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Kopačin V, Brkić H, Ivković A, Kasabašić M, Knežević Ž, Majer M, Nodilo M, Turk T, Faj D. Development and validation of the low-cost pregnant female physical phantom for fetal dosimetry in MV photon radiotherapy. J Appl Clin Med Phys 2024; 25:e14240. [PMID: 38150580 PMCID: PMC10860449 DOI: 10.1002/acm2.14240] [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: 09/14/2023] [Revised: 10/27/2023] [Accepted: 11/27/2023] [Indexed: 12/29/2023] Open
Abstract
BACKGROUND Monte Carlo (MC) simulations or measurements in anthropomorphic phantoms are recommended for estimating fetal dose in pregnant patients in radiotherapy. Among the many existing phantoms, there is no commercially available physical phantom representing the entire pregnant woman. PURPOSE In this study, the development of a low-cost, physical pregnant female phantom was demonstrated using commercially available materials. This phantom is based on the previously published computational phantom. METHODS Three tissue substitution materials (soft tissue, lung and bone tissue substitution) were developed. To verify Tena's substitution tissue materials, their radiation properties were assessed and compared to ICRP and ICRU materials using MC simulations in MV radiotherapy beams. Validation of the physical phantom was performed by comparing fetal doses obtained by measurements in the phantom with fetal doses obtained by MC simulations in computational phantom, during an MV photon breast radiotherapy treatment. RESULTS Materials used for building Tena phantom are matched to ICRU materials using physical density, radiation absorption properties and effective atomic number. MC simulations showed that percentage depth doses of Tena and ICRU material comply within 5% for soft and lung tissue, up to 25 cm depth. In the bone tissue, the discrepancy is higher, but again within 5% up to the depth of 5 cm. When the phantom was used for fetal dose measurements in MV photon breast radiotherapy, measured fetal doses complied with fetal doses calculated using MC simulation within 15%. CONCLUSIONS Physical anthropomorphic phantom of pregnant patient can be manufactured using commercial materials and with low expenses. The files needed for 3D printing are now freely available. This enables further studies and comparison of numerical and physical experiments in diagnostic radiology or radiotherapy.
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Affiliation(s)
- Vjekoslav Kopačin
- Faculty of MedicineDepartment of RadiologyJ. J. Strossmayer University Osijek, University Hospital Center OsijekDepartment of Diagnostic and Interventional RadiologyOsijekCroatia
| | - Hrvoje Brkić
- Faculty of MedicineDepartment of Biophysics and Medical PhysicsJ. J. Strossmayer University OsijekOsijekCroatia
- Faculty of Dental Medicine and HealthDepartment of BiophysicsBiology and ChemistryJ. J. Strossmayer University OsijekOsijekCroatia
| | - Ana Ivković
- Faculty of MedicineDepartment of Biophysics and Medical PhysicsJ. J. Strossmayer University Osijek, University Hospital Center OsijekDepartment of Medical PhysicsOsijekCroatia
| | - Mladen Kasabašić
- Faculty of MedicineDepartment of Biophysics and Medical PhysicsJ. J. Strossmayer University Osijek, University Hospital Center OsijekDepartment of Medical PhysicsOsijekCroatia
| | - Željka Knežević
- Division of Materials ChemistryRuđer Bošković InstituteZagrebCroatia
| | - Marija Majer
- Division of Materials ChemistryRuđer Bošković InstituteZagrebCroatia
| | - Marijana Nodilo
- Division of Materials ChemistryRuđer Bošković InstituteZagrebCroatia
| | - Tajana Turk
- Faculty of MedicineDepartment of RadiologyJ. J. Strossmayer University Osijek, University Hospital Center OsijekDepartment of Diagnostic and Interventional RadiologyOsijekCroatia
| | - Dario Faj
- Faculty of MedicineDepartment of Biophysics and Medical PhysicsJ. J. Strossmayer University OsijekOsijekCroatia
- Faculty of Dental Medicine and HealthDepartment of BiophysicsBiology and ChemistryJ. J. Strossmayer University OsijekOsijekCroatia
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Kalidindi Y, Ganapathy AK, Nayak Y, Elumalai A, Chen DZ, Bishop G, Sanchez A, Albers B, Shetty AS, Ballard DH. Computed Tomography Attenuation of Three-Dimensional (3D) Printing Materials-Depository to Aid in Constructing 3D-Printed Phantoms. MICROMACHINES 2023; 14:1928. [PMID: 37893365 PMCID: PMC10609050 DOI: 10.3390/mi14101928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 10/06/2023] [Accepted: 10/11/2023] [Indexed: 10/29/2023]
Abstract
Three-dimensionally printed phantoms are increasingly used in medical imaging and research due to their cost-effectiveness and customizability, offering valuable alternatives to commercial phantoms. The purpose of this study was to assess the computed tomography (CT) attenuation characteristics of 27 resin materials from Formlabs, a 3D printing equipment and materials manufacturer. Cube phantoms (both solid and hollow constructions) produced with each resin were subjected to CT scanning under varying tube current-time products with attenuation measurements recorded in Hounsfield units (HU). The resins exhibited a wide range of attenuation values (-3.33 to 2666.27 HU), closely mimicking a range of human tissues, from fluids to dense bone structures. The resins also demonstrated consistent attenuation regardless of changes in the tube current. The CT attenuation analysis of FormLabs resins produced an archive of radiological imaging characteristics of photopolymers that can be utilized to construct more accurate tissue mimicking medical phantoms and improve the evaluation of imaging device performance.
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Affiliation(s)
- Yuktesh Kalidindi
- School of Medicine, Saint Louis University, St. Louis, MO 63104, USA;
| | - Aravinda Krishna Ganapathy
- School of Medicine, Washington University in St. Louis, St. Louis, MO 63110, USA; (A.K.G.); (Y.N.); (D.Z.C.)
| | - Yash Nayak
- School of Medicine, Washington University in St. Louis, St. Louis, MO 63110, USA; (A.K.G.); (Y.N.); (D.Z.C.)
| | - Anusha Elumalai
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA; (A.E.); (G.B.); (A.S.); (A.S.S.)
| | - David Z. Chen
- School of Medicine, Washington University in St. Louis, St. Louis, MO 63110, USA; (A.K.G.); (Y.N.); (D.Z.C.)
| | - Grace Bishop
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA; (A.E.); (G.B.); (A.S.); (A.S.S.)
| | - Adrian Sanchez
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA; (A.E.); (G.B.); (A.S.); (A.S.S.)
| | - Brian Albers
- St. Louis Children’s Hospital Medical 3D Printing Center, BJC Healthcare, St. Louis, MO 63110, USA;
| | - Anup S. Shetty
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA; (A.E.); (G.B.); (A.S.); (A.S.S.)
| | - David H. Ballard
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA; (A.E.); (G.B.); (A.S.); (A.S.S.)
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Kunert P, Schlattl H, Trinkl S, Giussani A, Klein L, Janich M, Reichert D, Brix G. Reproduction of a conventional anthropomorphic female chest phantom by 3D-printing: Comparison of image contrasts and absorbed doses in CT. Med Phys 2023; 50:4734-4743. [PMID: 37415411 DOI: 10.1002/mp.16587] [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: 03/23/2023] [Revised: 05/10/2023] [Accepted: 06/11/2023] [Indexed: 07/08/2023] Open
Abstract
BACKGROUND The production of individualized anthropomorphic phantoms via three-dimensional (3D) printing methods offers promising possibilities to assess and optimize radiation exposures for specifically relevant patient groups (i.e., overweighed or pregnant persons) that are not adequately represented by standardized anthropomorphic phantoms. However, the equivalence of printed phantoms must be demonstrated exemplarily with respect to the resulting image contrasts and dose distributions. PURPOSE To reproduce a conventionally produced anthropomorphic phantom of a female chest and breasts and to evaluate their equivalence with respect to image contrasts and absorbed doses at the example of a computed tomography (CT) examination of the chest. METHODS In a first step, the effect of different print settings on the CT values of printed samples was systematically investigated. Subsequently, a transversal slice and breast add-ons of a conventionally produced female body phantom were reproduced using a multi-material extrusion-based printer, considering six different types of tissues (muscle, lung, adipose, and glandular breast tissue, as well as bone and cartilage). CT images of the printed and conventionally produced phantom parts were evaluated with respect to their geometric correspondence, image contrasts, and absorbed doses measured using thermoluminescent dosimeters. RESULTS CT values of printed objects are highly sensitive to the selected print settings. The soft tissues of the conventionally produced phantom could be reproduced with a good agreement. Minor differences in CT values were observed for bone and lung tissue, whereas absorbed doses to the relevant tissues were identical within the measurement uncertainties. CONCLUSION 3D-printed phantoms are with exception of minor contrast differences equivalent to their conventionally manufactured counterparts. When comparing the two production techniques, it is important to note that conventionally manufactured phantoms should not be considered as absolute benchmarks, as they also only approximate the human body in terms of its absorption, and attenuation of x-rays as well as its geometry.
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Affiliation(s)
- Patrizia Kunert
- Department of Medical and Occupational Radiation Protection, Federal Office for Radiation Protection, Oberschleißheim, Germany
| | - Helmut Schlattl
- Department of Medical and Occupational Radiation Protection, Federal Office for Radiation Protection, Oberschleißheim, Germany
| | - Sebastian Trinkl
- Department of Medical and Occupational Radiation Protection, Federal Office for Radiation Protection, Oberschleißheim, Germany
| | - Augusto Giussani
- Department of Medical and Occupational Radiation Protection, Federal Office for Radiation Protection, Oberschleißheim, Germany
| | - Lea Klein
- Department of Radiation Oncology, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Martin Janich
- Department of Radiation Oncology, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Detlef Reichert
- Department of Physics, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Gunnar Brix
- Department of Medical and Occupational Radiation Protection, Federal Office for Radiation Protection, Oberschleißheim, Germany
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Kozee M, Weygand J, Andreozzi JM, Hunt D, Perez BA, Graham JA, Redler G. Methodology for computed tomography characterization of commercially available 3D printing materials for use in radiology/radiation oncology. J Appl Clin Med Phys 2023:e13999. [PMID: 37096305 DOI: 10.1002/acm2.13999] [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: 02/14/2023] [Revised: 03/28/2023] [Accepted: 04/01/2023] [Indexed: 04/26/2023] Open
Abstract
3D printing in medical physics provides opportunities for creating patient-specific treatment devices and in-house fabrication of imaging/dosimetry phantoms. This study characterizes several commercial fused deposition 3D printing materials with some containing nonstandard compositions. It is important to explore their similarities to human tissues and other materials encountered in patients. Uniform cylinders with infill from 50 to 100% at six evenly distributed intervals were printed using 13 different filaments. A novel approach rotating infill angle 10o between each layer avoids unwanted patterns. Five materials contained high-Z/metallic components. A clinical CT scanner with a range of tube potentials (70, 80, 100, 120, 140 kVp) was used. Density and average Hounsfield unit (HU) were measured. A commercial GAMMEX phantom mimicking various human tissues provides a comparison. Utility of the lookup tables produced is demonstrated. A methodology for calibrating print materials/parameters for a desired HU is presented. Density and HU were determined for all materials as a function of tube voltage (kVp) and infill percentage. The range of HU (-732.0-10047.4 HU) and physical densities (0.36-3.52 g/cm3 ) encompassed most tissues/materials encountered in radiology/radiotherapy applications with many overlapping those of human tissues. Printing filaments doped with high-Z materials demonstrated increased attenuation due to the photoelectric effect with decreased kVp, as found in certain endogenous materials (e.g., bone). HU was faithfully reproduced (within one standard deviation) in a 3D-printed mimic of a commercial anthropomorphic phantom section. Characterization of commercially available 3D print materials facilitates custom object fabrication for use in radiology and radiation oncology, including human tissue and common exogenous implant mimics. This allows for cost reduction and increased flexibility to fabricate novel phantoms or patient-specific devices imaging and dosimetry purposes. A formalism for calibrating to specific CT scanner, printer, and filament type/batch is presented. Utility is demonstrated by printing a commercial anthropomorphic phantom copy.
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Affiliation(s)
- Madison Kozee
- Department of Radiation Oncology, Moffitt Cancer Center, Tampa, Florida, USA
| | - Joseph Weygand
- Department of Radiation Oncology, Moffitt Cancer Center, Tampa, Florida, USA
| | | | - Dylan Hunt
- Department of Radiation Oncology, Moffitt Cancer Center, Tampa, Florida, USA
| | - Bradford A Perez
- Department of Radiation Oncology, Moffitt Cancer Center, Tampa, Florida, USA
| | - Jasmine A Graham
- Department of Radiation Oncology, Moffitt Cancer Center, Tampa, Florida, USA
| | - Gage Redler
- Department of Radiation Oncology, Moffitt Cancer Center, Tampa, Florida, USA
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Fonseca GP, Rezaeifar B, Lackner N, Haanen B, Reniers B, Verhaegen F. Dual-energy CT evaluation of 3D printed materials for radiotherapy applications. Phys Med Biol 2023; 68. [PMID: 36584391 DOI: 10.1088/1361-6560/acaf4a] [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: 07/01/2022] [Accepted: 12/30/2022] [Indexed: 12/31/2022]
Abstract
Objective. There is a continuous increase in 3D printing applications in several fields including medical imaging and radiotherapy. Although there are numerous advantages of using 3D printing for the development of customized phantoms, bolus, quality assurance devices and other clinical applications, material properties are not well known and printer settings can affect considerably the properties (e.g. density, isotropy and homogeneity) of the printed parts. This study aims to evaluate several materials and printer properties to identify a range of tissue-mimicking materials.Approach. Dual-energy CT was used to obtain the effective atomic number (Zeff) and relative electron density (RED) for thirty-one different materials including different colours of the same filament from the same manufacturer and the same type of filament from different manufacturers. In addition, a custom bone equivalent filament was developed and evaluated since a high-density filament with a composition similar to bone is not commercially available. Printing settings such as infill density, infill pattern, layer height and nozzle size were also evaluated.Main results. Large differences were observed for HU (288), RED (>10%) andZeff(>50%) for different colours of the same filament due to the colour pigment. Results show a wide HU variation (-714 to 1104), RED (0.277 to 1.480) andZeff(5.22 to 12.39) between the printed samples with some materials being comparable to commercial tissue-mimicking materials and good substitutes to a range of materials from lung to bone. Printer settings can result in directional dependency and significantly affect the homogeneity of the samples.Significance. The use of DECT to extract RED, andZeffallows for quantitative imaging and dosimetry using 3D printed materials equivalent to certified tissue-mimicking tissues.
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Affiliation(s)
- Gabriel P Fonseca
- Department of Radiation Oncology (Maastro), GROW School for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Behzad Rezaeifar
- Department of Radiation Oncology (Maastro), GROW School for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Niklas Lackner
- Department of Radiation Oncology (Maastro), GROW School for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Britt Haanen
- Department of Radiation Oncology (Maastro), GROW School for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Brigitte Reniers
- Research group NuTeC, Centre for Environmental Sciences, Hasselt University, Diepenbeek, Belgium
| | - Frank Verhaegen
- Department of Radiation Oncology (Maastro), GROW School for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands
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