1
|
Geraily G, Ameri A, Mahmoudi A, Moafee M, Teymouri J. Assessing the Risk of Secondary Cancer Induction in Radiosensitive Organs During Trigeminal Neuralgia Treatment With Gamma Knife Radiosurgery: Impact of Extracranial Dose. Dose Response 2023; 21:15593258231210432. [PMID: 37900619 PMCID: PMC10605703 DOI: 10.1177/15593258231210432] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 10/11/2023] [Indexed: 10/31/2023] Open
Abstract
Purpose Gamma knife radiosurgery (GKRS) delivers high-dose external radiation to a small intracranial lesion. However, scattering and leaked radiation can deposit a portion of the dose outside the radiation field, which may pose a risk to radiation-sensitive patients, such as pregnant women. Trigeminal Neuralgia (TN) is treated with one of the highest GKRS doses (80-90 Gy). This study aimed to estimate the risk of secondary cancer induction in the uterus, ovaries, thyroid gland, and eyes of TN patients undergoing GKRS. Methods Radiation doses to the uterus, ovary, eyes, and thyroid gland were measured for 25 female TN patients, with a mean age of 35 years, utilizing Thermo Luminescent Dosimeters (TLD). Results The mean absorbed dose for the uterus, ovary, thyroid gland, and eyes were .63 ± .24, .471 ± .2, 8.26 ± 1.01, and 10.64 ± 1.08 cGy, respectively. Lifetime Attributable Risk (LAR) has been calculated using BEIR VII (2006) method. LAR for the uterus, ovary, and thyroid gland was 1, 2, and 23, respectively. Conclusion The results of this study and its comparison with standard values demonstrate that on average, mean doses to mentioned organs were smaller than their tolerance doses, and there is no limitation to treating patients suffering from TN by GK.
Collapse
Affiliation(s)
- Ghazale Geraily
- Department of Medical Physics and Biomedical Engineering, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
- Radiation Oncology Research Center, Cancer Institute, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran
| | - Ali Ameri
- Department of Medical Physics and Biomedical Engineering, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
- Radiation Oncology Research Center, Cancer Institute, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran
| | - Atefeh Mahmoudi
- Department of Medical Physics and Biomedical Engineering, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Mohadese Moafee
- Department of Medical Physics and Biomedical Engineering, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Javad Teymouri
- Department of Radiation Oncology, Iran Gamma Knife Centre, Tehran, Iran
| |
Collapse
|
2
|
Saini A, Pandey VP, Singh A, Kumar P. Evaluating impact of medium variation on dose calculated through planning system in a low cost in-house phantom. Biomed Phys Eng Express 2022; 8. [PMID: 35144251 DOI: 10.1088/2057-1976/ac53bc] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 02/10/2022] [Indexed: 11/12/2022]
Abstract
Purpose:In radiotherapy, accuracy in dose estimation of dose calculation methods is critical. The influence of deformity on radiation dose calculations derived by planning system is evaluated in present study. The goal of study was to create a low-cost inhomogeneous phantom for measuring absorbed dose using an Ionisation chamber and Gafchromic film, which was validated using treatment planning system (TPS) dose outcome.Methods and Materials:The central axis dose calculations were computed using Pencil Beam Convolution algorithm (PBC), Collapsed Cone Convolution (CCC) and Monte Carlo (MC) algorithm in the Monaco treatment planning system using an In-house phantom (20x20x20cm3) made up of acrylic sheet containing water and inhomogeneous material wooden powder equivalent to lung. Phantom was scanned in Computed Tomography (CT) scanner and image set was sent to the planning workstation. The depth dose evaluations were performed using ionization chamber and Gafchromic film with same beam settings and monitor units in every setup. Following that, the calculated doses obtained from TPS and measured depth doses were compared.Results:The results was reported for photon energies 6MV, 10MV, 15MV, 6FFF and 10FFF at varying field sizes of 4X4 cm2, 5x5 cm2, 10x10 cm2, and 15x15 cm2. MC maximum dose variation predicted was 2.06% in 15MV of measured chamber dose and -2.06% of measured gafchromic film dose in 6MVFFF. CCC maximum dose variation predicted was 2.68% of measured chamber dose in 6MV and 3.31% of measured gafchromic film dose in 6MV whereas PB maximum dose variation predicted was -5.94% in 15MV of measured chamber dose and -11.6% of measured gafchromic film dose in 6MVFFF.Conclusion:Low-cost in-house phantoms can be utilised to assess point and planar doses during patient-specific quality assurance in centres that don't have accessibility to phantoms due to the high cost of commercially available tools.
Collapse
Affiliation(s)
- Amit Saini
- Chitkara Institute of Engineering and Technology, Chitkara University, Rajpura, Punjab, 140401, INDIA
| | - V P Pandey
- Department of Medical Physics, Hind Institute of Medical Sciences, Safedabad, Barabanki, Lucknow, Uttar Pradesh, 225003, INDIA
| | - Avtar Singh
- Chitkara Institute of Engineering and Technology, Chitkara University, Rajpura, Punjab, 140401, INDIA
| | - Pankaj Kumar
- Chitkara University, Centre for Liquid Crystal Research, Chitkara University Research and Innovation Network, Rajpura, Punjab, 140401, INDIA
| |
Collapse
|
3
|
Dunn L, Godwin G, Hellyer J, Xu X. A method for time‐independent film dosimetry: Can we obtain accurate patient‐specific QA results at any time postirradiation? J Appl Clin Med Phys 2022; 23:e13534. [PMID: 35049118 PMCID: PMC8906213 DOI: 10.1002/acm2.13534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Revised: 12/15/2021] [Accepted: 12/30/2021] [Indexed: 11/09/2022] Open
Affiliation(s)
- Leon Dunn
- St Vincent's GenesisCare Centre for radiation oncology St Vincent's Hospital Basement Level Building C, 41 Victoria Parade, Fitzroy VIC 3065 Melbourne Victoria 3065 Australia
| | - Guy Godwin
- Redland Icon Cancer Care Bayside Business Park, 16/24 Weippin St, Cleveland QLD Brisbane Queensland 4163 Australia
| | - James Hellyer
- Macquarie University GenesisCare Centre for radiation oncology Hospital Building Suite 1, Level B2, 3 Technology Pl, Macquarie University NSW Sydney New South Wales 2109 Australia
| | - Xiaolei Xu
- St Vincent's GenesisCare Centre for radiation oncology St Vincent's Hospital Basement Level Building C, 41 Victoria Parade, Fitzroy VIC 3065 Melbourne Victoria 3065 Australia
| |
Collapse
|
4
|
Fahimi Monzari S, Geraily G, Aghili M, Toolee H. Evaluation of Dose Distribution in Optimized Stanford Total Skin Electron Therapy (TSET) Technique in Rando Anthropomorphic Phantom using EBT3 Gafchromatic Films. J Biomed Phys Eng 2021; 11:425-434. [PMID: 34458190 PMCID: PMC8385220 DOI: 10.31661/jbpe.v0i0.1035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 10/24/2018] [Indexed: 12/05/2022]
Abstract
Background: The Total Skin Electron Therapy (TSET) targets the whole of skin using 6 to 10 MeV electrons in large field size and large Source to Surface Distance (SSD).
Treatment in sleeping position leads to a better distribution of dose and patient comfort. Objective: This study aims to investigate the uniformity of absorbed dose in the sleeping Stanford technique on the Rando phantom using dosimetry. Material and Methods: It is an experimental study which was performed using 6 MeV electron irradiation produced by Varian accelerator in the AP and PA positions with gantry angles of 318/3, 0 and 41/5 degrees,
and RAO, LAO, RPO and LPO with 291/4 gantry angle and 45 degrees of collimator angle in the sleeping position. Results: The results show that the dose uniformity achieved in this technique is in the range of (100 ± 25%) and, the dose accuracy was 6%. Conclusion: Total Skin Electron Therapy (TSET) technique in sleeping position is very suitable for elderly and disabled patients, and meets the required dose uniformity.
Furthermore, the use of a flattening filter is recommended for the more dose distribution uniformity.
Collapse
Affiliation(s)
| | - Ghazale Geraily
- PhD, Department of Medical Physics, Tehran University of Medical Sciences, Tehran, Iran
| | - Mehdi Aghili
- MD, Oncology Specialist, Cancer Institute of Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Heydar Toolee
- PhD, Department of Anatomy, Tehran University of Medical Sciences, Tehran, Iran
| |
Collapse
|
5
|
Hasan N, Sham NFR, Karim MKA, Fuad SBSA, Hasani NAH, Omar E, Ibahim MJ. Development of custom lead shield and strainer for targeted irradiation for mice in the gamma cell chamber. Sci Rep 2021; 11:14559. [PMID: 34267293 PMCID: PMC8282798 DOI: 10.1038/s41598-021-93964-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 07/05/2021] [Indexed: 11/09/2022] Open
Abstract
We presented a development of a custom lead shield and mouse strainer for targeted irradiation from the gamma-cell chamber. This study was divided into two parts i.e., to (i) fabricate the shield and strainer from a lead (Pb) and (ii) optimize the irradiation to the mice-bearing tumour model with 2 and 8 Gy absorbed doses. The lead shielding was fabricated into a cuboid shape with a canal on the top and a hole on the vertical side for the beam path. Respective deliveries doses of 28 and 75 Gy from gamma-cell were used to achieve 2 and 8 Gy absorbed doses at the tumour sites.
Collapse
Affiliation(s)
- Nurhaslina Hasan
- Faculty of Medicine, Universiti Teknologi MARA, 47200, Sungai Buloh, Selangor, Malaysia
- Faculty of Dentistry, Universiti Teknologi MARA, 47200, Sungai Buloh, Selangor, Malaysia
| | | | | | | | | | - Effat Omar
- Faculty of Medicine, Universiti Teknologi MARA, 47200, Sungai Buloh, Selangor, Malaysia
| | - Mohammad Johari Ibahim
- Faculty of Medicine, Universiti Teknologi MARA, 47200, Sungai Buloh, Selangor, Malaysia.
| |
Collapse
|
6
|
Evaluation of the surface dose for total body irradiation (TBI) technique with parallel-opposed anterior posterior geometry. JOURNAL OF RADIOTHERAPY IN PRACTICE 2021. [DOI: 10.1017/s1460396921000121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Abstract
Aim:
Total body irradiation (TBI) is an external radiotherapy technique in which the whole body including the superficial regions is required to receive the therapeutic dose. The purpose of this study is to evaluate the received surface dose during TBI technique.
Methods and materials:
The anterior/posterior (AP/PA) TBI was implemented with 18-MV photon beam at 312-cm treatment distance for human-like phantom. The GAFCHROMIC-EBT3 films were used for superficial dose measurements.
Results and discussion:
The percentage of surface-absorbed dose relative to the prescription point for 8 points of measurements was between 102·78–121·48% and 104·51–127·43% at 5 and 10 mm depth, respectively. In the chest wall region due to the presence of lung blocks, the absorbed dose was below the acceptable level, so an electron boost was required to increase the chest wall absorbed dose.
Conclusions:
According to the results, the implemented technique was able to deliver sufficient dose to the shallow surface of phantom’s body.
Collapse
|
7
|
Hur BI, Jin SJ, Kim GR, Kwak JH, Kim YH, Lee SW, Sung SK. Validation of Gamma Knife Perfexion Dose Profile Distribution by a Modified Variable Ellipsoid Modeling Technique. J Korean Neurosurg Soc 2021; 64:13-22. [PMID: 33465847 PMCID: PMC7819799 DOI: 10.3340/jkns.2020.0186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 12/15/2020] [Indexed: 11/27/2022] Open
Abstract
OBJECTIVE High precision and accuracy are expected in gamma knife radiosurgery treatment. Because of the requirement of clinically applying complex radiation and dose gradients together with a rapid radiation decline, a dedicated quality assurance program is required to maintain the radiation dosimetry and geometric accuracy and to reduce all associated risk factors. This study investigates the validity of Leksell Gamma plan (LGP)10.1.1 system of 5th generation Gamma Knife Perfexion as modified variable ellipsoid modeling technique (VEMT) method. METHODS To verify LGP10.1.1 system, we compare the treatment plan program system of the Gamma Knife Perfexion, that is, the LGP, with the calculated value of the proposed modified VEMT program. To verify a modified VEMT method, we compare the distributions of the dose of Gamma Knife Perfexion measured by Gafchromic EBT3 and EBT-XD films. For verification, the center of an 80 mm radius solid water phantom is placed in the center of all sectors positioned at 16 mm, 4 mm and 8 mm; that is, the dose distribution is similar to the method used in the x, y, and z directions by the VEMT. The dose distribution in the axial direction is compared and analyzed based on Full-Width-of-Half-Maximum (FWHM) evaluation. RESULTS The dose profile distribution was evaluated by FWHM, and it showed an average difference of 0.104 mm for the LGP value and 0.130 mm for the EBT-XD film. CONCLUSION The modified VEMT yielded consistent results in the two processes. The use of the modified VEMT as a verification tool can enable the system to stably test and operate the Gamma Knife Perfexion treatment planning system.
Collapse
Affiliation(s)
- Beong Ik Hur
- Department of Neurosurgery, Pusan National University Hospital, Busan, Korea
| | - Seong Jin Jin
- Gamma-knife Center, Haeundae Paik Hospital, Inje University, Busan, Korea
| | - Gyeong Rip Kim
- Gamma-knife Center, Pusan National University Yangsan Hospital, Yangsan, Korea.,Department of Neurosurgery, Pusan National University Yangsan Hospital, Yangsan, Korea
| | - Jong Hyeok Kwak
- Department of Radiology, Pusan National University Yangsan Hospital, Yangsan, Korea
| | - Young Ha Kim
- Department of Neurosurgery, Pusan National University Yangsan Hospital, Yangsan, Korea
| | - Sang Weon Lee
- Gamma-knife Center, Pusan National University Yangsan Hospital, Yangsan, Korea.,Department of Neurosurgery, Pusan National University Yangsan Hospital, Yangsan, Korea
| | - Soon Ki Sung
- Gamma-knife Center, Pusan National University Yangsan Hospital, Yangsan, Korea.,Department of Neurosurgery, Pusan National University Yangsan Hospital, Yangsan, Korea
| |
Collapse
|
8
|
Curry CB, Dunning CAS, Gauthier M, Chou HGJ, Fiuza F, Glenn GD, Tsui YY, Bazalova-Carter M, Glenzer SH. Optimization of radiochromic film stacks to diagnose high-flux laser-accelerated proton beams. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2020; 91:093303. [PMID: 33003776 DOI: 10.1063/5.0020568] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 08/26/2020] [Indexed: 06/11/2023]
Abstract
Here, we extend flatbed scanner calibrations of GafChromic EBT3, MD-V3, and HD-V2 radiochromic films using high-precision x-ray irradiation and monoenergetic proton bombardment. By computing a visibility parameter based on fractional errors, optimal dose ranges and transitions between film types are identified. The visibility analysis is used to design an ideal radiochromic film stack for the proton energy spectrum expected from the interaction of a petawatt laser with a cryogenic hydrogen jet target.
Collapse
Affiliation(s)
- C B Curry
- High Energy Density Science Division, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - C A S Dunning
- Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia V8P 5C2, Canada
| | - M Gauthier
- High Energy Density Science Division, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - H-G J Chou
- High Energy Density Science Division, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - F Fiuza
- High Energy Density Science Division, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - G D Glenn
- High Energy Density Science Division, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Y Y Tsui
- Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| | - M Bazalova-Carter
- Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia V8P 5C2, Canada
| | - S H Glenzer
- High Energy Density Science Division, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| |
Collapse
|
9
|
Parsons D, Zhang Y, Gu X, Lu W. POD‐DOSI: A dedicated dosimetry system for GammaPod commissioning and quality assurance. Med Phys 2020; 47:3647-3657. [DOI: 10.1002/mp.14221] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 04/22/2020] [Accepted: 04/23/2020] [Indexed: 11/05/2022] Open
Affiliation(s)
- David Parsons
- Department of Radiation Oncology University of Texas Southwestern Medical Center 2280 Inwood Rd. Dallas TX 75390 USA
| | - You Zhang
- Department of Radiation Oncology University of Texas Southwestern Medical Center 2280 Inwood Rd. Dallas TX 75390 USA
| | - Xuejun Gu
- Department of Radiation Oncology University of Texas Southwestern Medical Center 2280 Inwood Rd. Dallas TX 75390 USA
| | - Weiguo Lu
- Department of Radiation Oncology University of Texas Southwestern Medical Center 2280 Inwood Rd. Dallas TX 75390 USA
| |
Collapse
|
10
|
Assessment of Angular Spectral Distributions of Laser Accelerated Particles for Simulation of Radiation Dose Map in Target Normal Sheath Acceleration Regime of High Power Laser-Thin Solid Target Interaction—Comparison with Experiments. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10124390] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
An adequate simulation model has been used for the calculation of angular and energy distributions of electrons, protons, and photons emitted during a high-power laser, 5-µm thick Ag target interaction. Their energy spectra and fluencies have been calculated between 0 and 360 degrees around the interaction point with a step angle of five degrees. Thus, the contribution of each ionizing species to the total fluency value has been established. Considering the geometry of the experimental set-up, a map of the radiation dose inside the target vacuum chamber has been simulated, using the Geant4 General Particle Source code, and further compared with the experimental one. Maximum values of the measured dose of the order of tens of mGy per laser shot have been obtained in the direction normal to the target at about 30 cm from the interaction point.
Collapse
|
11
|
Becker S, Sabouri P, Niu Y, Prado K, Chen S, Nichols E, Yi B. Commissioning and acceptance guide for the GammaPod. ACTA ACUST UNITED AC 2019; 64:205021. [DOI: 10.1088/1361-6560/ab41bd] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
12
|
Soliman K, Adili M, Alrushoud A. Radiation dose verification of an X-ray based blood irradiator using EBT3 radiochromic films calibrated using Gamma Knife machine. Rep Pract Oncol Radiother 2019; 24:369-374. [PMID: 31198412 DOI: 10.1016/j.rpor.2019.05.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 03/06/2019] [Accepted: 05/11/2019] [Indexed: 11/20/2022] Open
Abstract
Aim Blood irradiators (BI) initial acceptance testing and routine annual dosimetry checks require radiation dose measurements in order to comply with regulatory requirements. Background Traditionally thermo-luminescence dosimeters (TLD) have been used to measure the dose. The EBT3 film is reported to be a better dosimeter for low energy X-rays than its predecessors EBT2 and EBT. To the best of our knowledge, the use of EBT3 films to perform dosimetry on X-ray based BI has not been reported yet. Materials and methods We performed routine radiation dosimetry checks using EBT3 films on a new X-ray based BI and compared the results with TLD dosimetry. Calibration films were irradiated with radiation beam from a Co-60 Gamma Knife (GK) radiosurgery machine and, alternatively, using an Ir-192 high dose rate (HDR) brachytherapy device. The films were calibrated to cover a wide dose range from 1 to 40 Gy. Such a wide dose range has not been reported yet in BI film dosimetry. Results We obtained a relative difference of about 6.6% between doses measured using TLD and those measured using EBT3 films. Both irradiation methods using GK or HDR were found to be adequate for the calibration of the EBT3 Gafchromic films. Conclusions We recommend the use of EBT3 films in routine X-ray based BI dosimetry checks. The presented method takes advantage of available radiotherapy equipment that can be efficiently used for EBT3 films calibration. The method is fast, reproducible and saves valuable medical physicist's time.
Collapse
Affiliation(s)
- Khaled Soliman
- Medical Physics Department, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| | - Marouf Adili
- Medical Physics Department, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| | - Abdullah Alrushoud
- Medical Physics Department, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| |
Collapse
|
13
|
Tagiling N, Ab Rashid R, Azhan SNA, Dollah N, Geso M, Rahman WN. Effect of scanning parameters on dose-response of radiochromic films irradiated with photon and electron beams. Heliyon 2018; 4:e00864. [PMID: 30364574 PMCID: PMC6197593 DOI: 10.1016/j.heliyon.2018.e00864] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 08/11/2018] [Accepted: 10/11/2018] [Indexed: 12/04/2022] Open
Abstract
Proper dosimetry settings are crucial in radiotherapy to ensure accurate radiation dose delivery. This work evaluated scanning parameters as affecting factors in reading the dose-response of EBT2 and EBT3 radiochromic films (RCFs) irradiated with clinical photon and electron beams. The RCFs were digitised using Epson® Expression® 10000XL flatbed scanner and image analyses of net optical density (netOD) were conducted using five scanning parameters i.e. film type, resolution, image bit depth, colour to grayscale transformation and image inversion. The results showed that increasing spatial resolution and deepening colour depth did not improve film sensitivity, while grayscale scanning caused sensitivity reduction below than that detected in the Red-channel. It is also evident that invert and colour negative film type selection negated netOD values, hence unsuitable for scanning RCFs. In conclusion, choosing appropriate scanning parameters are important to maintain preciseness and reproducibility in films dosimetry.
Collapse
Affiliation(s)
- Nashrulhaq Tagiling
- Medical Radiation Programme, School of Health Sciences, Universiti Sains Malaysia (Health Campus), Kelantan, Malaysia
| | - Raizulnasuha Ab Rashid
- Medical Radiation Programme, School of Health Sciences, Universiti Sains Malaysia (Health Campus), Kelantan, Malaysia
| | - Siti Nur Amirah Azhan
- Medical Radiation Programme, School of Health Sciences, Universiti Sains Malaysia (Health Campus), Kelantan, Malaysia
| | - Norhayati Dollah
- Department of Nuclear Medicine, Radiotherapy and Oncology, Hospital Universiti Sains Malaysia (HUSM), Kelantan, Malaysia
| | - Moshi Geso
- Division of Medical Radiation, School of Health and Biomedical Sciences, RMIT University, Bundoora, Victoria, Australia
| | - Wan Nordiana Rahman
- Medical Radiation Programme, School of Health Sciences, Universiti Sains Malaysia (Health Campus), Kelantan, Malaysia
| |
Collapse
|
14
|
Penumbra width determination of single beam and 201 beams of Gamma Knife machine model 4C using Monte Carlo simulation. JOURNAL OF RADIOTHERAPY IN PRACTICE 2018. [DOI: 10.1017/s1460396918000407] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
AbstractBackgroundOne of the stereotactic radiosurgery techniques is Gamma Knife radiosurgery, in which intracranial lesions that are inaccessible or inappropriate for surgery are treated using 201 cobalt-60 sources in one treatment session. In this conformal technique, the penumbra width, which results in out-of-field dose in tumour-adjacent normal tissues should be determined accurately. The aim of this study is to calculate the penumbra widths of single and 201 beams for different collimator sizes of Gamma Knife machine model 4C using EGSnrc/BEAMnrc Monte Carlo simulation code and comparison the results with EBT3 film dosimetry data.Methods and materialsIn this study, simulation of Gamma Knife machine model 4C was performed based on the Monte Carlo codes of EGSnrc/BEAMnrc. To investigate the physical penumbra width (80−20%), the single beam and 201 beams profiles were obtained using EGSnrc/DOSXYZnrc code and EBT3 films located at isocentre point in a spherical Plexiglas head phantom.ResultsBased on the results, the single beam penumbra widths obtained from simulation data for 4, 8, 14 and 18 mm collimator sizes alongXaxis were 0·75, 0·77, 0·90 and 0·92 mm, respectively. The data for 201 beams obtained from simulation were 2·61, 4·80, 7·92 and 9·81 mm alongXaxis and 1·31, 1·60, 1·91 and 2·14 mm alongZaxis and from film dosimetry were 3·21, 4·90, 8·00 and 10·61 mm alongXaxis and 1·22, 1·69, 2·01 and 2·25 mm alongZaxis, respectively.ConclusionThe differences between measured and simulated penumbra widths are in an acceptable range. However, for more precise measurement in the penumbra region in which dose gradient is high, Monte Carlo simulation is recommended.
Collapse
|
15
|
Soliman YS, Abdel-Fattah AA, Alkhuraiji TS. Radiochromic film containing poly(hexa-2,4-diynylene adipate) as a radiation dosimeter. Appl Radiat Isot 2018; 141:80-87. [PMID: 30195104 DOI: 10.1016/j.apradiso.2018.08.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 08/19/2018] [Accepted: 08/19/2018] [Indexed: 11/30/2022]
Abstract
A radiation-sensitive polymer poly(hexa-2,4-diynylene adipate) (PHDA) was synthesized and incorporated into polyvinyl butyral films for radiation dose measurements in the 0.5 - 60 kGy range. PHDA undergoes crosslinking polymerization upon exposure to γ-rays, which changes its color from very pale yellow to deep orange-yellow. The color change is directly related to the absorbed dose. The absorption spectrum of the irradiated films features one absorption band around 500 nm with a shoulder around 465 nm. With increasing absorbed dose, the two bands grow in intensity and move towards higher wavelengths. The dosimeter is nearly insensitive to variations of the humidity in the range of 0-54% and temperature in the range of 30-45 °C during irradiation. The color intensifies after irradiation, both in the dark and in the light at room temperature, which reflects the continuing crosslinking polymerization. However, at - 4 °C, the color intensity does not change with time.
Collapse
Affiliation(s)
- Yasser S Soliman
- National Center for Radiation Research and Technology, Atomic Energy Authority, P.O. box 8029 Nasr City, Cairo, Egypt.
| | - Atef A Abdel-Fattah
- National Center for Radiation Research and Technology, Atomic Energy Authority, P.O. box 8029 Nasr City, Cairo, Egypt
| | - Turki S Alkhuraiji
- King Abdulaziz City for Science and Technology, National Center for Irradiation Technology, Riyadh, Saudi Arabia
| |
Collapse
|
16
|
Najafi M, Shirazi A, Geraily G, Esfahani M, Teimouri J. Evaluation of dose profiles using Gafchromic EBT3 films in Leksell Gamma Knife 4C around inhomogeneities in the treatment of pituitary adenoma in anthropomorphic heterogeneous head phantom. Radiat Phys Chem Oxf Engl 1993 2018. [DOI: 10.1016/j.radphyschem.2018.04.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
|