scholarly journals Dosimetric characterization of medical linear accelerator Photon and Electron beams for the treatment accuracy of cancer patients

2021 ◽  
Vol 3 (1) ◽  
pp. 041-059
Author(s):  
Motiur Rahman ◽  
M Shamsuzzaman ◽  
Manoshi Sarker ◽  
Abdul Jobber ◽  
Mohsin Mia ◽  
...  
Keyword(s):  
Linear Accelerator ◽  
Planning Process ◽  
Electron Beams ◽  
Small Deviation ◽  
Beam Profile ◽  
Field Size ◽  
Photon Beams ◽  
Depth Dose ◽  
Medical Linear Accelerator

In radiotherapy treatment planning process, quality assessment (QA) is indispensable for achieving accuracy and avoidance of treatment errors. In this perspective, present study focused on the Photon and Electron beams characterization of a medical linear accelerator (LINAC) to ascertain dosimetric QA in Absolute and Reference dosimetry. In this connection, the beam outputs were investigated in terms of Dmax and Dw,max (dose at depth dmax) in absolute dosimetry for Photon and Electron beams, respectively. In accordance with the measured Dmax and Dw,max parameters, Photon and Electron beam outputs were standardized to ensure standard output of 1 cGy/MU. In reference dosimetry, the parametric evaluation was performed for dosimetric QA in terms of percent depth dose (PDD), beam profile flatness and symmetry, output factors: Scp, Sc, Sp with varying field size (FS) ranging from 4´4 cm2 to 40´40 cm2 normalized at FS 10´10 cm2 for the 6 MV and 10 MV Photon beams. The measured PDDs at 10 cm depth (D10) were found to be 66.8% and 73.6% for 6 MV and 10 MV Photon beams, respectively, with significantly small deviation of 1% and 0.8% in comparison with an international PDD protocol of British Journal of Radiology-25 (BJR -25). In the case of Electron beams characterization, PDD was verified with 10´10 cm2 cone/applicator, beam profile flatness and symmetry were analyzed at the field sizes ranging from 6´6 cm2 to 25´25 cm2 normalized at 10´10 cm2 cone/applicator, and Electron cone ratios were investigated for a given cone/applicator relative to the 15´15 cm2 one for the 6, 9, 12, 15 MeV Electron energies. The PDDs of all the Electron beams revealed reasonable consistency with manufacturer’s estimations of 90%, 80%, and 50% PDDs at various depths of ionization.

scholarly journals Improving Clinical dosimetric Accuracy of cancer treatment using a special quality of Electron and Photon Beam

2021 ◽  
Vol 5 (3) ◽  
Author(s):  
Ayesha Ikhlaq ◽  
Saeed Ahmad Buzdar ◽  
Muhammad Usman Mustafa ◽  
Sana Salahuddin ◽  
Mehr-Un-Nisa ◽  
...  
Keyword(s):  
Radiation Therapy ◽  
Electron Beam ◽  
Electron Beams ◽  
Photon Beam ◽  
Field Size ◽  
External Beam Radiation ◽  
Photon Beams ◽  
Depth Dose ◽  
Electron And Photon

In external beam radiation therapy, electron and photon beams have extraordinary characteristics in the treatment of cancer. The electron and photon beam characteristic are essential to study before calibration of machine. This study focused on the dosimetric characteristics of different energies of electron beams for different field size. The basic objective of this work is, to calculate dosimetric parameters and characteristics of electron beam, specially depth dose characteristics along central axis. In this work, 6 MeV, 9 MeV, 12 MeV, 15 MeV and 18 MeV of electron beam and 6 MV and 15 MV of photon beam with different field size is used. Characteristics of depth dose of electron and photon beam in water have analyzed to provide better quality of radiation therapy treatment planning. The different beam characteristics are due to different interactions that occurs between electron beams giving them a definite range whereas photon beams are attenuated leading to dose deposition and much larger range with no definite end. Depth dose characteristics of electron and photon beams do not show same characteristics as interaction of beam with matter depends on the quality of beam. Attenuation and penetration factors change with changing dosimetric parameters. Complete analysis of dosimetric characteristics of electron and photon beam help to choose more accurate beam for the treatment of cancer. This work will help to increase accuracy in treatment of cancer with radiotherapy.

scholarly journals Studies of Dosimetry Protocols for Accelerated Photons and Electrons Delivered from Medical Linear Accelerator

2021 ◽  
Keyword(s):  
Comparative Study ◽  
Linear Accelerator ◽  
Electron Beams ◽  
Absorbed Dose ◽  
Photon Beam ◽  
Photon Beams ◽  
Medical Linear Accelerator ◽  
The Comparative Study ◽  
Electron And Photon ◽  
Medical Linac

We focus on the comparative study of dosimetry protocols in radiotherapy for accelerated photon and electron delivered from medical linear accelerator (LINAC). In this study, a comparison between the protocols (TRS 398, DIN 6800-2 and TG 51) for both the electron and photon delivered from Clinac 2300CD and Clinac DHX 3186 were performed. We used photon beams with energies of 6 and 15 MV and electron beams of 4, 6, 9, 12, 15 and 18 MeV for both Medical Linac. In case of Clinac the maximum deviations for the relative dose at Dmax for the photon beam (15 MV) among the protocols was observed to be 1.18% between TRS-398 and TG-51, 1.56% between TG-51 and DIN 6800-2; and 0.41% between TRS-398 and DIN 6800-2. Conversely, these deviations were 3.67% between TRS-398 and TG-51, 3.92% between TG-51 and DIN 6800-2 for 4 MeV and 0.95% between TRS-398 and DIN 6800-2 in the case of Clinac 2300 CD for the PTW Markus and Exradin A10. For the measurement of the maximum absorbed dose depth to water using three protocols, the maximum deviations were observed between TRS 398 and TG-51 as well as TG51 and DIN 6800-2.

scholarly journals Grid Monte Carlo Simulation of a Medical Linear Accelerator

2018 ◽  
Vol 3 (12) ◽  
pp. 40-43 ◽  
Author(s):  
Didi Samir ◽  
Mustapha Zerfaoui ◽  
Abdelilah Moussa ◽  
Yassine Benkhouya ◽  
Mehdi El Ouartiti
Keyword(s):  
Monte Carlo ◽  
Linear Accelerator ◽  
Field Size ◽  
Dose Profile ◽  
Depth Dose ◽  
Grid Simulation ◽  
Medical Linear Accelerator ◽  
Measured Dose ◽  
Better Than ◽  
Good Agreement

A full grid simulation of the head of an Elekta Synergy Platform medical linear accelerator is performed using the Geant4 Monte Carlo platform. The simulation includes all components of the accelerator head and a homogeneous water phantom. Results in terms of depth doses and lateral dose profiles are presented for 6 MV photon beam with the 10x10 cm2 reference field size at 100 cm distance from the source. Overall, a good agreement with the measured dose data is achieved with a precision better than 0.93% and 2.63% for the depth dose profile and lateral dose profiles respectively.

Dosimetric comparison of photon beam profile characteristics for different treatment parameters

2017 ◽  
Vol 16 (4) ◽  
pp. 444-450 ◽  
Author(s):  
Qurat-ul-ain Shamsi ◽  
Maria Atiq ◽  
Atia Atiq ◽  
Saeed Ahmad Buzdar ◽  
Khalid Iqbal ◽  
...  
Keyword(s):  
Linear Accelerator ◽  
Radiation Treatment ◽  
Beam Profile ◽  
Photon Beam ◽  
Field Size ◽  
Photon Beams ◽  
Linear Accelerators ◽  
Water Phantom ◽  
Treatment Plans ◽  
Profile Characteristics

AbstractPurposeTo deliver radiation doses with higher accuracy, radiation treatment through megavoltage photon beams from linear accelerators, is accepted widely for treating malignancies. Before calibrating the linear accelerators, it is essential to make a complete analysis of all photon beam profile parameters. The main objective of this exploration was to investigate the 6 and 15 MV photon beam profile characteristics to improve the accuracy of radiation treatment plans.MethodsIn this exploration, treatment parameters like depth, field size and beam energy were varied to observe their effect on dosimetric characteristics of beam profiles in a water phantom, generated by linear accelerator Varian Clinac.ResultsThe results revealed thatDmaxandDmindecreased with increasing depth but increased with increasing field sizes. Both left and right penumbras increased with increasing depth, field size and energy. Homogeneity increased with field size but decreased with depth. Symmetry had no dependence on depth, energy and field size.ConclusionAll the characteristics of photon beam dosimetry were analysed and the characteristics like homogeneity and symmetry measured by an ion chamber in a water phantom came within clinically acceptable level of 3 and 103%, respectively, thus fulfilled the requirements of standard linear accelerator specifications. This exploration can be extended to the determination of beam profile characteristics of electron and photon beams of other energies at various depths and field sizes for designing optimum treatment plans.

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

2018 ◽  
Vol 18 (03) ◽  
pp. 280-284 ◽  
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.

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

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.

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

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).

scholarly journals Beam characterization of 10-MV photon beam from medical linear accelerator without flattening filter

2017 ◽  
Vol 42 (2) ◽  
pp. 65
Author(s):  
Tomohiro Shimozato ◽  
Yuichi Aoyama ◽  
Takuma Matsunaga ◽  
Katsuyoshi Tabushi
Keyword(s):  
Linear Accelerator ◽  
Photon Beam ◽  
Medical Linear Accelerator ◽  
Beam Characterization ◽  
Flattening Filter

scholarly journals Commissioning Measurements of Electron Beam Using Montecarlo Algorithm on Truebeam STx® and Compariaon with Clinac iX Linear Accelerator

2021 ◽  
Vol 229 ◽  
pp. 01041
Author(s):  
Kamal Saidi ◽  
Redouane El Baydaoui ◽  
Hanae El Gouach ◽  
Othmane Kaanouch ◽  
Mohamed Reda Mesradi
Keyword(s):  
Electron Beam ◽  
Electron Beams ◽  
Measured Data ◽  
University Hospital ◽  
Field Size ◽  
Large Field ◽  
Water Phantom ◽  
Depth Dose ◽  
International University ◽  
The Absolute

TrueBeam STx latest generation linear accelerators (linacs) installed at Sheikh Khalifa International University Hospital in Casablanca, Morocco. The aim of this is to present and compare the result of the Electron commissioning measurement on TrueBeam Stx and clinac iX installed at Sheikh Khalifa International University Hospital in Casablanca, Morocco. A compariaon of eMC calculations and measurements for TrueBeam Stx were evaluated. Dosimetric parameters are systematically measured using a large water phantom 3D scanning system MP3 Water Phantom (PTW, Freiburg, Germany). The data of the electron beams commissioning including depth dose curves for each applicator, depth dose curves without applicator and the profile in air for a large field size 40x 40cm2, and the Absolute Dose (cGy/MU) for each applicator. All the data were examined and compared for five electron beams (E6MeV, E9MeV, E12MeV, E16MeV and E20MeV) of Varian’s TrueBeam STx and Clinac iX machines. A comparison, between measurement PDDs and calculated by the Eclipse electron Monte Carlo (eMC) algorithm were performed to validate Truebeam Stx commissioning. All this measurements were performed with a Roos and Markus plane parallel chamber. Our measured data indicated that electron beam PDDs from the TrueBeam Stx machine are well matched to those from our Varian Clinac iX machine. Significant differences between TrueBeam and Clinac iX were found in in‐air profiles and open field output. Maximum depth dose for the TrueBeam Stx and Clinac iX for the following energies (6, 9, 12, 16, 20 MeV) are respectively (1.15; 1.89; 2.6; 3.1; and 2.35) and (1.24; 1.95; 2.70; 2.99 and 2.4cm). For the TrueBeam Stx and Clinac iX the quality index R50 for applicator 15x15 cm2 are in the tolerance intervals. Surface dose increases by increasing energy for both machines. The Absolute Dose (cGy/MU) calibrated for both machine in Dmax at 1cGy/MU for the reference field size cone 15x15 cm2. Bremsstrahlung tail Rp per energy levels as follows for the TrueBeam Stx : 6 MeV – 2.85 cm, 9 MeV – 4.28 cm, 12 MeV – 5.97 cm, 16 MeV – 7.88 cm and 20 MeV – 9.86 cm. and for the Clinac iX : 6 MeV – 2.86 cm, 9 MeV – 4.32 cm, 12 MeV – 5.96 cm, 16 MeV – 7.93 cm and 20 MeV – 10.08 cm. A good agreement between modeled and measured data is observed.

Khảo sát một số đặc tính bức xạ của buồng ion hóa CC13 và diode bán dẫn razor đối với các chùm photon kích thước nhỏ trên máy gia tốc tuyến tính xạ trị Clinac IX

2020 ◽  
Author(s):  
Tu Vu Ngoc
Keyword(s):  
Radiation Field ◽  
Dose Response ◽  
Dose Distribution ◽  
Ionization Chamber ◽  
Field Size ◽  
Photon Beams ◽  
Silicon Diode ◽  
Depth Dose ◽  
The Difference

Purpose: Compare percent depth dose (PDD) and off-center ratio (OCR) measured by the CC13 ionization chamber and the RAZOR silicon diode in small photon beams. Method and Materials: Some dosimetric characteristics, such as PDD, OCR, penumbra and radiation field size, were considered in this study for 2x2, 3x3, and 4x4 cm2 field sizes. We used the CC13 ionization chamber and the RAZOR silicon diode to measure dose distribution with depth along the axis and off-center of the beam. From the results obtained, the team investigated the differences in radiation parameters measured by the two types of probes above. Results: There are significant differences in the radiation parameters investigated for the CC13 ionization chamber and the RAZOR silicon diode, especially the width of penumbra. For PDD curves, the difference is less than 5% from dmax to 30 cm, however the difference becomes greater in the build-up region, which reaches to 33% at the water phatom surface. The width of penumbra measured by CC13 is always larger than that of RAZOR, the ratio of the penumbra width between two detectors is 1.8 and 1.3 for energies of 6 MV and 15 MV, respectively. Conclusion: The RAZOR silicon diode has better dose response than the CC13 ionization chamber for measuring the PDD and the OCR in small photon beams.

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