Percentage depth dose measurement in high energy photons and electrons by using the Al2O3 optically stimulated luminescent (OSL) dosimeter

The purpose of this study is to measure doses delivered at different depths in water phantom at vertical position in comparison with the actual planning in order to verify the dose delivered to the tumor in addition to the measurement of the effect penumbra dose to assess the dose leaking to the healthy soft tissue. Percentage depth dose (PDD) values was measured at field sizes (5Ã—5,10Ã—10,15Ã—15, and 20Ã—20) cm2, and the depth dose was measured between (0-16) cm deep at 4cm intervals, for both energies 6 MeV and 10 MeV X-ray beam. Other readings were taken at different distances 1cm and 2cm outside of the actual beam in orthogonal directions at depth of 4 cm. These measurements were designed to measure the penumbra dose produced outside the central beam. Results show that the high similarity between water phantom and actual tissue for this reason water is taken as phantom for Quality Assurance (QA) and calculation the depth dose. The similar results may appear strange as the actual planning depth dose is taken in the chest wall where there is bone and soft tissue. The increase in the field size, increases the percentage of surface dose, this could be caused by an increase in the amount of scattering in the larger fields. There is almost no difference in depth dose between homogenous and non homogenous planning also similar to the water phantom. Because of higher photon energy 6MeV and 10MeV the bone has no influence in absorption from the soft tissue. A slight change in the depth dose with increase in the field size may be caused by the scattered radiation.

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Central Axis Percentage Depth-Dose for High Energy Electrons

Radiation Research ◽

10.2307/3573970 ◽

1974 ◽

Vol 60 (2) ◽

pp. 342 ◽

Cited By ~ 5

Author(s):

J. M. Pacyniak ◽

A. Pagnamenta

Keyword(s):

High Energy ◽

Central Axis ◽

Percentage Depth Dose ◽

Depth Dose ◽

High Energy Electrons

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Percentage depth dose fragmentation for investigating and assessing the photon beam dosimetry quality

Journal of Radiotherapy in Practice ◽

10.1017/s1460396918000687 ◽

2018 ◽

Vol 18 (03) ◽

pp. 280-284 ◽

Cited By ~ 4

Author(s):

Mohamed Bencheikh ◽

Abdelmajid Maghnouj ◽

Jaouad Tajmouati

Keyword(s):

Exponential Decay ◽

Target Volume ◽

Photon Beam ◽

Field Size ◽

Photon Beams ◽

Energy Agency ◽

Percentage Depth Dose ◽

Depth Dose ◽

Beam Dosimetry

AbstractAimThe purpose of this study is to introduce a new approach to assess the dosimetry quality of photon beam with energy and irradiation field size. This approach is based on percentage depth dose (PDD) fragmentation for investigating the dosimetry quality.Materials and methodsFor the investigation of the dosimetry quality of 6 and 18 MV photon beams, we have proceeded to fragment the PDD at different field sizes. This approach checks the overall PDD and is not restricted to the exponential decay regions, as per the International Atomic Energy Agency Technical Reports Series No 398 and the American Association of Physicist in Medicine Task Group 51 recommendations.Results and discussionThe 6 MV photon beam deposited more energy in the target volume than the 18 MV photon beam. The dose delivered by the 6 MV beam is greater by a factor of 1·5 than that delivered by the 18 MV beam in the build-up region and the dose delivered by the 6 MV beam is greater by a factor of 2·6 than that delivered by the 18 MV beam in the electronic equilibrium and the exponential decay regions.ConclusionThe dose measured at different points of the beam is higher for 6 MV than for 18 MV photon beam. Therefore, the 6 MV beam is more dosimetrically efficient than the 18 MV beam. Using the proposed approach, we can assess the dosimetry quality by taking into account overall PDD not only in the exponential decay region but also in the field.

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Dosimetric Characterization of Small Radiotherapy Electron Beams Collimated by Circular Applicators with the New Microsilicon Detector

Applied Sciences ◽

10.3390/app12020600 ◽

2022 ◽

Vol 12 (2) ◽

pp. 600

Author(s):

Serenella Russo ◽

Silvia Bettarini ◽

Barbara Grilli Leonulli ◽

Marco Esposito ◽

Paolo Alpi ◽

...

Keyword(s):

Radiation Therapy ◽

Electron Beams ◽

High Energy ◽

Field Size ◽

The Novel ◽

Linear Accelerators ◽

Depth Dose ◽

Dosimetric Data ◽

Output Factors ◽

Dose Measurements

High-energy small electron beams, generated by linear accelerators, are used for radiotherapy of localized superficial tumours. The aim of the present study is to assess the dosimetric performance under small radiation therapy electron beams of the novel PTW microSilicon detector compared to other available dosimeters. Relative dose measurements of circular fields with 20, 30, 40, and 50 mm aperture diameters were performed for electron beams generated by an Elekta Synergy linac, with energy between 4 and 12 MeV. Percentage depth dose, transverse profiles, and output factors, normalized to the 10 × 10 cm2 reference field, were measured. All dosimetric data were collected in a PTW MP3 motorized water phantom, at SSD of 100 cm, by using the novel PTW microSilicon detector. The PTW diode E and the PTW microDiamond were also used in all beam apertures for benchmarking. Data for the biggest field size were also measured by the PTW Advanced Markus ionization chamber. Measurements performed by the microSilicon are in good agreement with the reference values for all the tubular applicators and beam energies within the stated uncertainties. This confirms the reliability of the microSilicon detector for relative dosimetry of small radiation therapy electron beams collimated by circular applicators.

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The effects of cutouts on output, mean energy and percentage depth dose of 12 and 14 MeV electrons

Journal of Medical Physics ◽

10.4103/0971-6203.89970 ◽

2011 ◽

Vol 36 (4) ◽

pp. 213 ◽

Cited By ~ 7

Author(s):

Navid Khaledy ◽

Dariush Sardari ◽

Azim Arbabi

Keyword(s):

Percentage Depth Dose ◽

Depth Dose

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Applications and benefits of using gradient percentage depth dose instead of percentage depth dose for electron and photon beams in radiotherapy

Polish Journal of Medical Physics and Engineering ◽

10.2478/pjmpe-2021-0004 ◽

2021 ◽

Vol 27 (1) ◽

pp. 25-29

Author(s):

Labinot Kastrati ◽

Gezim Hodolli ◽

Sehad Kadiri ◽

Elvin Demirel ◽

Lutfi Istrefi ◽

...

Keyword(s):

Electron Beams ◽

Published Data ◽

Photon Beams ◽

Data Set ◽

Percentage Depth Dose ◽

Depth Dose ◽

Electron And Photon

Abstract Introduction: The aim of this study is to analyze the gradient of percentage depth dose for photon and electron beams of LINACs and to simplify the data set. Materials and Methods: Dosimetry measurements were performed in accordance with Technical Reports Series No. 398 IAEA. Results and discussion: The gradient of percentage depth dose was calculated and compared with the available published data. Conclusion: Instead of percentage depth dose for increasing and decreasing parts, the findings suggest using only two numbers for specific gradient of dose, separately. In this way, they can replace the whole set of the percentage depth dose (PDD).

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