Consistency check of photon beam physical data after recommissioning process

Kadman, B; Chawapun, Nisa; Ua-apisitwong, Supoj; Asakit, Tussawan; Chumpu, N; Rueansri, Jumneanphan

doi:10.1088/1742-6596/694/1/012023

Cited by 3 publications

(2 citation statements)

References 1 publication

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“…The Monte Carlo simulation validation of Varian Clinac 2100 is a subject of one of our previous scientific publications [21]. It is more accurate by approximately 99 % for PDD and dose profile in comparison with previous studies [22]. The primary electron source above the target is monoenergetic with the energy of 6.52 MeV, the radial spread is Gaussian with the full width at half maximum (FWHM) of 1.4 mm, and the mean angle spread is 1 °.…”

Section: Resultsmentioning

confidence: 99%

Monte Carlo-based analysis of the photon beam fluence with air gap thickness between Linac head exit window and patient’s skin in radiotherapy treatments

Bencheikh¹,

Maghnouj²,

Tajmouati³

2020

Nucl. Phys. At. Energy

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Linear accelerators (Linac) are used in radiation therapy treatment and its technology improvement ensures high dosimetry quality that should be conserved for high radiotherapy efficiency. However, does the air gap between the exit window of Linac head and patient’s skin alters the physical properties of the photon beam? The objective of this study is to assess the physical properties changes of photon beam fluence according to air gap thickness under the Linac head. The air gap under the Linac head is the last material in the photon beam path; it induces alterations in the beam quality before reaching the patient’s skin. The Varian Clinac 2100 head and the air gap up to the phantom surface are modelled using Monte Carlo BEAMnrc code; the nominal beam energy is 6 MV. The BEAMDP code is used to extract the photon fluence. The photon beam fluence is affected by the air gap under Linac head and decreases by six times due to the photon beam attenuation with air gap thickness; in addition to increasing of beam contamination by scattered photons and electrons. Thus, the air gap induces the beam quality deterioration which is evaluated in terms of photon fluence with air gap thickness. To remove the particles contaminations and conserve integrally the photon beam quality, the number of the photon interactions with air atoms should be as low as possible under Linac head up to patient’s skin and ensure a higher quality of the radiotherapy treatment of deep tumour.

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Section: Resultsmentioning

confidence: 99%

Monte Carlo-based analysis of the photon beam fluence with air gap thickness between Linac head exit window and patient’s skin in radiotherapy treatments

Bencheikh¹,

Maghnouj²,

Tajmouati³

2020

Nucl. Phys. At. Energy

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“…The relationship between dosage on the main axis and its outside is very complicated, depending on radiation energy, SSD, collimator properties, field size, the angle between the main axis of the radiation beam and the surface of the medium [8], block that is forming field, source size, penumbra [9], symmetry, uniformity of radiation beam, flattening filter [10]. As a result of the numerous factors that influence dosage, not all of the doses outside the central axis can be expressed by a mathematical formula.…”

Section: Profile Dosementioning

confidence: 99%

Monte Carlo Simulation-Based BEAMnrc Code of a 6 MV Photon Beam Produced by a Linear Accelerator (LINAC)

Sapundani

Ekawati²,

Wibowo

2021

Atom Indo.

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In radiotherapy, high energy ionizing radiation, such as X-rays, gamma rays and electron beams, is used. The dose in the tissue is often approached with the dose in the medium of the body which is 80 % of human soft tissue. It is often difficult to determine the dose because the interaction of materials in a medium is very random. Measurement is also quite difficult because there are almost no detectors that are tissue equivalent. Measurement using an ion chamber requires a lot of correction to obtain a dose in the tissue, which is done using phantom and not directly in humans. This research aimed to compare the absorbed dose between modelling using Monte Carlo simulation and experiments. The simulation of dose distribution produced by a 6 MV medical linear accelerator has been performed using BEAMnrc code running on Linux-based 2 processor system arranged in parallel. BEAMnrc was used to model and simulate the linac head with an SSD of 100 cm and Field size of 10x10 cm 2 . A phase-space file is obtained as input to a DOSXYnrc code to produce Percent Depth Dose (PDD) in water and polymethyl methacrylate (PMMA) phantoms. New particles formed (electrons: 0.2 %, photon: 0.17 %; and positron: 0.08 %) were far from the contamination threshold of 2 %. The range of the correction factor of the depth of a maximum dose compared to the experimental data was 0.04-0.15.

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Analysis of stabilization of photon beam softening with off-axis distance for filtration system enhancement to increase dosimetry in radiotherapy

Bencheikh¹,

Maghnouj²,

Tajmouati³

et al. 2020

Journal of King Saud University - Science

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Consistency check of photon beam physical data after recommissioning process

Cited by 3 publications

References 1 publication

Monte Carlo-based analysis of the photon beam fluence with air gap thickness between Linac head exit window and patient’s skin in radiotherapy treatments

Monte Carlo-based analysis of the photon beam fluence with air gap thickness between Linac head exit window and patient’s skin in radiotherapy treatments

Monte Carlo Simulation-Based BEAMnrc Code of a 6 MV Photon Beam Produced by a Linear Accelerator (LINAC)

Analysis of stabilization of photon beam softening with off-axis distance for filtration system enhancement to increase dosimetry in radiotherapy

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