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Scott H, Alvarez PE, Howell RM, Riegel A, Sun R, Liu K, Kry SF. Chromatic bleaching and fractionation effects on optically stimulated luminescent dosimeter reuse. Med Phys 2024. [PMID: 38852196 DOI: 10.1002/mp.17231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 04/14/2024] [Accepted: 05/02/2024] [Indexed: 06/11/2024] Open
Abstract
BACKGROUND Optically stimulated luminescent dosimeters (OSLDs) can be bleached and reused, but questions remain about the effects of repeated bleaching and fractionation schedules on OSLD performance. PURPOSE The aim of this study was to investigate how light sources with different wavelengths and different fractionation schemes affect the performance of reused OSLDs. METHODS OSLDs (N = 240) were irradiated on a cobalt-60 beam in different step sizes until they reached an accumulated dose of 50 Gy. Between irradiations they were bleached using light sources of different wavelengths: the Imaging and Radiation Oncology Core (IROC) bleaching system (our control); monochromatic red, green, yellow, and blue lights; and a polychromatic white light. Sensitivity and linearity-based correction factors were determined as a function of dose step-size. The rate of signal removal from different light sources was characterized by sampling these OSLDs at various time points during their bleaching process. Relative doses were calculated according to the American Association of Physicists in Medicine Task Group-191. Signal repopulation was investigated by irradiating OSLDs (N = 300) to various delivered doses of 2, 10, 20, 30, 40, and 50 Gy in a single fraction, bleached with one of the colors, and read over time. Fractionation effects were evaluated by irradiating OSLDs up to 30 Gy in different size steps. After reading, the OSLDs were bleached following IROC protocol. OSLDs (N = 40) received irradiations in 5, 10, 15, 30 Gy fractions until they had an accumulated dose of 30 Gy; The sensitivity response of these OSLDs was compared with reference OSLDs that had no accumulated dose. RESULTS Light sources with polychromatic spectrums (IROC and white) bleached OSLDs faster than did sources with monochromatic spectra. Polychromatic light sources (white light and IROC system) provided the greatest dose stability for OSLDs that had larger amounts of accumulated dose. Signal repopulation was related to the choice of bleaching light source, timing of bleaching, and amount of accumulated dose. Changes to relative dosimetry were more pronounced in OSLDs that received larger fractions. At 5-Gy fractions and above, all OSLDs had heightened sensitivity, with OSLDs exposed to 30-Gy fractions being 6.4% more sensitive than reference dosimeters. CONCLUSIONS The choice of bleaching light plays a role in how fast an OSLD is bleached and how much accumulated dose an OSLD can be exposed to while maintaining stable signal sensitivity. We have expanded upon investigations into signal repopulation to show that bleaching light plays a role in the migration of deep traps to dosimetric traps after bleaching. Our research concludes that the bleaching light source and fractionation need to be considered when reusing OSLD.
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Affiliation(s)
- Hayden Scott
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
- The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, Texas, USA
| | - Paola E Alvarez
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Rebecca M Howell
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
- The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, Texas, USA
| | - Adam Riegel
- Department of Radiation Oncology, Columbia University Irving Medical Center, New York City, New York, USA
| | - Ryan Sun
- The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, Texas, USA
- Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Kevin Liu
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
- The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, Texas, USA
| | - Stephen F Kry
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
- The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, Texas, USA
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K E R, Krishnan M. Surface dose measurement and comparison between TLD and OSLD during modified re constructive mastectomy irradiation. Biomed Phys Eng Express 2024; 10:045025. [PMID: 38714180 DOI: 10.1088/2057-1976/ad47fd] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Accepted: 05/07/2024] [Indexed: 05/09/2024]
Abstract
Radiotherapy (RT) is one of the major treatment modalities among surgery and chemotherapy for carcinoma breast. The surface dose study of modified reconstructive constructive Mastectomy (MRM) breast is important due to the heterogeneity in the body contour and the conventional treatment angle to save the lungs and heart from the radiation. These angular entries of radiation beam cause an unpredictable dose deposition on the body surface, which has to be monitored. Thermoluminescent dosimeter (TLD) or optically stimulated luminescent dosimeter (nano OSLD) are commonly preferable dosimeters for this purpose. The surface dose response of TLD and nano OSLD during MRM irradiation has been compared with the predicted dose from the treatment planning system (TPS). The study monitored 100 MRM patients by employing a total 500 dosimeters consisting of TLD (n = 250) and nano OSLD (n = 250), during irradiation from an Elekta Versa HD 6 MV Linear accelerator. The study observed a variance of 3.9% in the dose measurements for TLD and 3.2% for nano OSLD from the planned surface dose, with a median percentage dose of 44.02 for nano OSLD and 40.30 for TLD (p value 0.01). There was no discernible evidence of variation in dose measurements attributable to differences in field size or from patient to patient. Additionally, no variation was observed in dose measurements when comparing the placement of the dosimeter from central to off-centre positions. In comparison, a minor difference in dose measurements were noted between TLD and nano OSLD, The study's outcomes support the applicability of both TLD and nano OSLD as effective dosimeters during MRM breast irradiation for surface dose evaluation.
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Affiliation(s)
- Ratheesh K E
- Department of Medical Physics, Centre for Interdisciplinary Research, D. Y. Patil Education Society (Deemed to be University), Kolhapur, Maharashtra, India
| | - Mayakannan Krishnan
- Department of Medical Physics, Centre for Interdisciplinary Research, D. Y. Patil Education Society (Deemed to be University), Kolhapur, Maharashtra, India
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Webster M, Dona Lemus OM, Zheng D, Wancura JN, Tanny S, Sakthivel G, Constine L. Case study with dosimetric analysis: Total body irradiation to a patient with a left ventricular assist device. Clin Case Rep 2024; 12:e8868. [PMID: 38756618 PMCID: PMC11096280 DOI: 10.1002/ccr3.8868] [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: 02/14/2024] [Revised: 04/03/2024] [Accepted: 04/11/2024] [Indexed: 05/18/2024] Open
Abstract
Key Clinical Message A patient presented with cardiogenic shock, requiring the implantation of a left ventricular assist device (LVAD), and acute myeloblastic leukemia. This necessitated total body irradiation (TBI) while balancing dose reduction to the LVAD components to avoid potential radiation damage. Here we outline our treatment approach and dose estimates to the LVAD. Abstract This case report discusses the delivery of TBI to a patient with an LVAD. This treatment required radiation-dose determinations and consequential reductions for the heart, LVAD, and an external controller connected to the LVAD. The patient was treated using a traditional 16MV anterior posterior (AP)/posterior anterior (PA) technique at a source-to-surface-distance of 515 cm for 400 cGy in two fractions. A 3 cm thick Cerrobend block was placed on the beam spoiler to reduce dose to the heart and LVAD to 150 cGy. The external controller was placed in a 1 cm thick acrylic box to reduce neutron dose and positioned as far from the treatment fields as achievable. In vivo measurements were made using optically stimulated luminescence dosimeters (OSLDs) placed inside the box at distances of 2 cm, 8.5 cm, and 14 cm from the field edge, and on the patient along the central axis and centered behind the LVAD block. Further ion chamber measurements were made using a solid water phantom to more accurately estimate the dose delivered to the LVAD. Neutron dose measurements were also conducted. The total estimated dose to the controller ranged from 135.3 cGy to 91.5 cGy. The LVAD block reduced the surface dose to the patient to 271.6 cGy (68.1%). The block transmission factors of the 3 cm Cerrobend block measured in the phantom were 45% at 1 cm depth and decreased asymptotically to around 30% at 3 cm depth. Applying these transmission factors to the in vivo measurements yielded a dose of 120 cGy to the implanted device. The neutron dose the LVAD region is estimated around 0.46 cGy. Physical limitations of the controller made it impossible to completely avoid dose. Shielding is recommended. The block had limited dose reduction to the surface, due to secondary particles, but appropriately reduced the dose at 3 cm and beyond. More research on LVADs dose limits would be beneficial.
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Affiliation(s)
- Matthew Webster
- Department of Radiation OncologyUniversity of Rochester Medical CenterRochesterNew YorkUSA
| | - Olga M. Dona Lemus
- Department of Radiation OncologyUniversity of Rochester Medical CenterRochesterNew YorkUSA
| | - Dandan Zheng
- Department of Radiation OncologyUniversity of Rochester Medical CenterRochesterNew YorkUSA
| | - Joshua N. Wancura
- Department of Radiation OncologyUniversity of Rochester Medical CenterRochesterNew YorkUSA
| | - Sean Tanny
- Department of Radiation OncologyUniversity of Rochester Medical CenterRochesterNew YorkUSA
| | - Gukan Sakthivel
- Department of Radiation OncologyUniversity of Rochester Medical CenterRochesterNew YorkUSA
| | - Louis Constine
- Department of Radiation OncologyUniversity of Rochester Medical CenterRochesterNew YorkUSA
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Yip E, Tari SY, Reynolds MW, Sinn D, Murray BR, Fallone BG, Oliver PA. Clinical reference dosimetry for the 0.5 T inline rotating biplanar Linac-MR. Med Phys 2024; 51:2933-2940. [PMID: 38308821 DOI: 10.1002/mp.16951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 11/13/2023] [Accepted: 12/26/2023] [Indexed: 02/05/2024] Open
Abstract
BACKGROUND The world's first clinical 0.5 T inline rotating biplanar Linac-MR system is commissioned for clinical use. For reference dosimetry, unique features to device, including an SAD = 120 cm, bore clearance of 60 cm × 110 cm, as well as 0.5 T inline magnetic field, provide some challenges to applying a standard dosimetry protocol (i.e., TG-51). PURPOSE In this work, we propose a simple and practical clinical reference dosimetry protocol for the 0.5T biplanar Linac-MR and validated its results. METHODS Our dosimetry protocol for this system is as follows: tissue phantom ratios at 20 and 10 cm are first measured and converted into %dd10x beam quality specifier using equations provided and Kalach and Rogers. The converted %dd10x is used to determine the ion chamber correction factor, using the equations in the TG-51 addendum for the Exradin A12 farmer chamber used, which is cross-calibrated with one calibrated at a standards laboratory. For a 0.5 T parallel field, magnetic field effect on chamber response is assumed to have no effect and is not explicitly corrected for. Once the ion chamber correction factor for a non-standard SAD (kQ,msr) is determined, TG-51 is performed to obtain dose at a depth of 10 cm at SAD = 120 cm. The dosimetry protocol is repeated with the magnetic field ramped down. To validate our dosimetry protocol, Monte Carlo (EGSnrc) simulations are performed to confirm the determined kQ,msr values. MC Simulations and magnetic Field On versus Field Off measurements are performed to confirm that the magnetic field has no effect. To validate our overall dosimetry protocol, external dose audits, based on optical simulated luminescent dosimeters, thermal luminescent dosimeters, and alanine dosimeters are performed on the 0.5 T Linac-MR system. RESULTS Our EGSnrc results confirm our protocol-determined kQ,msr values, as well as our assumptions about magnetic field effects (kB = 1) within statistical uncertainty for the A-12 chamber. Our external dosimetry procedures also validated our overall dosimetry protocol for the 0.5 T biplanar Linac-MR hybrid. Ramping down the magnetic field has resulted in a dosimetric difference of 0.1%, well within experimental uncertainty. CONCLUSION With the 0.5 T parallel magnetic field having minimal effect on the ion chamber response, a TPR20,10 approach to determine beam quality provides an accurate method to perform clinical dosimetry for the 0.5 T biplanar Linac-MR.
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Affiliation(s)
- Eugene Yip
- Department of Oncology, Medical Physics Division, University of Alberta, Edmonton, Alberta, Canada
- Department of Medical Physics, Cross Cancer Institute, Edmonton, Alberta, Canada
| | - Shima Y Tari
- Department of Oncology, Medical Physics Division, University of Alberta, Edmonton, Alberta, Canada
- Department of Medical Physics, Cross Cancer Institute, Edmonton, Alberta, Canada
| | - Michael W Reynolds
- Department of Medical Physics, Cross Cancer Institute, Edmonton, Alberta, Canada
- Department of Radiation Oncology, BC Cancer - Victoria, Victoria, British Columbia, Canada
| | - David Sinn
- Department of Medical Physics, Cross Cancer Institute, Edmonton, Alberta, Canada
- Department of Radiaiton Oncology, The Queen's Medical Centre, Honolulu, Hawaii, USA
| | - Brad R Murray
- MagnetTx Oncology Solutions, Edmonton, Alberta, Canada
| | - B Gino Fallone
- Department of Oncology, Medical Physics Division, University of Alberta, Edmonton, Alberta, Canada
- Department of Medical Physics, Cross Cancer Institute, Edmonton, Alberta, Canada
- MagnetTx Oncology Solutions, Edmonton, Alberta, Canada
| | - Patricia Ak Oliver
- Department of Oncology, Medical Physics Division, University of Alberta, Edmonton, Alberta, Canada
- Department of Medical Physics, Cross Cancer Institute, Edmonton, Alberta, Canada
- Department of Medical Physics, Nova Scotia Health, Halifax, Nova Scotia, Canada
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Dries W, Petoukhova A, Hertsens N, Stevens P, Jarbinet V, Bimmel-Nagel CH, Weterings J, van Wingerden K, Bauwens C, Vanreusel V, Simon S. Intraoperative electron beam intercomparison of 6 sites using mailed thermoluminescence dosimetry: Absolute dose and energy. Phys Med 2024; 119:103302. [PMID: 38310679 DOI: 10.1016/j.ejmp.2024.103302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 01/19/2024] [Accepted: 01/26/2024] [Indexed: 02/06/2024] Open
Abstract
PURPOSE In 2018, the Netherlands Commission on Radiation Dosimetry subcommittee on IORT initiated a limited intercomparison of electron IORT (IOERT) in Belgium and The Netherlands. The participating institutions have enough variability in age, type of equipment, and in dose calibration protocols. METHODS In this study, three types of IOERT-dedicated mobile accelerators were represented: Mobetron 2000, LIAC HWL and LIAC. Mobetron produces electron beams with energies of 6, 9 and 12 MeV, while LIAC HWL and LIAC can deliver 6, 8, 10 and 12 MeV electron beams. For all energies, the reference beam (10 cm diameter, 0° incidence) and 5 cm diameter beams were measured, as these smaller beams are used more frequently in clinic. The mailed TLD service from the Radiation Dosimetry Services (RDS, Houston, USA) has been used. Following RDS' standard procedures, each beam was irradiated to 300 cGy at dmax with TLDs around dmax and around depth of 50 % dose (R50). Absolute dose at 100 % and beam energy, expressed as R50, could be verified in this way. RESULTS All absolute doses and energies under reference conditions were well within RDS-stated uncertainties: dose deviations were <5 % and deviations in R50 were <5 mm. For the small 5 cm beams, all results were also within acceptance levels except one absolute dose value. Deviations were not significantly dependent on manufacturer, energy, diameter and calibration protocol. CONCLUSIONS All absolute dose values, except one of a non-reference beam, and all energy values were well within the measurement accuracy of RDS TLDs.
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Affiliation(s)
- Wim Dries
- Catharina Hospital, Eindhoven, The Netherlands
| | - Anna Petoukhova
- Haaglanden Medical Centre, Department of Medical Physics, Leidschendam, The Netherlands.
| | | | | | | | | | | | - Ko van Wingerden
- Haaglanden Medical Centre, Department of Medical Physics, Leidschendam, The Netherlands
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Liu K, Velasquez B, Schüler E. Technical note: High-dose and ultra-high dose rate (UHDR) evaluation of Al 2 O 3 :C optically stimulated luminescent dosimeter nanoDots and powdered LiF:Mg,Ti thermoluminescent dosimeters for radiation therapy applications. Med Phys 2024; 51:2311-2319. [PMID: 37991111 PMCID: PMC10939935 DOI: 10.1002/mp.16832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 09/11/2023] [Accepted: 10/25/2023] [Indexed: 11/23/2023] Open
Abstract
BACKGROUND Dosimetry in ultra-high dose rate (UHDR) electron beamlines poses a significant challenge owing to the limited usability of standard dosimeters in high dose and high dose-per-pulse (DPP) applications. PURPOSE In this study, Al2 O3 :C nanoDot optically stimulated luminescent dosimeters (OSLDs), single-use powder-based LiF:Mg,Ti thermoluminescent dosimeters (TLDs), and Gafchromic EBT3 film were evaluated at extended dose ranges (up to 40 Gy) in conventional dose rate (CONV) and UHDR beamlines to determine their usability for calibration and dose verification in the setting of FLASH radiation therapy. METHODS OSLDs and TLDs were evaluated against established dose-rate-independent Gafchromic EBT3 film with regard to the potential influence of mean dose rate, instantaneous dose rate, and DPP on signal response. The dosimeters were irradiated at CONV or UHDR conditions on a 9-MeV electron beam. Under UHDR conditions, different settings of pulse repetition frequency (PRF), pulse width (PW), and pulse amplitude were used to characterize the individual dosimeters' response in order to isolate their potential dependencies on dose, dose rate, and DPP. RESULTS The OSLDs, TLDs, and Gafchromic EBT3 film were found to be suitable at a dose range of up to 40 Gy without any indication of saturation in signal. The response of OSLDs and TLDs in UHDR conditions were found to be independent of mean dose rate (up to 1440 Gy/s), instantaneous dose rate (up to 2 MGy/s), and DPP (up to 7 Gy), with uncertainties on par with nominal values established in CONV beamlines (± 4%). In cross-comparing the response of OSLDs, TLDs and Gafchromic film at dose rates of 0.18-245 Gy/s, the coefficient of variation or relative standard deviation in the measured dose between the three dosimeters (inter-dosimeter comparison) was found to be within 2%. CONCLUSIONS We demonstrated the dynamic range of OSLDs, TLDs, and Gafchromic film to be suitable up to 40 Gy, and we developed a protocol that can be used to accurately translate the measured signal in each respective dosimeter to dose. OSLDs and powdered TLDs were shown to be viable for dosimetric measurement in UHDR beamlines, providing dose measurements with accuracies on par with Gafchromic EBT3 film and their concurrent use demonstrating a means for redundant dosimetry in UHDR conditions.
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Affiliation(s)
- Kevin Liu
- Division of Radiation Oncology, Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
- The University of Texas MD Anderson Cancer Center UTHealth Houston Graduate School of Biomedical Sciences, Houston, Texas, USA
| | - Brett Velasquez
- Division of Radiation Oncology, Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Emil Schüler
- Division of Radiation Oncology, Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
- The University of Texas MD Anderson Cancer Center UTHealth Houston Graduate School of Biomedical Sciences, Houston, Texas, USA
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Kakade NR, Kumar R, Sharma SD, Sapra BK. Dosimetry audit in advanced radiotherapy using in-house developed anthropomorphic head & neck phantom. Biomed Phys Eng Express 2024; 10:025022. [PMID: 38269653 DOI: 10.1088/2057-1976/ad222a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 01/24/2024] [Indexed: 01/26/2024]
Abstract
The treatment of head and neck (H&N) cancer presents formidable challenges due to the involvement of normal tissue and organs at risk (OARs) in the close vicinity. Ensuring the precise administration of the prescribed dose demands prior dose verification. Considering contour irregularity and heterogeneity in the H&N region, an anthropomorphic and heterogeneous H&N phantom was developed and fabricated locally for conducting the dosimetry audit in advanced radiotherapy treatments. This specialized phantom emulates human anatomy and incorporates a removable cylindrical insert housing a C-shaped planning target volume (PTV) alongside key OARs including the spinal cord, oral cavity, and bilateral parotid glands. Acrylonitrile Butadiene Styrene (ABS) was chosen for PTV and parotid fabrication, while Delrin was adopted for spinal cord fabrication. A pivotal feature of this phantom is the incorporation of thermoluminescent dosimeters (TLDs) within the PTV and OARs, enabling the measurement of delivered dose. To execute the dosimetry audit, the phantom, accompanied by dosimeters and comprehensive guidelines, was disseminated to multiple radiotherapy centers. Subsequently, hospital physicists acquired computed tomography (CT) scans to generate treatment plans for phantom irradiation. The treatment planning system (TPS) computed the anticipated dose distribution within the phantom, and post-irradiation TLD readings yielded actual dose measurements. The TPS calculated and TLD measured dose values at most of the locations inside the PTV were found comparable within ± 4%. The outcomes affirm the suitability of the developed anthropomorphic H&N phantom for precise dosimetry audits of advanced radiotherapy treatments.
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Affiliation(s)
- Nitin R Kakade
- Radiological Physics & Advisory Division, Bhabha Atomic Research Centre, Mumbai-400094, India
| | - Rajesh Kumar
- Radiological Physics & Advisory Division, Bhabha Atomic Research Centre, Mumbai-400094, India
| | - S D Sharma
- Radiological Physics & Advisory Division, Bhabha Atomic Research Centre, Mumbai-400094, India
- Homi Bhabha National Institute, Mumbai-400094, India
| | - B K Sapra
- Radiological Physics & Advisory Division, Bhabha Atomic Research Centre, Mumbai-400094, India
- Homi Bhabha National Institute, Mumbai-400094, India
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Ratheesh KE, Mayakannan K. Angular dependence of the TL and OSL dosimeters in the clinical 6 MV photon Beam. Appl Radiat Isot 2023; 202:111073. [PMID: 37890243 DOI: 10.1016/j.apradiso.2023.111073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Revised: 10/05/2023] [Accepted: 10/16/2023] [Indexed: 10/29/2023]
Abstract
The angular response of luminescent dosimeters (LD), in particular TLD and OSLD, has been compared by applying 6 MV X-ray photons from Versa HD clinical linear accelerator. The study admitted for the irradiation of TLD (n = 475) and OSLD (n = 475) under phantom set up in various gantry angles from 00 to ±900 and various field sizes from 10 x 10 cm2 to 30 x 30 cm2. The variance in the output was observed between 4.4% for TLD and 3.9% for OSLD. A significant deviation from the desired output was detected, towards the angle of incidents, at ±800 to ±900. Additionally, there is no evidence of variation in the dose measurement due to the difference in field size. These results demonstrate a good approximation to the vendor-specified tolerance limits, justifying the use of these LDs within angular incidents of radiation up to ±700. The TLD and OSLD better dose-response is achieved to a gantry angle up to ±700 from the perpendicular incidents. The result shows that both TLD and OSLD could be used as dosimeters for a treatment field that does not extend beyond ±700 beam angle.
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Affiliation(s)
- K E Ratheesh
- D. Y. Patil Education Society (Deemed to be University), Kolhapur, Maharashtra, India
| | - Krishnan Mayakannan
- D. Y. Patil Education Society (Deemed to be University), Kolhapur, Maharashtra, India.
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Lin LL, Ndlovu N, Lowenstein J, Wirth M, Lee J, Stier EA, Garg M, Kotzen J, Kadzatsa W, Palefsky J, Krown SE, Einstein MH. Quality Assurance in Clinical Trials Requiring Radiation Therapy in Sub-Saharan Africa. Int J Radiat Oncol Biol Phys 2023; 116:439-447. [PMID: 36493958 PMCID: PMC10360026 DOI: 10.1016/j.ijrobp.2022.11.042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Revised: 11/09/2022] [Accepted: 11/28/2022] [Indexed: 12/12/2022]
Abstract
PURPOSE Given the increasing availability of radiation therapy in sub-Saharan Africa, clinical trials that include radiation therapy are likely to grow. Ensuring appropriate delivery of radiation therapy through rigorous quality assurance is an important component of clinical trial execution. We reviewed the process for credentialing radiation therapy sites and radiation therapy quality assurance through the Imaging and Radiation Oncology Core (IROC) Houston Quality Assurance Center for AIDS Malignancy Consortium (AMC)-081, a multicenter study of cisplatin and radiation therapy for women with locally advanced cervical cancer living with HIV, conducted by the AIDS Malignancy Consortium at 2 sites in South Africa and Zimbabwe. METHODS AND MATERIALS Women living with HIV with newly diagnosed stage IB2, IIA (>4 cm), IIB-IVA cervical carcinoma (per the 2009 International Federation of Gynecology and Obstetrics [FIGO] staging classifications) were enrolled in AMC-081. They received 3-dimensional conformal external beam radiation therapy (EBRT) to the pelvis (41.4-45 Gy) using a linear accelerator, high-dose-rate brachytherapy (6-9 Gy to point A with each fraction and up to 4 fractions), and concurrent weekly cisplatin (40 mg/m2). IROC reviewed EBRT and brachytherapy quality assurance records after treatment. RESULTS All of the 38 women enrolled in AMC-081 received ±5% of the protocol-specified prescribed dose of EBRT. Geometry of brachytherapy applicator placement was scored as per protocol in all implants. Doses to points A and B, International Commission on Radiation Units and Measurements (ICRU) bladder, or ICRU rectum required correction by IROC in >50% of the implants. In the final evaluation, 58% of participants (n = 22) were treated per protocol, 40% (n = 15) had minor protocol deviations, and 3% (n = 1) had major protocol deviations. No records were received within 60 days of treatment completion as requested in the protocol. CONCLUSIONS Major radiation therapy deviations were low, but timely submission of radiation therapy data did not occur. Future studies, especially those that include specialized radiation therapy techniques such as stereotactic or intensity-modulated radiation therapy, will require pathways to ensure timely and adequate quality assurance.
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Affiliation(s)
- Lilie L Lin
- Department of Radiation Oncology, University of Texas, MD Anderson Cancer Center, Houston, Texas.
| | - Ntokozo Ndlovu
- College of Health Sciences, University of Zimbabwe, Harare, Zimbabwe
| | - Jessica Lowenstein
- Department of Radiation Physics and the Imaging and Radiation Oncology Core, University of Texas, MD Anderson Cancer Center, Houston, Texas
| | | | - Jeannette Lee
- Department of Biostatistics, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Elizabeth A Stier
- Department of Obstetrics and Gynecology, Boston University School of Medicine, Boston, Massachusetts
| | - Madhur Garg
- Department of Radiation Oncology, Montefiore Medical Center, Albert Einstein College of Medicine, Yeshiva University, New York, New York
| | - Jeffrey Kotzen
- Department of Radiation Oncology, University of the Witwatersrand, Johannesburg, South Africa
| | - Webster Kadzatsa
- Department of Radiotherapy and Oncology, College of Health Science, University of Zimbabwe, Harare, Zimbabwe
| | - Joel Palefsky
- Department of Medicine, University of California, San Francisco, California
| | - Susan E Krown
- Memorial Sloan Kettering Cancer Center, New York, New York
| | - Mark H Einstein
- Department of Obstetrics, Gynecology, and Women's Health, Rutgers New Jersey Medical School, Newark, New Jersey
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Hosseini Bojdani SM, Baghani HR, Robatjazi M, Andreoli S, Azadegan B. Comparison of derived correction factors for effects of ion recombination and photon beam quality index following TG-51 and TRS-398 dosimetry protocols. Appl Radiat Isot 2023; 197:110796. [PMID: 37037135 DOI: 10.1016/j.apradiso.2023.110796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 03/07/2023] [Accepted: 03/28/2023] [Indexed: 04/12/2023]
Abstract
In this study, ion recombination correction factor (kS) and beam quality conversion factor ( [Formula: see text] ) values were extracted following the recommendations of the TRS-398 and TG-51 dosimetry protocols for widely used cylindrical ionization chambers for high energy photon beam dosimetry to quantify the agreement between the instructions for these two protocols for absolute dosimetry inside water. Four different types of cylindrical ionization chambers comprising Farmer (TM30013), Semiflex 0.125 cm3 (TM31010), Semiflex 0.3 cm3 (TM31013), and PinPoint (TM31016) were considered, and kS and [Formula: see text] values were determined at photon energies of 6 MV and 15 MV. The maximum difference between the measured kS values according to the instructions in the TRS-398 and TG-51 protocols was 0.03%. The kS data measured with both protocols agreed well with those measured by using the Jaffe-plot approach, where the maximum difference was about 0.33%. The observed differences between the [Formula: see text] factors measured by using the TRS-398 and TG-51 dosimetry protocols at photon energies of 6 MV and 15 MV were 0.37% and 0.55%, respectively. The [Formula: see text] values measured using the TG-51 dosimetry protocols were slightly closer to those measured by a reference ionization chamber dosimeter. We conclude that the maximum differences were about 0.4% and 0.6% in the absorbed dose measurements according to the TRS-398 and TG-51 instructions at photon energies of 6 MV and 15 MV, respectively. The type of ionization chamber employed also affected the differences, where the maximum and minimum dose differences were found using the Farmer and PinPoint chambers, respectively.
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Affiliation(s)
| | | | - Mostafa Robatjazi
- Medical Physics and Radiological Sciences Department, Sabzevar University of Medical Sciences, Sabzevar, Iran
| | | | - Behnam Azadegan
- Physics Department, Hakim Sabzevari University, Sabzevar, Iran
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11
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Manna F, Pugliese M, Buonanno F, Gherardi F, Iannacone E, La Verde G, Muto P, Arrichiello C. Use of Thermoluminescence Dosimetry for QA in High-Dose-Rate Skin Surface Brachytherapy with Custom-Flap Applicator. SENSORS (BASEL, SWITZERLAND) 2023; 23:3592. [PMID: 37050652 PMCID: PMC10098582 DOI: 10.3390/s23073592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 03/23/2023] [Accepted: 03/24/2023] [Indexed: 06/19/2023]
Abstract
Surface brachytherapy (BT) lacks standard quality assurance (QA) protocols. Commercially available treatment planning systems (TPSs) are based on a dose calculation formalism that assumes the patient is made of water, resulting in potential deviations between planned and delivered doses. Here, a method for treatment plan verification for skin surface BT is reported. Chips of thermoluminescent dosimeters (TLDs) were used for dose point measurements. High-dose-rate treatments were simulated and delivered through a custom-flap applicator provided with four fixed catheters to guide the Iridium-192 (Ir-192) source by way of a remote afterloading system. A flat water-equivalent phantom was used to simulate patient skin. Elekta TPS Oncentra Brachy was used for planning. TLDs were calibrated to Ir-192 through an indirect method of linear interpolation between calibration factors (CFs) measured for 250 kV X-rays, Cesium-137, and Cobalt-60. Subsequently, plans were designed and delivered to test the reproducibility of the irradiation set-up and to make comparisons between planned and delivered dose. The obtained CF for Ir-192 was (4.96 ± 0.25) μC/Gy. Deviations between measured and TPS calculated doses for multi-catheter treatment configuration ranged from -8.4% to 13.3% with an average of 0.6%. TLDs could be included in clinical practice for QA in skin BT with a customized flap applicator.
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Affiliation(s)
- Francesco Manna
- Department of Physics “E. Pancini”, Federico II University, 80126 Naples, Italy
- Centro Servizi Metrologici e Tecnologici Avanzati, Federico II University, 80146 Naples, Italy
| | - Mariagabriella Pugliese
- Department of Physics “E. Pancini”, Federico II University, 80126 Naples, Italy
- National Institute of Nuclear Physics, Section of Naples, 80126 Naples, Italy
| | - Francesca Buonanno
- Radiotherapy Unit, Istituto Nazionale Tumori, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Fondazione G. Pascale, 80131 Naples, Italy
| | - Federica Gherardi
- Radiotherapy Unit, Istituto Nazionale Tumori, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Fondazione G. Pascale, 80131 Naples, Italy
| | - Eva Iannacone
- Radiotherapy Unit, Istituto Nazionale Tumori, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Fondazione G. Pascale, 80131 Naples, Italy
| | - Giuseppe La Verde
- Department of Physics “E. Pancini”, Federico II University, 80126 Naples, Italy
- National Institute of Nuclear Physics, Section of Naples, 80126 Naples, Italy
| | - Paolo Muto
- Radiotherapy Unit, Istituto Nazionale Tumori, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Fondazione G. Pascale, 80131 Naples, Italy
| | - Cecilia Arrichiello
- Radiotherapy Unit, Istituto Nazionale Tumori, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Fondazione G. Pascale, 80131 Naples, Italy
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12
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Jeong S, Kim C, An S, Kwon YC, Pak SI, Cheon W, Shin D, Lim Y, Jeong JH, Kim H, Lee SB. Determination of the proton LET using thin film solar cells coated with scintillating powder. Med Phys 2023; 50:1194-1204. [PMID: 36135795 DOI: 10.1002/mp.15977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 08/30/2022] [Accepted: 08/30/2022] [Indexed: 11/08/2022] Open
Abstract
PURPOSE The amount of luminescent light detected in a scintillator is reduced with increased proton linear energy transfer (LET) despite receiving the same proton dose, through a phenomenon called quenching. This study evaluated the ability of a solar cell coated with scintillating powder (SC-SP) to measure therapeutic proton LET by measuring the quenching effect of the scintillating powder using a solar cell while simultaneously measuring the dose of the proton beam. METHODS SC-SP was composed of a flexible thin film solar cell and scintillating powder. The LET and dose of the pristine Bragg peak in the 14 cm range were calculated using a validated Monte Carlo model of a double scattering proton beam nozzle. The SC-SP was evaluated by measuring the proton beam under the same conditions at specific depths using SC-SP and Markus chamber. Finally, the 10 and 20 cm range pristine Bragg peaks and 5 cm spread-out Bragg peak (SOBP) in the 14 cm range were measured using the SC-SP and the Markus chamber. LETs measured using the SC-SP were compared with those calculated using Monte Carlo simulations. RESULTS The quenching factors of the SC-SP and solar cell alone, which were slopes of linear fit obtained from quenching correction factors according to LET, were 0.027 and 0.070 µm/keV (R2 : 0.974 and 0.975). For pristine Bragg peaks in the 10 and 20 cm ranges, the maximum differences between LETs measured using the SC-SP and calculated using Monte Carlo simulations were 0.5 keV/µm (15.7%) and 1.2 keV/µm (12.0%), respectively. For a 5 cm SOBP proton beam, the LET measured using the SC-SP and calculated using Monte Carlo simulations differed by up to 1.9 keV/µm (18.7%). CONCLUSIONS Comparisons of LETs for pristine Bragg peaks and SOBP between measured using the SC-SP and calculated using Monte Carlo simulations indicated that the solar cell-based system could simultaneously measure both LET and dose in real-time and is cost-effective.
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Affiliation(s)
- Seonghoon Jeong
- Proton Therapy Center, National Cancer Center, Goyang, Korea
| | - Chankyu Kim
- Proton Therapy Center, National Cancer Center, Goyang, Korea
| | - Seohyeon An
- Proton Therapy Center, National Cancer Center, Goyang, Korea.,Department of Physics, Hanyang University, Seoul, Korea
| | - Yong-Cheol Kwon
- Department of Radiation Oncology, Samsung Medical Center, Seoul, Korea
| | - Sang-Il Pak
- Proton Therapy Center, National Cancer Center, Goyang, Korea
| | - Wonjoong Cheon
- Proton Therapy Center, National Cancer Center, Goyang, Korea
| | - Dongho Shin
- Proton Therapy Center, National Cancer Center, Goyang, Korea
| | - Youngkyung Lim
- Proton Therapy Center, National Cancer Center, Goyang, Korea
| | - Jong Hwi Jeong
- Proton Therapy Center, National Cancer Center, Goyang, Korea
| | - Haksoo Kim
- Proton Therapy Center, National Cancer Center, Goyang, Korea
| | - Se Byeong Lee
- Proton Therapy Center, National Cancer Center, Goyang, Korea
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13
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Smith K, Ulin K, Knopp M, Kry S, Xiao Y, Rosen M, Michalski J, Iandoli M, Laurie F, Quigley J, Reifler H, Santiago J, Briggs K, Kirby S, Schmitter K, Prior F, Saltz J, Sharma A, Bishop-Jodoin M, Moni J, Cicchetti MG, FitzGerald TJ. Quality improvements in radiation oncology clinical trials. Front Oncol 2023; 13:1015596. [PMID: 36776318 PMCID: PMC9911211 DOI: 10.3389/fonc.2023.1015596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 01/06/2023] [Indexed: 01/27/2023] Open
Abstract
Clinical trials have become the primary mechanism to validate process improvements in oncology clinical practice. Over the past two decades there have been considerable process improvements in the practice of radiation oncology within the structure of a modern department using advanced technology for patient care. Treatment planning is accomplished with volume definition including fusion of multiple series of diagnostic images into volumetric planning studies to optimize the definition of tumor and define the relationship of tumor to normal tissue. Daily treatment is validated by multiple tools of image guidance. Computer planning has been optimized and supported by the increasing use of artificial intelligence in treatment planning. Informatics technology has improved, and departments have become geographically transparent integrated through informatics bridges creating an economy of scale for the planning and execution of advanced technology radiation therapy. This serves to provide consistency in department habits and improve quality of patient care. Improvements in normal tissue sparing have further improved tolerance of treatment and allowed radiation oncologists to increase both daily and total dose to target. Radiation oncologists need to define a priori dose volume constraints to normal tissue as well as define how image guidance will be applied to each radiation treatment. These process improvements have enhanced the utility of radiation therapy in patient care and have made radiation therapy an attractive option for care in multiple primary disease settings. In this chapter we review how these changes have been applied to clinical practice and incorporated into clinical trials. We will discuss how the changes in clinical practice have improved the quality of clinical trials in radiation therapy. We will also identify what gaps remain and need to be addressed to offer further improvements in radiation oncology clinical trials and patient care.
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Affiliation(s)
- Koren Smith
- Imaging and Radiation Oncology Core-Rhode Island, Department of Radiation Oncology, UMass Chan Medical School, Lincoln, RI, United States
| | - Kenneth Ulin
- Imaging and Radiation Oncology Core-Rhode Island, Department of Radiation Oncology, UMass Chan Medical School, Lincoln, RI, United States
| | - Michael Knopp
- Imaging and Radiation Oncology Core-Ohio, Department of Radiology, The Ohio State University, Columbus, OH, United States
| | - Stephan Kry
- Imaging and Radiation Oncology Core-Houston, Division of Radiation Oncology, University of Texas, MD Anderson, Houston, TX, United States
| | - Ying Xiao
- Imaging and Radiation Oncology Core Philadelphia, Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA, United States
| | - Mark Rosen
- Imaging and Radiation Oncology Core Philadelphia, Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States
| | - Jeff Michalski
- Department of Radiation Oncology, Washington University, St Louis, MO, United States
| | - Matthew Iandoli
- Imaging and Radiation Oncology Core-Rhode Island, Department of Radiation Oncology, UMass Chan Medical School, Lincoln, RI, United States
| | - Fran Laurie
- Imaging and Radiation Oncology Core-Rhode Island, Department of Radiation Oncology, UMass Chan Medical School, Lincoln, RI, United States
| | - Jean Quigley
- Imaging and Radiation Oncology Core-Rhode Island, Department of Radiation Oncology, UMass Chan Medical School, Lincoln, RI, United States
| | - Heather Reifler
- Imaging and Radiation Oncology Core-Rhode Island, Department of Radiation Oncology, UMass Chan Medical School, Lincoln, RI, United States
| | - Juan Santiago
- Imaging and Radiation Oncology Core-Rhode Island, Department of Radiation Oncology, UMass Chan Medical School, Lincoln, RI, United States
| | - Kathleen Briggs
- Imaging and Radiation Oncology Core-Rhode Island, Department of Radiation Oncology, UMass Chan Medical School, Lincoln, RI, United States
| | - Shawn Kirby
- Imaging and Radiation Oncology Core-Rhode Island, Department of Radiation Oncology, UMass Chan Medical School, Lincoln, RI, United States
| | - Kate Schmitter
- Imaging and Radiation Oncology Core-Rhode Island, Department of Radiation Oncology, UMass Chan Medical School, Lincoln, RI, United States
| | - Fred Prior
- Department of Biomedical Informatics, University of Arkansas, Little Rock, AR, United States
| | - Joel Saltz
- Department of Biomedical Informatics, Stony Brook University, Stony Brook, NY, United States
| | - Ashish Sharma
- Department of Biomedical Informatics, Emory University, Atlanta, GA, United States
| | - Maryann Bishop-Jodoin
- Imaging and Radiation Oncology Core-Rhode Island, Department of Radiation Oncology, UMass Chan Medical School, Lincoln, RI, United States
| | - Janaki Moni
- Imaging and Radiation Oncology Core-Rhode Island, Department of Radiation Oncology, UMass Chan Medical School, Lincoln, RI, United States
| | - M. Giulia Cicchetti
- Imaging and Radiation Oncology Core-Rhode Island, Department of Radiation Oncology, UMass Chan Medical School, Lincoln, RI, United States
| | - Thomas J. FitzGerald
- Imaging and Radiation Oncology Core-Rhode Island, Department of Radiation Oncology, UMass Chan Medical School, Lincoln, RI, United States
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14
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Taylor PA, Miles E, Hoffmann L, Kelly SM, Kry SF, Sloth Møller D, Palmans H, Akbarov K, Aznar MC, Clementel E, Corning C, Effeney R, Healy B, Moore A, Nakamura M, Patel S, Shaw M, Stock M, Lehmann J, Clark CH. Prioritizing clinical trial quality assurance for photons and protons: A failure modes and effects analysis (FMEA) comparison. Radiother Oncol 2023; 182:109494. [PMID: 36708923 DOI: 10.1016/j.radonc.2023.109494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 01/13/2023] [Accepted: 01/18/2023] [Indexed: 01/27/2023]
Abstract
BACKGROUND AND PURPOSE The Global Clinical Trials RTQA Harmonization Group (GHG) set out to evaluate and prioritize clinical trial quality assurance. METHODS The GHG compiled a list of radiotherapy quality assurance (QA) tests performed for proton and photon therapy clinical trials. These tests were compared between modalities to assess whether there was a need for different types of assessments per modality. A failure modes and effects analysis (FMEA) was performed to assess the risk of each QA failure. RESULTS The risk analysis showed that proton and photon therapy shared four out of five of their highest-risk failures (end-to-end anthropomorphic phantom test, phantom tests using respiratory motion, pre-treatment patient plan review of contouring/outlining, and on-treatment/post-treatment patient plan review of dosimetric coverage). While similar trends were observed, proton therapy had higher risk failures, driven by higher severity scores. A sub-analysis of occurrence × severity scores identified high-risk scores to prioritize for improvements in RTQA detectability. A novel severity scaler was introduced to account for the number of patients affected by each failure. This scaler did not substantially alter the ranking of tests, but it elevated the QA program evaluation to the top 20th percentile. This is the first FMEA performed for clinical trial quality assurance. CONCLUSION The identification of high-risk errors associated with clinical trials is valuable to prioritize and reduce errors in radiotherapy and improve the quality of trial data and outcomes, and can be applied to optimize clinical radiotherapy QA.
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Affiliation(s)
- Paige A Taylor
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA; The Imaging and Radiation Oncology Core, USA.
| | - Elizabeth Miles
- National Radiotherapy Trials Quality Assurance (RTTQA) Group, Mount Vernon Cancer Centre, Northwood, UK
| | - Lone Hoffmann
- Department of Medical Physics, Aarhus University Hospital, Aarhus, Denmark; Department of Clinical Medicine, Faculty of Health Sciences, Aarhus University, Aarhus, Denmark
| | - Sarah M Kelly
- SIOP Europe, The European Society for Paediatric Oncology, Clos Chapelle-aux-Champs 30, Brussels, Belgium; EORTC Headquarters, European Organisation for Research and Treatment of Cancer, Avenue E. Mounier 83, Brussels, Belgium; Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - Stephen F Kry
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA; The Imaging and Radiation Oncology Core, USA
| | - Ditte Sloth Møller
- Department of Medical Physics, Aarhus University Hospital, Aarhus, Denmark; Department of Clinical Medicine, Faculty of Health Sciences, Aarhus University, Aarhus, Denmark
| | - Hugo Palmans
- MedAustron Ion Therapy Center, Wiener Neustadt, Austria; Metrology for Medical Physics, National Physical Laboratory, Teddington, UK
| | - Kamal Akbarov
- Division of Human Health, Department of Nuclear Sciences and Applications, IAEA, Vienna, Austria
| | - Marianne C Aznar
- Division of Cancer Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Enrico Clementel
- EORTC Headquarters, European Organisation for Research and Treatment of Cancer, Avenue E. Mounier 83, Brussels, Belgium
| | - Coreen Corning
- EORTC Headquarters, European Organisation for Research and Treatment of Cancer, Avenue E. Mounier 83, Brussels, Belgium
| | | | - Brendan Healy
- Australian Clinical Dosimetry Service, ARPANSA, Melbourne, Australia
| | | | - Mitsuhiro Nakamura
- Department of Advanced Medical Physics, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Samir Patel
- Division of Radiation Oncology, Department of Oncology, University of Alberta, Edmonton, Alberta, Canada
| | - Maddison Shaw
- Australian Clinical Dosimetry Service, ARPANSA, Melbourne, Australia; School of Health and Biomedical Sciences, RMIT University, Melbourne, Australia
| | - Markus Stock
- MedAustron Ion Therapy Center, Wiener Neustadt, Austria; Karl Landsteiner University for Health Sciences, Austria
| | - Joerg Lehmann
- TROG Cancer Research, Newcastle, Australia; Department of Radiation Oncology, Calvary Mater Newcastle, Newcastle, Australia; School of Information and Physical Sciences, University of Newcastle, Newcastle, Australia; Institute of Medical Physics, University of Sydney, Sydney, Australia
| | - Catharine H Clark
- Metrology for Medical Physics, National Physical Laboratory, Teddington, UK; National Radiotherapy Trials Quality Assurance (RTTQA) Group, Mount Vernon Cancer Centre, Northwood, UK; Radiotherapy Physics, University College London Hospital, London, UK; Medical Physics and Bioengineering Department, University College London, London, UK
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15
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Lim SB, Tang G. Evaluation of OrthoChromic OC-1 films for photon radiotherapy application. JOURNAL OF RADIATION RESEARCH 2023; 64:105-112. [PMID: 36453442 PMCID: PMC9855338 DOI: 10.1093/jrr/rrac080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 10/07/2022] [Indexed: 06/17/2023]
Abstract
A new film dosimetry system consists of the new OrthoChromic™ OC-1 film, and a novel calibration procedure was evaluated. Two films, C1 and C2, were exposed simultaneously using the 6FFF beam with a step-wedge pattern of five steps ranging from 590 to 3000 cGy. C1 was used for calibration, and C2 was used for calibration curve validation. The second scan of C2 was done by rotating the film by 90-deg. To evaluate the effectiveness of the non-uniform scanner response correction with the new system, a film was exposed to a 20 × 20 cm2 field. The beam profile measured with the film was compared to the IBA cc04 measurements in water. Films were irradiated to characterize the energy response, dynamic range and temporal growth effect. Open (MLC-defined) and clinical fields were radiated to evaluate the overall performance of the new system. The new calibration procedure was validated with an average dose difference of 1.6% and a gamma (2%,2 mm) passing rate of 100%. With C2 scanned 90-deg rotated, the average dose difference was 1.3%. The average difference between cc04 and film was 0.4%. The St between films and diode/cc04 were within -0.3% difference for 1 × 1 to 14 × 14 cm2 and -2.8% for 0.5 × 0.5 cm2. For clinical fields, the average gamma (3%,2 mm) was 98.8%. These results were consistent with EBT3 film and MapCheck measurements with a dose > 400 cGy. The results have shown that the OC-1 film system can achieve accurate results for QA measurements, but more considerable uncertainty was observed within the low dose range.
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Affiliation(s)
- Seng Boh Lim
- Corresponding author. Department of Medical Physics, Memorial Sloan Kettering Cancer Center, 1275 York Ave, New York, New York 10065, USA. E-mail:
| | - Grace Tang
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, 1275 York Ave, New York, New York 10065, USA
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16
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Evaluation of patients’ and occupational radiation risk dose during conventional and interventional radiology procedures. Radiat Phys Chem Oxf Engl 1993 2023. [DOI: 10.1016/j.radphyschem.2023.110818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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17
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Goto S, Hayashi H, Yamaguchi H, Sekiguchi H, Akino R, Shimizu M. Signal-stabilized Al2O3:C-OSL dosimeter “checking chip” for correcting OSL reader sensitivity variation. RADIAT MEAS 2022. [DOI: 10.1016/j.radmeas.2022.106893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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18
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Safwan Ahmad Fadzil M, Mohd Noor N, Ngie Min U, Abdullah N, Taufik Dolah M, Pawanchek M, Andrew Bradley D. Dosimetry audit for megavoltage photon beams applied in non-reference conditions. Phys Med 2022; 100:99-104. [PMID: 35779357 DOI: 10.1016/j.ejmp.2022.06.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Revised: 06/12/2022] [Accepted: 06/13/2022] [Indexed: 11/19/2022] Open
Abstract
PURPOSE We have conducted for the first time a Malaysian postal dosimetry audit of external beam under non-reference conditions by evaluating the output performance while screening for systematic errors within the dosimetry chain. The potential use from the choice of detector were investigated along with the search for other sources of discrepancies. METHODS Ten radiotherapy centres were audited, encompassing 16 megavoltage photon beam arrangements, adopting the IAEA postal dosimetry protocol for non-reference conditions, with a holder modified to accommodate three TLD types: Ge-doped cylindrical silica fibres (CF), Ge-doped flat silica fibres (FF), and TLD-100 powder. RESULTS Eight of the centres operated within ± 5% of stated dose, one other exceeding tolerance for all measured points, and one did not return any dosimeters for analysis after failing the initial irradiations. Post remedial measures, the mean relative response for CF, FF, and TLD-100 was 1.00, 0.99, and 0.98 respectively, with associated coefficients of variation 6.87%, 6.45%, and 5.06%. CONCLUSION High quality radiotherapy clinical practice postal dosimetry audits that are based on sensitive TLDs are seen to be particularly effective in identifying and resolving dose delivery discrepancies.
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Affiliation(s)
- Muhammad Safwan Ahmad Fadzil
- Department of Radiology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia; Diagnostic Imaging and Radiotherapy Program, Centre for Diagnostic, Therapeutic and Investigative Studies, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, 50300 Kuala Lumpur, Malaysia
| | - Noramaliza Mohd Noor
- Department of Radiology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia.
| | - Ung Ngie Min
- Clinical Oncology Unit, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Norhayati Abdullah
- Radiation Safety and Health Division, Malaysian Nuclear Agency, Bangi, 43000 Kajang, Selangor, Malaysia
| | - Mohd Taufik Dolah
- Radiation Safety and Health Division, Malaysian Nuclear Agency, Bangi, 43000 Kajang, Selangor, Malaysia
| | - Mahzom Pawanchek
- Department of Radiotherapy and Oncology, National Cancer Institute, 62250 W.P. Putrajaya, Malaysia
| | - David Andrew Bradley
- Centre for Applied Physics and Radiation Technologies, School of Engineering and Technology, Sunway University, 47500 Petaling Jaya, Selangor, Malaysia; Department of Physics, University of Surrey, Guildford, Surrey GU2 7XH, United Kingdom
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19
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Abdullah N, Bradley D, Nisbet A, Kamarul Zaman Z, Deraman S, Mohd Noor N. Dosimetric characteristics of fabricated germanium doped optical fibres for a postal audit of therapy electron beams. Radiat Phys Chem Oxf Engl 1993 2022. [DOI: 10.1016/j.radphyschem.2022.110346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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20
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Yoon SW, Lin H, Mihailidis D, Kennedy C, Li T. Technical Note: Sources of systemic error in TBI and TSET in-vivo measurements using NanoDot OSLDs within high-efficiency clinics. Med Phys 2022; 49:3489-3496. [PMID: 35213731 DOI: 10.1002/mp.15571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 01/09/2022] [Accepted: 02/13/2022] [Indexed: 11/10/2022] Open
Abstract
PURPOSE To identify sources of systemic errors and estimate their effects, especially the vendor-provided sensitivity Ss,i,vendor , on total body irradiation (TBI) and total skin electron therapy (TSET) in-vivo OSLD measurements. MATERIALS Calibration nanoDot OSLDs were irradiated 50∼300cGy under reference conditions. Raw OSLD readings Mraw were corrected by Ss,i,vendor to obtain corrected readings Mcorr . A quadratic calibration curve relating Mcorr to delivered dose Dw was established and commissioned for clinical use. For clinical measurements, directly adjacent pairs of nanoDot OSLDs were placed on TBI and TSET patients with a medical tape with or without 1.5cm of bolus respectively before treatment. Used OSLDs were bleached between each use until cumulative dose of 15Gy. Relative difference in corrected counts (∆Mcorr,rel =pair-difference/mean) was fitted multi-linearly versus possible sources of systemic errors (Ss,i,vendor , bleaching history, cumulative dose, and age differences). Total of 101 TBI and 110 TSET measurement pairs from calibrated batches were analyzed. RESULTS Ss,i,vendor introduced a residual systemic error to corrected readings Mcorr (-0.98% per +0.01, p = 4e-12). Given Ss,i,vendor distribution is σ = ±0.025, measured dose 1-σ error is ±2.5%, compared to ±2.8% uncertainty reported in the literature which may include this systemic error. Bleaching or cumulative dose did not affect Mcorr significantly after adjusting for Ss,i,vendor . Adjusting for the systemic error in Ss,i,vendor decreased two-sample mean Dw median absolute error from ±2.6% to ±1.9% and 95-percentile absolute error from ±7.1% to ±5.5%. Variability between paired clinical OSLDs was larger for TBI versus TSET at σpd = ±4.7% and ±6.3% respectively, despite similar predictor distributions. CONCLUSION Our findings suggest Mraw correction via vendor-provided sensitivity results in a small but significant systemic error. Dosimeters with outlier sensitivities should be excluded during batch calibration to minimize error. Bleaching and cumulative dose likely minimally affect measurements if cumulative dose is controlled below 15Gy. Random errors were higher for TSET than TBI. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Suk Whan Yoon
- Department of Radiation Oncology, University of Pennsylvania, 3400 Civic Center Boulevard, Philadelphia, Pennsylvania, 19104, USA
| | - Hui Lin
- Department of Radiation Oncology, University of California San Francisco, 505 Parnassus Ave, San Francisco, California, 94143, USA
| | - Dimitris Mihailidis
- Department of Radiation Oncology, University of Pennsylvania, 3400 Civic Center Boulevard, Philadelphia, Pennsylvania, 19104, USA
| | - Christopher Kennedy
- Department of Radiation Oncology, University of Pennsylvania, 3400 Civic Center Boulevard, Philadelphia, Pennsylvania, 19104, USA
| | - Taoran Li
- Department of Radiation Oncology, University of Pennsylvania, 3400 Civic Center Boulevard, Philadelphia, Pennsylvania, 19104, USA
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Yukihara E, Christensen J, Togno M. Demonstration of an optically stimulated luminescence (OSL) material with reduced quenching for proton therapy dosimetry: MgB4O7:Ce,Li. RADIAT MEAS 2022. [DOI: 10.1016/j.radmeas.2022.106721] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Tiwari B, Chaudhary RK, Srivastava A, Kumar R, Sonawane M. Tissue-equivalent dosimeters based on copper doped lithium tetraborate single crystals for radiotherapy. RADIAT MEAS 2022. [DOI: 10.1016/j.radmeas.2022.106704] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Tyagi N, Subashi E, Michael Lovelock D, Kry S, Alvarez PE, Hunt MA, Lim SB. Dosimetric evaluation of irradiation geometry and potential air gaps in an acrylic miniphantom used for external audit of absolute dose calibration for a hybrid 1.5 T MR-linac system. J Appl Clin Med Phys 2021; 23:e13503. [PMID: 34914175 PMCID: PMC8833292 DOI: 10.1002/acm2.13503] [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: 08/09/2021] [Revised: 10/21/2021] [Accepted: 11/30/2021] [Indexed: 11/20/2022] Open
Abstract
Introduction To investigate the impact of partial lateral scatter (LS), backscatter (BS) and presence of air gaps on optically stimulated luminescence dosimeter (OSLD) measurements in an acrylic miniphantom used for dosimetry audit on the 1.5 T magnetic resonance‐linear accelerator (MR‐linac) system. Methods The following irradiation geometries were investigated using OSLDs, A26 MR/A12 MR ion chamber (IC), and Monaco Monte Carlo system: (a) IC/OSLD in an acrylic miniphantom (partial LS, partial BS), (b) IC/OSLD in a miniphantom placed on a solid water (SW) stack at a depth of 1.5 cm (partial LS, full BS), (c) IC/OSLD placed at a depth of 1.5 cm inside a 3 cm slab of SW/buildup (full LS, partial BS), and (d) IC/OSLD centered inside a 3 cm slab of SW/buildup at a depth of 1.5 cm placed on top of a SW stack (full LS, full BS). Average of two irradiated OSLDs with and without water was used at each setup. An air gap of 1 and 2 mm, mimicking presence of potential air gap around the OSLDs in the miniphantom geometry was also simulated. The calibration condition of the machine was 1 cGy/MU at SAD = 143.5 cm, d = 5 cm, G90, and 10 × 10 cm2. Results The Monaco calculation (0.5% uncertainty and 1.0 mm voxel size) for the four setups at the measurement point were 108.2, 108.1, 109.4, and 110.0 cGy. The corresponding IC measurements were 109.0 ± 0.03, 109.5 ± 0.06, 110.2 ± 0.02, and 109.8 ± 0.03 cGy. Without water, OSLDs measurements were ∼10% higher than the expected. With added water to minimize air gaps, the measurements were significantly improved to within 2.2%. The dosimetric impacts of 1 and 2 mm air gaps were also verified with Monaco to be 13.3% and 27.9% higher, respectively, due to the electron return effect. Conclusions A minimal amount of air around or within the OSLDs can cause measurement discrepancies of 10% or higher when placed in a high b‐field MR‐linac system. Care must be taken to eliminate the air from within and around the OSLD.
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Affiliation(s)
- Neelam Tyagi
- Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York, USA
| | - Ergys Subashi
- Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York, USA
| | - Dale Michael Lovelock
- Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York, USA
| | - Stephen Kry
- Department of Radiation Physics, IROC, MD Anderson Cancer Center, Houston, Texas, USA
| | - Paola Elisa Alvarez
- Department of Radiation Physics, IROC, MD Anderson Cancer Center, Houston, Texas, USA
| | - Margie A Hunt
- Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York, USA
| | - Seng Boh Lim
- Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York, USA
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Lim SB, LoSasso T, Chan M, Cervino L, Lovelock DM. Risk Management of Clinical Reference Dosimetry of a Large Hospital Network Using Statistical Process Control. ACTA ACUST UNITED AC 2021; 10:119-131. [PMID: 34395105 PMCID: PMC8360384 DOI: 10.4236/ijmpcero.2021.103011] [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] [Indexed: 12/04/2022]
Abstract
Managing TG-51 reference dosimetry in a large hospital network can be a challenging task. The objectives of this study are to investigate the effectiveness of using Statistical Process Control (SPC) to manage TG-51 workflow in such a network. All the sites in the network performed the annual reference dosimetry in water according to TG-51. These data were used to cross-calibrate the same ion chambers in plastic phantoms for monthly QA output measurements. An energy-specific dimensionless beam quality cross-calibration factor, kqnSW, was derived to monitor the process across multiple sites. The SPC analysis was then performed to obtain the mean, 〈kqnSW〉, standard deviation, σk, the Upper Control Limit (UCL) and Lower Control Limit (LCL) in each beam. This process was first applied to 15 years of historical data at the main campus to assess the effectiveness of the process. A two-year prospective study including all 30 linear accelerators spread over the main campus and seven satellites in the network followed. The ranges of the control limits (±3σ) were found to be in the range of 1.7% – 2.6% and 3.3% – 4.2% for the main campus and the satellite sites respectively. The wider range in the satellite sites was attributed to variations in the workflow. Standardization of workflow was also found to be effective in narrowing the control limits. The SPC is effective in identifying variations in the workflow and was shown to be an effective tool in managing large network reference dosimetry.
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Affiliation(s)
- Seng-Boh Lim
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, USA
| | - Thomas LoSasso
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, USA
| | - Maria Chan
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, USA
| | - Laura Cervino
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, USA
| | - Dale Michael Lovelock
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, USA
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Mizuno H, Yamashita W, Okuyama H, Takase N, Tohyama N, Shimizu H, Fujita Y, Kito S, Nakaji T, Fukuda S. Dose response of a radiophotoluminescent glass dosimeter for TomoTherapy, CyberKnife, and flattening-filter-free linear accelerator output measurements in dosimetry audit. Phys Med 2021; 88:91-97. [PMID: 34214838 DOI: 10.1016/j.ejmp.2021.06.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 05/11/2021] [Accepted: 06/04/2021] [Indexed: 11/19/2022] Open
Abstract
PURPOSE We experimentally determined the radiophotoluminescent glass dosimeter (RPLD) dose responses for TomoTherapy, CyberKnife, and flattening-filter-free (FFF) linear accelerator (linac) outputs for dosimetry audits in Japan. METHODS A custom-made solid phantom with a narrow central-axis spacing of three RPLD elements was used for output measurement to minimise the dose-gradient effect of the non-flattening filter beams. For RPLD dose estimation, we used the ISO 22127 formalism. Additional unit-specific correction factors were introduced and determined via the measured data. For TomoTherapy (7 units) and CyberKnife (4 units), the doses were measured under machine-specific reference fields. For FFF linac (5 units), in addition to the reference condition, we obtained the field-size effects for the range from 5×5 cm to 25×25 cm. RESULTS The correction factors were estimated as 1.008 and 0.999 for TomoTherapy and CyberKnife, respectively. For FFF linac, they ranged from 1.011 to 0.988 for 6 MV and from 1.011 to 0.997 for 10 MV as a function of the side length of the square field from 5 to 25 cm. The estimated uncertainties of the absorbed dose to water measured by RPLD for the units were 1.32%, 1.35%, and 1.30% for TomoTherapy, CyberKnife, and FFF linac, respectively. A summary of the dosimetry audits of these treatment units using the obtained correction factors is also presented. The average percentage differences between the measured and hospital-stated doses were <1% under all conditions. CONCLUSION RPLD can be successfully used as a dosimetry audit tool for modern treatment units.
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Affiliation(s)
- Hideyuki Mizuno
- QST Hospital, National Institutes for Quantum and Radiological Science and Technology, Japan.
| | | | | | | | - Naoki Tohyama
- Tokyo Bay Advanced Imaging & Radiation Oncology Makuhari Clinic, Japan
| | | | | | - Satoshi Kito
- Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, Japan; Graduate School of Medicine, Kyoto University, Japan
| | - Taku Nakaji
- QST Hospital, National Institutes for Quantum and Radiological Science and Technology, Japan
| | - Shigekazu Fukuda
- QST Hospital, National Institutes for Quantum and Radiological Science and Technology, Japan
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Das IJ, Francescon P, Moran JM, Ahnesjö A, Aspradakis MM, Cheng CW, Ding GX, Fenwick JD, Saiful Huq M, Oldham M, Reft CS, Sauer OA. Report of AAPM Task Group 155: Megavoltage photon beam dosimetry in small fields and non-equilibrium conditions. Med Phys 2021; 48:e886-e921. [PMID: 34101836 DOI: 10.1002/mp.15030] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 05/06/2021] [Accepted: 06/02/2021] [Indexed: 12/14/2022] Open
Abstract
Small-field dosimetry used in advance treatment technologies poses challenges due to loss of lateral charged particle equilibrium (LCPE), occlusion of the primary photon source, and the limited choice of suitable radiation detectors. These challenges greatly influence dosimetric accuracy. Many high-profile radiation incidents have demonstrated a poor understanding of appropriate methodology for small-field dosimetry. These incidents are a cause for concern because the use of small fields in various specialized radiation treatment techniques continues to grow rapidly. Reference and relative dosimetry in small and composite fields are the subject of the International Atomic Energy Agency (IAEA) dosimetry code of practice that has been published as TRS-483 and an AAPM summary publication (IAEA TRS 483; Dosimetry of small static fields used in external beam radiotherapy: An IAEA/AAPM International Code of Practice for reference and relative dose determination, Technical Report Series No. 483; Palmans et al., Med Phys 45(11):e1123, 2018). The charge of AAPM task group 155 (TG-155) is to summarize current knowledge on small-field dosimetry and to provide recommendations of best practices for relative dose determination in small megavoltage photon beams. An overview of the issue of LCPE and the changes in photon beam perturbations with decreasing field size is provided. Recommendations are included on appropriate detector systems and measurement methodologies. Existing published data on dosimetric parameters in small photon fields (e.g., percentage depth dose, tissue phantom ratio/tissue maximum ratio, off-axis ratios, and field output factors) together with the necessary perturbation corrections for various detectors are reviewed. A discussion on errors and an uncertainty analysis in measurements is provided. The design of beam models in treatment planning systems to simulate small fields necessitates special attention on the influence of the primary beam source and collimating devices in the computation of energy fluence and dose. The general requirements for fluence and dose calculation engines suitable for modeling dose in small fields are reviewed. Implementations in commercial treatment planning systems vary widely, and the aims of this report are to provide insight for the medical physicist and guidance to developers of beams models for radiotherapy treatment planning systems.
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Affiliation(s)
- Indra J Das
- Department of Radiation Oncology, Northwestern Memorial Hospital, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Paolo Francescon
- Department of Radiation Oncology, Ospedale Di Vicenza, Vicenza, Italy
| | - Jean M Moran
- Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY, USA
| | - Anders Ahnesjö
- Medical Radiation Sciences, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Maria M Aspradakis
- Institute of Radiation Oncology, Cantonal Hospital of Graubünden, Chur, Switzerland
| | - Chee-Wai Cheng
- Department of Radiation Oncology, University Hospitals Cleveland Medical Center, Cleveland, OH, USA
| | - George X Ding
- Department of Radiation Oncology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - John D Fenwick
- Molecular and Clinical Cancer Medicine, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, UK
| | - M Saiful Huq
- Department of Radiation Oncology, University of Pittsburgh, School of Medicine and UPMC Hillman Cancer Center, Pittsburgh, PA, USA
| | - Mark Oldham
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC, USA
| | - Chester S Reft
- Department of Radiation Oncology, University of Chicago, Chicago, IL, USA
| | - Otto A Sauer
- Department of Radiation Oncology, Klinik fur Strahlentherapie, University of Würzburg, Würzburg, Germany
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Application of optically stimulated luminescence in tandem systems for diagnostic radiology. Radiat Phys Chem Oxf Engl 1993 2021. [DOI: 10.1016/j.radphyschem.2021.109354] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Souza L, Nolasco A, Barrera G, Campos W, Souza D, Nogueira M. Evaluation of MgB4O7:Ce, Li and Ce-doped 80MgB2O4–20MgB4O7 as alternative OSL materials for use in quality assurance of 6 MV photon beams. Radiat Phys Chem Oxf Engl 1993 2021. [DOI: 10.1016/j.radphyschem.2021.109355] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Araki F. Monte Carlo determination of a nanoDot OSLD response using quality index for diagnostic kilovoltage X-ray beams. Phys Med 2021; 84:101-108. [PMID: 33887616 DOI: 10.1016/j.ejmp.2021.03.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 03/22/2021] [Accepted: 03/29/2021] [Indexed: 11/17/2022] Open
Abstract
PURPOSE This study aims to investigate the energy response of an optically stimulated luminescent dosimeter known as nanoDot for diagnostic kilovoltage X-ray beams via Monte Carlo calculations. METHODS The nanoDot response is calculated as a function of X-ray beam quality in free air and on a water phantom surface using Monte Carlo simulations. The X-ray fluence spectra are classified using the quality index (QI), which is defined as the ratio of the effective energy to the maximum energy of the photons. The response is calculated for X-ray fluence spectra with QIs of 0.4, 0.5, and 0.6 with tube voltages of 50-137.6 kVp and monoenergetic photon beams. The surface dose estimated using the calculated response is verified by comparing it with that measured using an ionization chamber. RESULTS The nanoDot response in free air for monoenergetic photon beams (QI = 1.0) varies significantly at photon energies below 100 keV and reaches a factor of 3.6 at 25-30 keV. The response differs by up to approximately 6% between QIs of 0.4 and 0.6 for the same half-value layer (HVL). The response at the phantom surface decreases slightly owing to the backscatter effect, and it is almost independent of the field size. The agreement between the surface dose estimated using the nanoDot and that measured using the ionization chamber for assessing X-ray beam qualities is less than 2%. CONCLUSIONS The nanoDot response is indicated as a function of HVL for the specified QIs, and it enables the direct surface dose measurement.
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Affiliation(s)
- Fujio Araki
- Department of Health Sciences, Faculty of Life Sciences, Kumamoto University, 4-24-1 Kuhonji, Chuo-ku, Kumamoto 862-0976, Japan.
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Yukihara EG, Kron T. APPLICATIONS OF OPTICALLY STIMULATED LUMINESCENCE IN MEDICAL DOSIMETRY. RADIATION PROTECTION DOSIMETRY 2020; 192:122-138. [PMID: 33412585 DOI: 10.1093/rpd/ncaa213] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 11/15/2020] [Accepted: 11/23/2020] [Indexed: 06/12/2023]
Abstract
If the first decade of the new millennium saw the establishment of a more solid foundation for the use of the Optically Stimulated Luminescence (OSL) in medical dosimetry, the second decade saw the technique take root and become more widely used in clinical studies. Recent publications report not only characterization and feasibility studies of the OSL technique for various applications in radiotherapy and radiology, but also the practical use of OSL for postal audits, estimation of staff dose, in vivo dosimetry, dose verification and dose mapping studies. This review complements previous review papers and reports on the topic, providing a panorama of the new advances and applications in the last decade. Attention is also dedicated to potential future applications, such as LET dosimetry, 2D/3D dosimetry using OSL, dosimetry in magnetic resonance imaging-guided radiotherapy (MRIgRT) and dosimetry of extremely high dose rates (FLASH therapy).
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Affiliation(s)
- Eduardo G Yukihara
- Department of Radiation Safety and Security, Paul Scherrer Institute, 5200 Villigen, Switzerland
| | - Tomas Kron
- Department of Physical Sciences, Peter MacCallum Cancer Centre, 3000 Melbourne, Australia
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Meyer T, Quirk S, Husain S, Hilts M, Crook J, Watt E, Guebert A, Frederick A, Batchelar D, Kry SF, Roumeliotis M. Peer-based credentialing for brachytherapy: Application in permanent seed implant. Brachytherapy 2020; 19:794-799. [DOI: 10.1016/j.brachy.2020.03.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 03/17/2020] [Accepted: 03/26/2020] [Indexed: 11/29/2022]
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Krause F, Möller M, Risske F, Siebert FA. Dosimetry of ruthenium-106 ophthalmic applicators with thin layer thermoluminescence dosimeters - Clinical quality control. Z Med Phys 2020; 30:142-147. [DOI: 10.1016/j.zemedi.2019.11.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 10/23/2019] [Accepted: 11/08/2019] [Indexed: 10/25/2022]
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Ito S, Araki F, Hoshida K, Ohno T. Impact of transverse magnetic fields on dose response of a nanoDot OSLD in megavoltage photon beams. Phys Med 2020; 70:153-160. [PMID: 32028172 DOI: 10.1016/j.ejmp.2020.01.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 01/24/2020] [Accepted: 01/26/2020] [Indexed: 10/25/2022] Open
Abstract
PURPOSE We investigated the impact of transverse magnetic fields on the dose response of a nanoDot optically stimulated luminescence dosimetry (OSLD) in megavoltage photon beams. METHODS The nanoDot OSLD response was calculated via Monte Carlo (MC) simulations. The responses RQ and RQ,B without and with the transverse magnetic fields of 0.35-3 T were analyzed as a function of depth at a 10 cm × 10 cm field for 4-18 MV photons in a solid water phantom. All responses were determined based on comparisons with the response under the reference conditions (depth of 10 cm and a 10 cm × 10 cm field) for 6 MV without the magnetic field. In addition, the influence of air-gaps on the nanoDot response in the magnetic field was estimated according to Burlin's general cavity theory. RESULTS The RQ as a function of depth for 4-18 MV ranged from 1.013 to 0.993, excepting the buildup region. The RQ,B increased from 2.8% to 1.5% at 1.5 T and decreased from 3.0% to 1.1% at 3 T in comparison with RQ as the photon energy increased. The depth dependence of RQ,B was less than 1%, excepting the buildup region. The top air-gap and the bottom air- gap were responsible for the response reduction and the response increase, respectively. CONCLUSIONS The response RQ,B varied depending on the magnetic field intensity, and the variation of RQ,B reduced as the photon beam energy increased. The air-gaps affected the dose deposition in the magnetic fields.
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Affiliation(s)
- Shotaro Ito
- Graduate School of Health Sciences, Kumamoto University, 4-24-1 Kuhonji, Kumamoto, Japan
| | - Fujio Araki
- Department of Health Sciences, Faculty of Life Sciences, Kumamoto University, 4-24-1 Kuhonji, Kumamoto, Japan.
| | - Kento Hoshida
- Graduate School of Health Sciences, Kumamoto University, 4-24-1 Kuhonji, Kumamoto, Japan
| | - Takeshi Ohno
- Department of Health Sciences, Faculty of Life Sciences, Kumamoto University, 4-24-1 Kuhonji, Kumamoto, Japan
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In vivo monitoring of total skin electron dose using optically stimulated luminescence dosimeters. Rep Pract Oncol Radiother 2020; 25:35-40. [PMID: 31889918 DOI: 10.1016/j.rpor.2019.12.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 09/23/2019] [Accepted: 12/09/2019] [Indexed: 11/21/2022] Open
Abstract
Aim This study retrospectively analysed the results of using optically stimulated radiation dosimeters (OSLDs) for in vivo dose measurements during total skin electron therapy (TSET, also known as TSEI, TSEB, TSEBT, TSI or TBE) treatments of patients with mycosis fungoides. Background TSET treatments are generally delivered to standing patients, using treatment plans that are devised using manual dose calculations that require verification via in vivo dosimetry. Despite the increasing use of OSLDs for radiation dosimetry, there is minimal published guidance on the use of OSLDs for TSET verification. Materials and methods This study retrospectively reviewed in vivo dose measurements made during treatments of nine consecutive TSET patients, treated between 2013 and 2018. Landauer nanoDot OSLDs were used to measure the skin dose at reference locations on each patient, as well as at locations of clinical interest such as the head, hands, feet, axilla and groin. Results 1301 OSLD measurements were aggregated and analysed, producing results that were in broad agreement with previous TLD studies, while providing additional information about the variation of dose across concave surfaces and potentially guiding future refinement of treatment setup. In many cases these in vivo measurements were used to identify deviations from the planned dose in reference locations and to identify anatomical regions where additional shielding or boost treatments were required. Conclusions OSLDs can be used to obtain measurements of TSET dose that can inform monitor unit adjustments and identify regions of under and over dosage, while potentially informing continuous quality improvement in TSET treatment delivery.
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Kry SF, Alvarez P, Cygler JE, DeWerd LA, Howell RM, Meeks S, O'Daniel J, Reft C, Sawakuchi G, Yukihara EG, Mihailidis D. AAPM TG 191: Clinical use of luminescent dosimeters: TLDs and OSLDs. Med Phys 2019; 47:e19-e51. [DOI: 10.1002/mp.13839] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 08/27/2019] [Accepted: 08/28/2019] [Indexed: 12/20/2022] Open
Affiliation(s)
- Stephen F. Kry
- The University of Texas MD Anderson Cancer Center Houston TX USA
| | - Paola Alvarez
- The University of Texas MD Anderson Cancer Center Houston TX USA
| | | | | | | | - Sanford Meeks
- University of Florida Health Cancer Center Orlando FL USA
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Naismith O, Mayles H, Bidmead M, Clark CH, Gulliford S, Hassan S, Khoo V, Roberts K, South C, Hall E, Dearnaley D. Radiotherapy Quality Assurance for the CHHiP Trial: Conventional Versus Hypofractionated High-Dose Intensity-Modulated Radiotherapy in Prostate Cancer. Clin Oncol (R Coll Radiol) 2019; 31:611-620. [PMID: 31201110 DOI: 10.1016/j.clon.2019.05.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 04/01/2019] [Accepted: 04/12/2019] [Indexed: 10/26/2022]
Abstract
AIMS The CHHiP trial investigated the use of moderate hypofractionation for the treatment of localised prostate cancer using intensity-modulated radiotherapy (IMRT). A radiotherapy quality assurance programme was developed to assess compliance with treatment protocol and to audit treatment planning and dosimetry of IMRT. This paper considers the outcome and effectiveness of the programme. MATERIALS AND METHODS Quality assurance exercises included a pre-trial process document and planning benchmark cases, prospective case reviews and a dosimetry site visit on-trial and a post-trial feedback questionnaire. RESULTS In total, 41 centres completed the quality assurance programme (37 UK, four international) between 2005 and 2010. Centres used either forward-planned (field-in-field single phase) or inverse-planned IMRT (25 versus 17). For pre-trial quality assurance exercises, 7/41 (17%) centres had minor deviations in their radiotherapy processes; 45/82 (55%) benchmark plans had minor variations and 17/82 (21%) had major variations. One hundred prospective case reviews were completed for 38 centres. Seventy-one per cent required changes to clinical outlining pre-treatment (primarily prostate apex and base, seminal vesicles and penile bulb). Errors in treatment planning were reduced relative to pre-trial quality assurance results (49% minor and 6% major variations). Dosimetry audits were conducted for 32 centres. Ion chamber dose point measurements were within ±2.5% in the planning target volume and ±8% in the rectum. 28/36 films for combined fields passed gamma criterion 3%/3 mm and 11/15 of IMRT fluence film sets passed gamma criterion 4%/4 mm using a 98% tolerance. Post-trial feedback showed that trial participation was beneficial in evolving clinical practice and that the quality assurance programme helped some centres to implement and audit prostate IMRT. CONCLUSION Overall, quality assurance results were satisfactory and the CHHiP quality assurance programme contributed to the success of the trial by auditing radiotherapy treatment planning and protocol compliance. Quality assurance supported the introduction of IMRT in UK centres, giving additional confidence and external review of IMRT where it was a newly adopted technique.
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Affiliation(s)
- O Naismith
- Royal Marsden NHS Foundation Trust, London, UK.
| | - H Mayles
- Clatterbridge Cancer Centre, Bebington, Wirral, UK
| | - M Bidmead
- Royal Marsden NHS Foundation Trust, London, UK
| | - C H Clark
- Royal Surrey County Hospital, Guildford, UK
| | - S Gulliford
- The Institute of Cancer Research, London, UK
| | - S Hassan
- The Institute of Cancer Research, London, UK
| | - V Khoo
- Royal Marsden NHS Foundation Trust, London, UK; The Institute of Cancer Research, London, UK
| | - K Roberts
- Royal Marsden NHS Foundation Trust, London, UK
| | - C South
- Royal Surrey County Hospital, Guildford, UK
| | - E Hall
- The Institute of Cancer Research, London, UK
| | - D Dearnaley
- Royal Marsden NHS Foundation Trust, London, UK; The Institute of Cancer Research, London, UK
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Tsai HY, Sung CH, Chen HH, Lin MW, Huang HC, Chang SL. Clinical application of ionization density dependence of the glow curve for measuring linear energy transfer in therapeutic proton beams. RADIAT MEAS 2019. [DOI: 10.1016/j.radmeas.2019.106146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Hoshida K, Araki F, Ohno T, Kobayashi I. Response of a nanoDot OSLD system in megavoltage photon beams. Phys Med 2019; 64:74-80. [DOI: 10.1016/j.ejmp.2019.06.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 06/16/2019] [Accepted: 06/25/2019] [Indexed: 11/29/2022] Open
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Tendler II, Bredfeldt JS, Zhang R, Bruza P, Jermyn M, Pogue BW, Gladstone DJ. Technical Note: Quality assurance and relative dosimetry testing of a 60 Co total body irradiator using optical imaging. Med Phys 2019; 46:3674-3678. [PMID: 31152565 DOI: 10.1002/mp.13637] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 05/15/2019] [Accepted: 05/28/2019] [Indexed: 11/07/2022] Open
Abstract
PURPOSE The aim of this study was to create an optical imaging-based system for quality assurance (QA) testing of a dedicated Co-60 total body irradiation (TBI) machine. Our goal is to streamline the QA process by minimizing the amount time necessary for tests such as verification of dose rate and field homogeneity. METHODS Plastic scintillating rods were placed directly on the patient treatment couch of a dedicated TBI 60 Co irradiator. A tripod-mounted intensified camera was placed directly adjacent to the couch. Images were acquired over a 30-s period once the cobalt source was fully exposed. Real-time image filtering was used; cumulative images were flatfield corrected as well as background and darkfield subtracted. Scintillators were used to measure light-radiation field correspondence, dose rate, field homogeneity, and symmetry. Dose rate effects were measured by modifying the height of the treatment couch and scintillator response was compared to ionization chamber (IC) measurements. Optically stimulated luminesce detector (OSLD) used as reference dosimeters during field symmetry and homogeneity testing. RESULTS The scintillator-based system accurately reported changes in dose rate. When comparing normalized output values for IC vs scintillators over a range of source-to-surface distances, a linear relationship (R2 = 0.99) was observed. Normalized scintillator signal matched OSLD measurements with <1.5% difference during field homogeneity and symmetry testing. Beam symmetry across both axes of the field was within 2%. The light field was found to correspond to 90 ± 3% of the isodose maximum along the longitudinal and latitudinal axis, respectively. Scintillator imaging output results using a single image stack requiring no postexposure processing (needed for OSLD) or repeat manual measurements (needed for IC). CONCLUSION Imaging of scintillation light emission from plastic rods is a viable and efficient method for carrying out TBI 60 Co irradiator QA. We have shown that this technique can accurately measure field homogeneity, symmetry, light-radiation field correspondence, and dose rate effects.
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Affiliation(s)
- Irwin I Tendler
- Thayer School of Engineering, Dartmouth College, Hanover, NH, USA
| | - Jeremy S Bredfeldt
- Department of Radiation Oncology, Brigham and Women's Hospital, Dana Farber Cancer Institute, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA
| | - Rongxiao Zhang
- Winship Cancer Institute, Emory University, Atlanta, GA, USA
| | - Petr Bruza
- Thayer School of Engineering, Dartmouth College, Hanover, NH, USA.,DoseOptics LLC, Lebanon, NH, USA
| | - Michael Jermyn
- Thayer School of Engineering, Dartmouth College, Hanover, NH, USA.,DoseOptics LLC, Lebanon, NH, USA
| | - Brian W Pogue
- Thayer School of Engineering, Dartmouth College, Hanover, NH, USA.,DoseOptics LLC, Lebanon, NH, USA.,Department of Medicine, Geisel School of Medicine, Dartmouth College, Hanover, NH, USA
| | - David J Gladstone
- Thayer School of Engineering, Dartmouth College, Hanover, NH, USA.,Department of Medicine, Geisel School of Medicine, Dartmouth College, Hanover, NH, USA.,Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, NH, USA
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Scarboro SB, Cody D, Stingo FC, Alvarez P, Followill D, Court L, Zhang D, McNitt‐Gray M, Kry SF. Calibration strategies for use of the nanoDot OSLD in CT applications. J Appl Clin Med Phys 2019; 20:331-339. [PMID: 30426664 PMCID: PMC6333198 DOI: 10.1002/acm2.12491] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 09/26/2018] [Accepted: 10/06/2018] [Indexed: 11/06/2022] Open
Abstract
Aluminum oxide based optically stimulated luminescent dosimeters (OSLD) have been recognized as a useful dosimeter for measuring CT dose, particularly for patient dose measurements. Despite the increasing use of this dosimeter, appropriate dosimeter calibration techniques have not been established in the literature; while the manufacturer offers a calibration procedure, it is known to have relatively large uncertainties. The purpose of this work was to evaluate two clinical approaches for calibrating these dosimeters for CT applications, and to determine the uncertainty associated with measurements using these techniques. Three unique calibration procedures were used to calculate dose for a range of CT conditions using a commercially available OSLD and reader. The three calibration procedures included calibration (a) using the vendor-provided method, (b) relative to a 120 kVp CT spectrum in air, and (c) relative to a megavoltage beam (implemented with 60 Co). The dose measured using each of these approaches was compared to dose measured using a calibrated farmer-type ion chamber. Finally, the uncertainty in the dose measured using each approach was determined. For the CT and megavoltage calibration methods, the dose measured using the OSLD nanoDot was within 5% of the dose measured using an ion chamber for a wide range of different CT scan parameters (80-140 kVp, and with measurements at a range of positions). When calibrated using the vendor-recommended protocol, the OSLD measured doses were on average 15.5% lower than ion chamber doses. Two clinical calibration techniques have been evaluated and are presented in this work as alternatives to the vendor-provided calibration approach. These techniques provide high precision for OSLD-based measurements in a CT environment.
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Affiliation(s)
- Sarah B. Scarboro
- The University of Texas MD Anderson Cancer CenterHoustonTXUSA
- Graduate School of Biomedical SciencesThe University of Texas Health Science Center HoustonHoustonTXUSA
| | - Dianna Cody
- The University of Texas MD Anderson Cancer CenterHoustonTXUSA
- Graduate School of Biomedical SciencesThe University of Texas Health Science Center HoustonHoustonTXUSA
| | - Francesco C. Stingo
- The University of Texas MD Anderson Cancer CenterHoustonTXUSA
- Graduate School of Biomedical SciencesThe University of Texas Health Science Center HoustonHoustonTXUSA
| | - Paola Alvarez
- The University of Texas MD Anderson Cancer CenterHoustonTXUSA
| | - David Followill
- The University of Texas MD Anderson Cancer CenterHoustonTXUSA
- Graduate School of Biomedical SciencesThe University of Texas Health Science Center HoustonHoustonTXUSA
| | - Laurence Court
- The University of Texas MD Anderson Cancer CenterHoustonTXUSA
- Graduate School of Biomedical SciencesThe University of Texas Health Science Center HoustonHoustonTXUSA
| | - Di Zhang
- Biomedical Physics Graduate ProgramDavid Geffen School of Medicine at UCLALos AngelesCAUSA
- Present address:
Toshiba American Medical SystemsTustinCAUSA
| | - Michael McNitt‐Gray
- The Department of Radiological SciencesDavid Geffen School of Medicine at UCLALos AngelesCAUSA
| | - Stephen F. Kry
- The University of Texas MD Anderson Cancer CenterHoustonTXUSA
- Graduate School of Biomedical SciencesThe University of Texas Health Science Center HoustonHoustonTXUSA
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Durante M, Paganetti H, Pompos A, Kry SF, Wu X, Grosshans DR. Report of a National Cancer Institute special panel: Characterization of the physical parameters of particle beams for biological research. Med Phys 2018; 46:e37-e52. [PMID: 30506898 DOI: 10.1002/mp.13324] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 10/28/2018] [Accepted: 11/05/2018] [Indexed: 12/16/2022] Open
Abstract
PURPOSE To define the physical parameters needed to characterize a particle beam in order to allow intercomparison of different experiments performed using different ions at the same facility and using the same ion at different facilities. METHODS At the request of the National Cancer Institute (NCI), a special panel was convened to review the current status of the field and to provide suggested metrics for reporting the physical parameters of particle beams to be used for biological research. A set of physical parameters and measurements that should be performed by facilities and understood and reported by researchers supported by NCI to perform pre-clinical radiobiology and medical physics of heavy ions were generated. RESULTS Standard measures such as radiation delivery technique, beam modifiers used, nominal energy, field size, physical dose and dose rate should all be reported. However, more advanced physical measurements, including detailed characterization of beam quality by microdosimetric spectrum and fragmentation spectra, should also be established and reported. Details regarding how such data should be incorporated into Monte Carlo simulations and the proper reporting of simulation details are also discussed. CONCLUSIONS In order to allow for a clear relation of physical parameters to biological effects, facilities and researchers should establish and report detailed physical characteristics of the irradiation beams utilized including both standard and advanced measures. Biological researchers are encouraged to actively engage facility staff and physicists in the design and conduct of experiments. Modeling individual experimental setups will allow for the reporting of the uncertainties in the measurement or calculation of physical parameters which should be routinely reported.
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Affiliation(s)
- Marco Durante
- Biophysics Department, GSI Helmholtzzentrum für Schwerionenforschung and Technische Universität Darmstadt, Institute of Condensed Matter Physics, Planckstraße 1, 64291, Darmstadt, Germany
| | - Harald Paganetti
- Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA, 02114, USA
| | - Arnold Pompos
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Stephen F Kry
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Xiaodong Wu
- Department of Medical Physics, Shanghai Proton and Heavy Ion Center, Shanghai, China
| | - David R Grosshans
- Departments of Radiation and Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77054, USA
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Kry SF, Peterson CB, Howell RM, Izewska J, Lye J, Clark CH, Nakamura M, Hurkmans C, Alvarez P, Alves A, Bokulic T, Followill D, Kazantsev P, Lowenstein J, Molineu A, Palmer J, Smith SA, Taylor P, Wesolowska P, Williams I. Remote beam output audits: a global assessment of results out of tolerance. PHYSICS & IMAGING IN RADIATION ONCOLOGY 2018; 7:39-44. [PMID: 31872085 PMCID: PMC6927685 DOI: 10.1016/j.phro.2018.08.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Background and purpose Remote beam output audits, which independently measure an institution’s machine calibration, are a common component of independent radiotherapy peer review. This work reviews the results and trends of these audit results across several organisations and geographical regions. Materials and methods Beam output audit results from the Australian Clinical Dosimetry Services, International Atomic Energy Agency, Imaging and Radiation Oncology Core, and Radiation Dosimetry Services were evaluated from 2010 to the present. The rate of audit results outside a ±5% tolerance was evaluated for photon and electron beams as a function of the year of irradiation and nominal beam energy. Additionally, examples of confirmed calibration errors were examined to provide guidance to clinical physicists and auditing bodies. Results Of the 210,167 audit results, 1323 (0.63%) were outside of tolerance. There was a clear trend of improved audit performance for more recent dates, and while all photon energies generally showed uniform rates of results out of tolerance, low (6 MeV) and high (≥18 MeV) energy electron beams showed significantly elevated rates. Twenty nine confirmed calibration errors were explored and attributed to a range of issues, such as equipment failures, errors in setup, and errors in performing the clinical reference calibration. Forty-two percent of these confirmed errors were detected during ongoing periodic monitoring, and not at the time of the first audit of the machine. Conclusions Remote beam output audits have identified, and continue to identify, numerous and often substantial beam calibration errors.
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Affiliation(s)
- Stephen F Kry
- Imaging and Radiation Oncology Core, MD Anderson Cancer Center, Houston USA.,Department of Radiation Physics, MD Anderson Cancer Center, Houston USA
| | | | - Rebecca M Howell
- Department of Radiation Physics, MD Anderson Cancer Center, Houston USA.,Radiation Dosimetry Services, MD Anderson Cancer Center, Houston USA
| | - Joanna Izewska
- Dosimetry Laboratory, Dosimetry and Medical Radiation Physics Section, Division of Human Health, International Atomic Energy Agency, Vienna Austria
| | - Jessica Lye
- Australian Clinical Dosimetry Service, ARPANSA, Melbourne, Australia
| | - Catharine H Clark
- RadioTherapy Trials Quality Assurance Group, Mount Vernon Cancer Centre, London UK.,Metrology for Medical Physics, National Physical Laboratory, Teddington UK.,Department of Medical Physics, Royal Surrey County Hospital, Surrey UK
| | - Mitsuhiro Nakamura
- JCOG Division of Medical Physics, Department of Information Technology and Medical Engineering, Human Health Sciences, Graduate School of Medicine, Kyoto University
| | - Coen Hurkmans
- EORTC Radiation Oncology Group, Brussels, Belgium.,Department of radiation Oncology, Catharina Hospital Eindhoven, The Netherlands
| | - Paola Alvarez
- Imaging and Radiation Oncology Core, MD Anderson Cancer Center, Houston USA.,Department of Radiation Physics, MD Anderson Cancer Center, Houston USA
| | - Andrew Alves
- Australian Clinical Dosimetry Service, ARPANSA, Melbourne, Australia
| | - Tomislav Bokulic
- Dosimetry Laboratory, Dosimetry and Medical Radiation Physics Section, Division of Human Health, International Atomic Energy Agency, Vienna Austria
| | - David Followill
- Imaging and Radiation Oncology Core, MD Anderson Cancer Center, Houston USA.,Department of Radiation Physics, MD Anderson Cancer Center, Houston USA
| | - Pavel Kazantsev
- Dosimetry Laboratory, Dosimetry and Medical Radiation Physics Section, Division of Human Health, International Atomic Energy Agency, Vienna Austria
| | - Jessica Lowenstein
- Imaging and Radiation Oncology Core, MD Anderson Cancer Center, Houston USA.,Department of Radiation Physics, MD Anderson Cancer Center, Houston USA
| | - Andrea Molineu
- Imaging and Radiation Oncology Core, MD Anderson Cancer Center, Houston USA.,Department of Radiation Physics, MD Anderson Cancer Center, Houston USA
| | - Jacob Palmer
- Department of Radiation Physics, MD Anderson Cancer Center, Houston USA.,Radiation Dosimetry Services, MD Anderson Cancer Center, Houston USA
| | - Susan A Smith
- Department of Radiation Physics, MD Anderson Cancer Center, Houston USA.,Radiation Dosimetry Services, MD Anderson Cancer Center, Houston USA
| | - Paige Taylor
- Imaging and Radiation Oncology Core, MD Anderson Cancer Center, Houston USA.,Department of Radiation Physics, MD Anderson Cancer Center, Houston USA
| | - Paulina Wesolowska
- Dosimetry Laboratory, Dosimetry and Medical Radiation Physics Section, Division of Human Health, International Atomic Energy Agency, Vienna Austria
| | - Ivan Williams
- Australian Clinical Dosimetry Service, ARPANSA, Melbourne, Australia
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