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Pera O, Membrive I, Lambisto D, Quera J, Fernandez-Velilla E, Foro P, Reig A, Rodríguez N, Sanz J, Algara V, Algara M. Validation of 3D printing materials for high dose-rate brachytherapy using ionisation chamber and custom phantom. Phys Med Biol 2021; 66. [PMID: 34464938 DOI: 10.1088/1361-6560/ac226b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 08/31/2021] [Indexed: 11/12/2022]
Abstract
Methods.Measurements were taken with the Exradin A20 (Standard Imaging) ionisation chamber, and the 'homemade' MARM phantom was made with the 3D Ultimaker 2+ printer using PLA material. The material used for validation was ABS Medical from Smart Materials 3D. The irradiation was undertaken with a192Ir source by means of Varian's GammaMed Plus iX HDR equipment. EBT3 films were used to run additional tests. We compared different measurements for PLA, ABS Medical, and water. Additional validation methods, described in the bibliography, were also compared.Results.The measurements with the ionisation chamber that we obtained using the MARM phantom with PLA and ABS within the clinically relevant range (0.5-1.5 cm) differ with respect to the measures in the water reference, by 2.3% and 0.94%, respectively.Discussion.The literature describes highly heterogeneous validation methods, complicating the performance of systematic reviews and comparisons between materials. Thus, creating a phantom represents a single effort that will quickly pay off. This system enables comparisons, ensuring that geometric conditions remain stable-something that is not always possible with radiochromic films. The use of a calibrated ionisation chamber in the corresponding energy range, combined with the 'homemade' MARM phantom applied according to the proposed methodology, allows a differentiation between the attenuation of the material itself and the drop in the dose due to distance.Conclusion.The validation method for 3D printing materials, using an ionisation chamber and the MARM PLA phantom, represents an accessible, standardisable solution for manufacturing brachytherapy applicators.
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Affiliation(s)
- Oscar Pera
- Radiation Oncology Department, Hospital del Mar, Parc de Salut Mar, Passeig Marítim 25 E-08003 Barcelona, Spain.,Institut Hospital del Mar d'Investigacions Mèdiques. Barcelona, Spain.,Pompeu Fabra University. Barcelona, Spain
| | - Ismael Membrive
- Radiation Oncology Department, Hospital del Mar, Parc de Salut Mar, Passeig Marítim 25 E-08003 Barcelona, Spain.,Institut Hospital del Mar d'Investigacions Mèdiques. Barcelona, Spain
| | - Daniel Lambisto
- Medical Physics and Radiation Protection, Institut Català d'Oncologia Girona, Spain Hospital Josep Trueta. Sant Ponç, Avinguda de França 0, E-17007 Girona, Spain
| | - Jaume Quera
- Radiation Oncology Department, Hospital del Mar, Parc de Salut Mar, Passeig Marítim 25 E-08003 Barcelona, Spain.,Institut Hospital del Mar d'Investigacions Mèdiques. Barcelona, Spain.,Pompeu Fabra University. Barcelona, Spain
| | - Enric Fernandez-Velilla
- Radiation Oncology Department, Hospital del Mar, Parc de Salut Mar, Passeig Marítim 25 E-08003 Barcelona, Spain.,Institut Hospital del Mar d'Investigacions Mèdiques. Barcelona, Spain
| | - Palmira Foro
- Radiation Oncology Department, Hospital del Mar, Parc de Salut Mar, Passeig Marítim 25 E-08003 Barcelona, Spain.,Institut Hospital del Mar d'Investigacions Mèdiques. Barcelona, Spain.,Pompeu Fabra University. Barcelona, Spain
| | - Ana Reig
- Radiation Oncology Department, Hospital del Mar, Parc de Salut Mar, Passeig Marítim 25 E-08003 Barcelona, Spain.,Institut Hospital del Mar d'Investigacions Mèdiques. Barcelona, Spain
| | - Nuria Rodríguez
- Radiation Oncology Department, Hospital del Mar, Parc de Salut Mar, Passeig Marítim 25 E-08003 Barcelona, Spain.,Institut Hospital del Mar d'Investigacions Mèdiques. Barcelona, Spain.,Pompeu Fabra University. Barcelona, Spain
| | - Javier Sanz
- Radiation Oncology Department, Hospital del Mar, Parc de Salut Mar, Passeig Marítim 25 E-08003 Barcelona, Spain.,Institut Hospital del Mar d'Investigacions Mèdiques. Barcelona, Spain.,Pompeu Fabra University. Barcelona, Spain
| | | | - Manuel Algara
- Radiation Oncology Department, Hospital del Mar, Parc de Salut Mar, Passeig Marítim 25 E-08003 Barcelona, Spain.,Institut Hospital del Mar d'Investigacions Mèdiques. Barcelona, Spain.,Autonomous University of Barcelona, Spain
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Soliman AS, Burns L, Owrangi A, Lee Y, Song WY, Stanisz G, Chugh BP. A realistic phantom for validating MRI-based synthetic CT images of the human skull. Med Phys 2017. [PMID: 28644905 DOI: 10.1002/mp.12428] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
PURPOSE To introduce a new realistic human skull phantom for the validation of synthetic CT images of cortical bone from ultra-short echo-time (UTE) sequences. METHODS A human skull of an adult female was utilized as a realistic representation of skull cortical bone. The skull was stabilized in a special acrylic container and was filled with contrast agents that have T1 and T2 relaxation times similar to human brain. The phantom was MR scanned at 3T with UTE and T2 -weighted sequences, followed by CT. A clustering approach was developed to extract the cortical bone signal from MR images. T2∗ maps of the skull were calculated. Synthetic CT images of the bone were compared to cortical bone signal extracted from CT images and confounding factors, such as registration errors, were analyzed. RESULTS Dice similarity coefficient (DSC) of UTE-detected cortical bone was 0.84 and gradually decreased with decreasing number of spokes. DSC did not significantly depend on echo-time. Registration errors were found to be significant confounding factors, with 25% decrease in DSC for consistent 2 mm error at each axis. CONCLUSION This work introduced a new realistic human skull phantom, specifically for the evaluation and analysis of synthetic CT images of cortical bone.
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Affiliation(s)
- Abraam S Soliman
- Medical Physics, Sunnybrook Health Sciences Centre, Toronto, ON, M4N 3M5, Canada.,Physical Sciences, Sunnybrook Research Institute, Toronto, ON, M4N 3M5, Canada
| | - Levi Burns
- Medical Physics, Sunnybrook Health Sciences Centre, Toronto, ON, M4N 3M5, Canada.,Physics and Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z1, Canada
| | - Amir Owrangi
- Medical Physics, Sunnybrook Health Sciences Centre, Toronto, ON, M4N 3M5, Canada.,Radiation Oncology, University of Toronto, Toronto, ON, M5S 3E2, Canada
| | - Young Lee
- Medical Physics, Sunnybrook Health Sciences Centre, Toronto, ON, M4N 3M5, Canada.,Radiation Oncology, University of Toronto, Toronto, ON, M5S 3E2, Canada
| | - William Y Song
- Medical Physics, Sunnybrook Health Sciences Centre, Toronto, ON, M4N 3M5, Canada.,Physical Sciences, Sunnybrook Research Institute, Toronto, ON, M4N 3M5, Canada.,Radiation Oncology, University of Toronto, Toronto, ON, M5S 3E2, Canada
| | - Greg Stanisz
- Medical Physics, Sunnybrook Health Sciences Centre, Toronto, ON, M4N 3M5, Canada.,Physical Sciences, Sunnybrook Research Institute, Toronto, ON, M4N 3M5, Canada.,Medical Biophysics, University of Toronto, Toronto, ON, M4N 3M5, Canada
| | - Brige P Chugh
- Medical Physics, Sunnybrook Health Sciences Centre, Toronto, ON, M4N 3M5, Canada.,Radiation Oncology, University of Toronto, Toronto, ON, M5S 3E2, Canada
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