An individualized treatment, several plans using different irradiation techniques should be developed for each patient individually to reach the best boost PTV dose coverage with minimal OARs’ dose. 

NCS Report 2: Code of practice for the dosimetry of high-energy photon beams

1986 ◽  
Author(s):  
B.J. Mijnheer ◽  
A.H.L. Aalbers ◽  
J.J.M. Van Gasteren ◽  
A.G. Visser ◽  
F.W. Wittkämper
Keyword(s):  
High Energy ◽  
High Energy Photon ◽  
Photon Beams ◽  
Energy Photon ◽  
Code Of Practice

scholarly journals Relevance of Combined Electron and Photon Beams in Radiotherapy of Head and Neck Cancers in the Era of Intensity-Modulated Radiotherapy

2020 ◽  
Author(s):  
Vinod Pandey ◽  
K. C. Pandey ◽  
N. K. Pant ◽  
L. P. Verma
Keyword(s):  
Head And Neck ◽  
Electron Beams ◽  
External Beam Radiotherapy ◽  
Intensity Modulated Radiotherapy ◽  
Modern Technology ◽  
Head And Neck Cancers ◽  
Photon Beams ◽  
Average Percentage ◽  
Intensity Modulated ◽  
Electron And Photon

Abstract Introduction External beam radiotherapy (EBRT) for head and neck (H&N) cancers continues to be delivered using varied technologies, ranging from the old two-dimensional conventional radiotherapy (2DRT) techniques to the modern three-dimensional conformal radiotherapy (3DCRT), intensity-modulated radiotherapy (IMRT), and volumetric modulated arc therapy (VMAT) in different centers in India. Due to limitations of spinal cord tolerance, electron and photon beams are combined in 2DRT and 3DCRT techniques for treating nodal volume of the H&N cases. However, many centers having modern technology practice IMRT/VMAT in place of electron beams. The purpose of this study is to analyze the role of combined electron and photon beams in radiotherapy of H&N cancers and its relevance in the modern era of IMRT/VMAT. Materials and Methods Data were collected through a survey conducted on cancer centers in India where radiotherapy is being given by 2DRT, 3DCRT, and IMR/VMAT for the treatment of head and neck cancers. Results The mean percentage of H&N (H&N) cases among all cases were 39.2% (standard deviation [SD]: 14.22), out of which 16.63% (SD: 20.83) were treated with a combination of photon and electron beams and 49.73% (SD: 37.41) were treated with IMRT/VMAT. The average percentage of H&N cases of government institutes was 38.39% (SD: 14.11) and that of private institutes was 40.14% (SD: 14.11). Patients treated with photon and electron combination and IMRT/VMAT were 22.19% (SD: 11.24) and 24.05% (SD: 23.99), respectively, in government institutes, and 10.29% (SD: 11.24) and 79.09% (SD: 26.75) in private institutes. Conclusion As per this study, we conclude that despite the availability of IMRT/VMAT, a combination of electron and photon beams is still relevant in India. Since a large proportion of the patients are still treated with the electron and photon combination, it is imperative that further studies on field–junction dosimetry should be conducted to ensure accurate dose delivery.

Optimization of combined electron and photon beams for breast cancer

2004 ◽  
Vol 49 (10) ◽  
pp. 1973-1989 ◽  
Author(s):  
W Xiong ◽  
J Li ◽  
L Chen ◽  
R A Price ◽  
G Freedman ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Photon Beams ◽  
Electron And Photon

Dosimetry of High-Energy Photon Beams Based on Standards of Absorbed Dose to Water: Abstract

2001 ◽  
Vol 1 (1) ◽  
pp. 8-8 ◽  
Author(s):  
K. Hohlfeld ◽  
P. Andreo ◽  
O. Mattsson ◽  
J. P. Simoen
Keyword(s):  
Reference Conditions ◽  
International Comparisons ◽  
Absorbed Dose ◽  
High Energy ◽  
National Standards ◽  
Photon Radiation ◽  
Photon Beams ◽  
Radiation Induced ◽  
Absorbed Dose To Water ◽  
Primary Standards

This report examines the methods by which absorbed dose to water can be determined for photon radiations with maximum energies from approximately 1 MeV to 50 MeV, the beam qualities most commonly used for radiation therapy. The report is primarily concerned with methods of measurement for photon radiation, but many aspects are also relevant to the dosimetry of other therapeutic beams (high-energy electrons, protons, etc.). It deals with methods that are sufficiently precise and well established to be incorporated into the dosimetric measurement chain as primary standards (i.e., methods based on ionisation, radiation-induced chemical changes, and calorimetry using either graphite or water). The report discusses the primary dose standards used in several national standards laboratories and reviews the international comparisons that have been made. The report also describes the reference conditions that are suitable for establishing primary standards and provides a formalism for determining absorbed dose, including a discussion of correction factors needed under conditions other than those used to calibrate an instrument at the standards laboratory.

scholarly journals EP-1754 High-resolution assessment of dose calculations in small MV photon beams on and off central axis

2019 ◽  
Vol 133 ◽  
pp. S946-S947
Author(s):  
G. Biasi ◽  
N. Hardcastle ◽  
M. Petasecca ◽  
S. Guatelli ◽  
V.L. Perevertaylo ◽  
...  
Keyword(s):  
High Resolution ◽  
Central Axis ◽  
Dose Calculations ◽  
Photon Beams
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