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Bouchez Q, Vandenbroucke D, Pittomvils G, Boterberg T, van Eijkeren M, Leblans P, Vanderstraeten B. Computed chest radiography for total body irradiation: image quality and clinical feasibility. Biomed Phys Eng Express 2024; 10:045032. [PMID: 38788700 DOI: 10.1088/2057-1976/ad5018] [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: 03/18/2024] [Accepted: 05/24/2024] [Indexed: 05/26/2024]
Abstract
Objective.In myeloablative total body irradiation (TBI), lung shielding blocks are used to reduce the dose to the lungs and hence decrease the risk of radiation pneumonitis. Some centers are still using mega-Volt (MV) imaging with dedicated silver halide-based films during simulation and treatment for lung delineation and position verification. However, the availability of these films has recently become an issue. This study examines the clinical performance of a computed radiography (CR) solution in comparison to radiographic films and potential improvement of image quality by filtering and post-processing.Approach.We compared BaFBrI-based CR plates to radiographic films. First, images of an aluminum block were analyzed to assess filter impact on scatter reduction. Secondly, a dedicated image quality phantom was used to assess signal linearity, signal-to-noise ratio (SNR), contrast and spatial resolution. Ultimately, a clinical performance study involving two impartial observers was conducted on an anthropomorphic chest phantom, employing visual grading analysis (VGA). Various filter materials and positions as well as post-processing were examined, and the workflow between CR and film was compared.Main results.CR images exhibited high SNR and linearity but demonstrated lower spatial and contrast resolution when compared to film. However, filtering improved contrast resolution and SNR, while positioning filters inside the cassette additionally enhanced sharpness. Image processing improved VGA scores, while additional filtering also resulted in higher spine visibility scores. CR shortened TBI simulation by over 10 minutes for one patient, alongside a dose reduction by order of 0.1 Gy.Significance.This study highlights potential advantages of shifting from conventional radiographic film to CR for TBI. Overall, CR with the incorporation of processing and filtering proves to be suitable for TBI chest imaging. When compared to radiographic film, CR offers advantages such as reduced simulation time and dose delivery, re-usability of image plates and digital workflow integration.
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Affiliation(s)
- Quentin Bouchez
- Department of Human Structure and Repair, Ghent University, Corneel Heymanslaan 10, B-9000 Ghent, Belgium
| | | | - Geert Pittomvils
- Department of Radiotherapy-Oncology, Ghent University Hospital, Corneel Heymanslaan 10, B-9000 Ghent, Belgium
| | - Tom Boterberg
- Department of Human Structure and Repair, Ghent University, Corneel Heymanslaan 10, B-9000 Ghent, Belgium
- Department of Radiotherapy-Oncology, Ghent University Hospital, Corneel Heymanslaan 10, B-9000 Ghent, Belgium
| | - Marc van Eijkeren
- Department of Human Structure and Repair, Ghent University, Corneel Heymanslaan 10, B-9000 Ghent, Belgium
- Department of Radiotherapy-Oncology, Ghent University Hospital, Corneel Heymanslaan 10, B-9000 Ghent, Belgium
| | - Paul Leblans
- R&D Imaging, Agfa N.V., Septestraat 27, B-2640 Mortsel, Belgium
| | - Barbara Vanderstraeten
- Department of Human Structure and Repair, Ghent University, Corneel Heymanslaan 10, B-9000 Ghent, Belgium
- Department of Radiotherapy-Oncology, Ghent University Hospital, Corneel Heymanslaan 10, B-9000 Ghent, Belgium
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Claessens M, Vanreusel V, Gasparini A, Nascimento LDF, Yalvec B, Reniers B, Verellen D. Automated determination of the ion-recombination correction factor (k sat) in ultra-high dose rate electron radiation therapy. Med Phys 2024; 51:4536-4545. [PMID: 38639653 DOI: 10.1002/mp.17085] [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: 04/03/2023] [Revised: 03/06/2024] [Accepted: 03/13/2024] [Indexed: 04/20/2024] Open
Abstract
BACKGROUND Plane-parallel ionization chambers are the recommended secondary standard systems for clinical reference dosimetry of electrons. Dosimetry in high dose rate and dose-per-pulse (DPP) is challenging as ionization chambers are subject to ion recombination, especially when dose rate and/or DPP is increased beyond the range of conventional radiotherapy. The lack of universally accepted models for correction of ion recombination in UDHR is still an issue as it is, especially in FLASH-RT research, which is crucial in order to be able to accurately measure the dose for a wide range of dose rates and DPPs. PURPOSE The objective of this study was to show the feasibility of developing an Artificial Intelligence model to predict the ion-recombination factor-ksat for a plane-parallel Advanced Markus ionization chamber for conventional and ultra-high dose rate electron beams based on machine parameters. In addition, the predicted ksat of the AI model was compared with the current applied analytical models for this correction factor. METHODS A total number of 425 measurements was collected with a balanced variety in machine parameter settings. The specific ksat values were determined by dividing the output of the reference dosimeter (optically stimulated luminescence [OSL]) by the output of the AM chamber. Subsequently, a XGBoost regression model was trained, which used the different machine parameters as input features and the corresponding ksat value as output. The prediction accuracy of this regression model was characterized by R2-coefficient of determination, mean absolute error and root mean squared error. In addition, the model was compared with the Two-Voltage (TVA) method and empirical Petersson model for 19 different dose-per-pulse values ranging from conventional to UDHR regimes. The Akiake Information criterion (AIC) was calculated for the three different models. RESULTS The XGBoost regression model reached a R2-score of 0.94 on the independent test set with a MAE of 0.067 and RMSE of 0.106. For the additional 19 random data points, the ksat values predicted by the XGBoost model showed to be in agreement, within the uncertainties, with the ones determined by the Petersson model and better than the TVA method for doses per pulse >3.5 Gy with a maximum deviation from the ground truth of 14.2%, 16.7%, and -36.0%, respectively, for DPP >4 Gy. CONCLUSION The proposed method of using AI for ksat determination displays efficiency. For the investigated DPPs, the ksat values obtained with the XGBoost model were in concurrence with the ones obtained with the current available analytical models within the boundaries of uncertainty, certainly for the DPP characterizing UDHR. But the overall performance of the AI model, taking the number of free parameters into account, lacked efficiency. Future research should optimize the determination of the experimental ksat, and investigate the determination the ksat for DPPs higher than the ones investigated in this study, while also evaluating the prediction of the proposed XGBoost model for UDHR machines of different centers.
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Affiliation(s)
- Michaël Claessens
- Department of Radiation Oncology, Iridium Netwerk, Wilrijk, Antwerp, Belgium
- Centre for Oncological Research (CORE), Integrated Personalized and Precision Oncology Network (IPPON), University of Antwerp, Antwerp, Belgium
| | - Verdi Vanreusel
- Department of Radiation Oncology, Iridium Netwerk, Wilrijk, Antwerp, Belgium
- Centre for Oncological Research (CORE), Integrated Personalized and Precision Oncology Network (IPPON), University of Antwerp, Antwerp, Belgium
- Research in Dosimetric Applications (RDA), SCK CEN, Mol, Antwerp, Belgium
| | - Alessia Gasparini
- Department of Radiation Oncology, Iridium Netwerk, Wilrijk, Antwerp, Belgium
- Centre for Oncological Research (CORE), Integrated Personalized and Precision Oncology Network (IPPON), University of Antwerp, Antwerp, Belgium
| | | | - Burak Yalvec
- NuTeC, CMK, Hasselt University, Hasselt, Belgium
| | | | - Dirk Verellen
- Department of Radiation Oncology, Iridium Netwerk, Wilrijk, Antwerp, Belgium
- Centre for Oncological Research (CORE), Integrated Personalized and Precision Oncology Network (IPPON), University of Antwerp, Antwerp, Belgium
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De Saint-Hubert M, Caprioli M, de Freitas Nascimento L, Delombaerde L, Himschoot K, Vandenbroucke D, Leblans P, Crijns W. New optically stimulated luminescence dosimetry film optimized for energy dependence guided by Monte Carlo simulations. Phys Med Biol 2024; 69:075005. [PMID: 38394683 DOI: 10.1088/1361-6560/ad2ca2] [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: 10/19/2023] [Accepted: 02/23/2024] [Indexed: 02/25/2024]
Abstract
Optically stimulated luminescence (OSL) film dosimeters, based on BaFBr:Eu2+phosphor material, have major dosimetric advantages such as dose linearity, high spatial resolution, film re-usability, and immediate film readout. However, they exhibit an energy-dependent over-response at low photon energies because they are not made of tissue-equivalent materials. In this work, the OSL energy-dependent response was optimized by lowering the phosphor grain size and seeking an optimal choice of phosphor concentration and film thickness to achieve sufficient signal sensitivity. This optimization process combines measurement-based assessments of energy response in narrow x-ray beams with various energy response calculation methods applied to different film metrics. Theoretical approaches and MC dose simulations were used for homogeneous phosphor distributions and for isolated phosphor grains of different dimensions, where the dose in the phosphor grain was calculated. In total 8 OSL films were manufactured with different BaFBr:Eu2+median particle diameters (D50): 3.2μm, 1.5μm and 230 nm and different phosphor concentrations (1.6%, 5.3% and 21.3 %) and thicknesses (from 5.2 to 49μm). Films were irradiated in narrow x-ray spectra (N60, N80, N-150 and N-300) and the signal intensity relative to the nominal dose-to-water value was normalized to Co-60. Finally, we experimentally tested the response of several films in Varian 6MV TrueBeam STx linear accelerator using the following settings: 10 × 10 cm2field, 0deggantry angle, 90 cm SSD, 10 cm depth. The x-ray irradiation experiment reported a reduced energy response for the smallest grain size with an inverse correlation between response and grain size. The N-60 irradiation showed a 43% reduction in the energy over-response when going from 3μm to 230 nm grain size for the 5% phosphor concentration. Energy response calculation using a homogeneous dispersion of the phosphor underestimated the experimental response and was not able to obtain the experimental correlation between grain size and energy response. Isolated grain size modeling combined with MC dose simulations allowed to establish a good agreement with experimental data, and enabled steering the production of optimized OSL-films. The clinical 6 MV beam test confirmed a reduction in energy dependence, which is visible in small-grain films where a decrease in out-of-field over-response was observed.
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Affiliation(s)
| | - Marco Caprioli
- Department of Oncology, KU Leuven, Herestraat 49, Leuven, Belgium
| | | | - Laurence Delombaerde
- Department of Oncology, KU Leuven, Herestraat 49, Leuven, Belgium
- Department of Radiation Oncology, University Hospitals Leuven, Herestraat 49, Leuven, B-3000, Belgium
| | - Katleen Himschoot
- Corporate Innovation Office, Agfa N.V., Septestraat 27, Mortsel, B-2640, Belgium
| | - Dirk Vandenbroucke
- Corporate Innovation Office, Agfa N.V., Septestraat 27, Mortsel, B-2640, Belgium
| | - Paul Leblans
- Corporate Innovation Office, Agfa N.V., Septestraat 27, Mortsel, B-2640, Belgium
| | - Wouter Crijns
- Department of Radiation Oncology, University Hospitals Leuven, Herestraat 49, Leuven, B-3000, Belgium
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Vanreusel V, Gasparini A, Galante F, Mariani G, Pacitti M, Colijn A, Reniers B, Yalvac B, Vandenbroucke D, Peeters M, Leblans P, Felici G, Verellen D, de Freitas Nascimento L. Optically stimulated luminescence system as an alternative for radiochromic film for 2D reference dosimetry in UHDR electron beams. Phys Med 2023; 114:103147. [PMID: 37804712 DOI: 10.1016/j.ejmp.2023.103147] [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: 02/28/2023] [Revised: 08/18/2023] [Accepted: 09/21/2023] [Indexed: 10/09/2023] Open
Abstract
Radiotherapy is part of the treatment of over 50% of cancer patients. Its efficacy is limited by the radiotoxicity to the healthy tissue. FLASH-RT is based on the biological effect that ultra-high dose rates (UHDR) and very short treatment times strongly reduce normal tissue toxicity, while preserving the anti-tumoral effect. Despite many positive preclinical results, the translation of FLASH-RT to the clinic is hampered by the lack of accurate dosimetry for UHDR beams. To date radiochromic film is commonly used for dose assessment but has the drawback of lengthy and cumbersome read out procedures. In this work, we investigate the equivalence of a 2D OSL system to radiochromic film dosimetry in terms of dose rate independency. The comparison of both systems was done using the ElectronFlash linac. We investigated the dose rate dependence by variation of the (1) modality, (2) pulse repetition frequency, (3) pulse length and (4) source to surface distance. Additionally, we compared the 2D characteristics by field size measurements. The OSL calibration showed transferable between conventional and UHDR modality. Both systems are equally independent of average dose rate, pulse length and instantaneous dose rate. The OSL system showed equivalent in field size determination within 3 sigma. We show the promising nature of the 2D OSL system to serve as alternative for radiochromic film in UHDR electron beams. However, more in depth characterization is needed to assess its full potential.
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Affiliation(s)
- Verdi Vanreusel
- Research in Dosimetric Applications, SCK CEN, Boeretang 200, 2400 Mol, Belgium; CORE, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium; Iridium Netwerk, Oosterveldlaan 22, 2610 Wilrijk, Belgium.
| | - Alessia Gasparini
- CORE, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium; Iridium Netwerk, Oosterveldlaan 22, 2610 Wilrijk, Belgium
| | - Federica Galante
- Sordina IORT Technologies S.p.A., Via dell'Industria, 1/A, 04011 Aprilia, Latina, Italy
| | - Giulia Mariani
- Sordina IORT Technologies S.p.A., Via dell'Industria, 1/A, 04011 Aprilia, Latina, Italy
| | - Matteo Pacitti
- Sordina IORT Technologies S.p.A., Via dell'Industria, 1/A, 04011 Aprilia, Latina, Italy
| | - Arnaud Colijn
- CORE, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - Brigitte Reniers
- NuTeC, CMK, Hasselt University, Wetenschapspark 27, 3590 Diepenbeek, Belgium
| | - Burak Yalvac
- NuTeC, CMK, Hasselt University, Wetenschapspark 27, 3590 Diepenbeek, Belgium
| | | | | | - Paul Leblans
- Agfa N.V., Septestraat 27, 2640 Mortsel, Belgium
| | - Giuseppe Felici
- Sordina IORT Technologies S.p.A., Via dell'Industria, 1/A, 04011 Aprilia, Latina, Italy
| | - Dirk Verellen
- CORE, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium; Iridium Netwerk, Oosterveldlaan 22, 2610 Wilrijk, Belgium
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Gasparian PBG, Malthez ALMC, Campos LL. Using the optically stimulated luminescence technique for one- and two-dimensional dose mapping: a brief review. Phys Med Biol 2022; 67. [DOI: 10.1088/1361-6560/ac9030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Accepted: 09/07/2022] [Indexed: 11/12/2022]
Abstract
Abstract
In respect of radiation dosimetry, several applications require dose distribution verification rather than absolute dosimetry. Most protocols use radiological and radiochromic films and ionization chambers or diode arrays for dose mapping. The films are disposable which causes the precision of the results dependent on film production variability. The measurements with arrays of ionization chambers or diodes mainly lack spatial resolution. This review aims to provide an overview of the use of optically stimulated luminescence detectors (OSLDs) for one-dimensional (1D) and two-dimensional (2D) dose mapping in different applications. It reviews the ideas, OSL materials, and applications related to the assessment of dose distribution using OSLDs in the form of film or ceramic plate (BeO). Additionally, it reviews research published in the international scientific literature from 1998 to 2021. As an outcome, a table containing the main characteristics of each relevant paper is shown. The results section was divided by the type of OSL material, and we briefly described the principal findings and the significant developments of each mentioned study such as film production and OSL reader assembly. The purpose of this study was to present an overview of the main findings of several research groups on the use of OSLD in the form of film or plate for 1D and 2D dose mapping. Finally, the potential future development of dose mapping using OSLD films was outlined.
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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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Nascimento L, Crijns W, Goveia G, Mirotta Z, Souza L, Vanhavere F, Saldarriaga Vargas C, De Saint-Hubert M. 2D reader for dose mapping in radiotherapy using radiophotoluminescent films. RADIAT MEAS 2019. [DOI: 10.1016/j.radmeas.2019.106202] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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