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A K SN, Saxena K, Puzhakkal N, Mathew J, K DL. Development and validation of 3D printed anthropomorphic head phantom with eccentric holes for medical LINAC quality assurance testing in stereotactic radiosurgery. Med Eng Phys 2024; 130:104217. [PMID: 39160023 DOI: 10.1016/j.medengphy.2024.104217] [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: 06/30/2023] [Revised: 04/05/2024] [Accepted: 07/31/2024] [Indexed: 08/21/2024]
Abstract
Stereotactic Radiosurgery (SRS) for brain tumors using Medical Linear Accelerator (LINAC) demands high precision and accuracy. A specific Quality Assurance (QA) is essential for every patient undergoing SRS to protect nearby non-cancerous cells by ensuring that the X-ray beams are targeted according to tumor position. In this work, a water-filled generic anthropomorphic head phantom consisting of two removable parts with eccentric holes was developed using Additive Manufacturing (AM) process for performing QA in SRS. In the patient specific QA, the planned radiation dose using Treatment Planning System (TPS) was compared with the dose measured in the phantom. Also, the energy consistency of radiation beams was tested at 200 MU for different energy beams at the central and eccentric holes of the phantom using an ionization chamber. Experimentally examined results show that planned doses in TPS are reaching the target within a 5% deviation. The ratio of the dose delivered in the eccentric hole to the dose delivered to the central hole shows variations of less than 2% for the energy consistency test. The designed, low-cost water-filled anthropomorphic phantom is observed to improve positioning verification and accurate dosimetry of patient-specific QA in SRS treatment.
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Affiliation(s)
- Shahi Nabhan A K
- Department of Mechanical Engineering, National Institute of Technology, Calicut, India
| | - Kritik Saxena
- Department of Mechanical Engineering, National Institute of Technology, Calicut, India
| | - Niyas Puzhakkal
- Department of Radiation Oncology, MVR Cancer Center and Research Institute, Calicut, India
| | - Jose Mathew
- Department of Mechanical Engineering, National Institute of Technology, Calicut, India
| | - Deepak Lawrence K
- Department of Mechanical Engineering, National Institute of Technology, Calicut, India.
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Mossahebi S, Byrne K, Jiang K, Gerry A, Deng W, Repetto C, Jackson IL, Sawant A, Poirier Y. A high-throughput focused collimator for OAR-sparing preclinical proton FLASH studies: commissioning and validation. Phys Med Biol 2024; 69:14NT01. [PMID: 38876112 DOI: 10.1088/1361-6560/ad589f] [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: 03/23/2024] [Accepted: 06/14/2024] [Indexed: 06/16/2024]
Abstract
Objective. To fabricate and validate a novel focused collimator designed to spare normal tissue in a murine hemithoracic irradiation model using 250 MeV protons delivered at ultra-high dose rates (UHDRs) for preclinical FLASH radiation therapy (FLASH-RT) studies.Approach. A brass collimator was developed to shape 250 MeV UHDR protons from our Varian ProBeam. Six 13 mm apertures, of equivalent size to kV x-ray fields historically used to perform hemithorax irradiations, were precisely machined to match beam divergence, allowing concurrent hemithoracic irradiation of six mice while sparing the contralateral lung and abdominal organs. The collimated field profiles were characterized by film dosimetry, and a radiation survey of neutron activation was performed to ensure the safety of staff positioning animals.Main results. The brass collimator produced 1.2 mm penumbrae radiation fields comparable to kV x-rays used in preclinical studies. The penumbrae in the six apertures are similar, with full-width half-maxima of 13.3 mm and 13.5 mm for the central and peripheral apertures, respectively. The collimator delivered a similar dose at an average rate of 52 Gy s-1for all apertures. While neutron activation produces a high (0.2 mSv h-1) initial ambient equivalent dose rate, a parallel work-flow in which imaging and setup are performed without the collimator ensures safety to staff.Significance. Scanned protons have the greatest potential for future translation of FLASH-RT in clinical treatments due to their ability to treat deep-seated tumors with high conformality. However, the Gaussian distribution of dose in proton spots produces wider lateral penumbrae compared to other modalities. This presents a challenge in small animal pre-clinical studies, where millimeter-scale penumbrae are required to precisely target the intended volume. Offering high-throughput irradiation of mice with sharp penumbrae, our novel collimator-based platform serves as an important benchmark for enabling large-scale, cost-effective radiobiological studies of the FLASH effect in murine models.
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Affiliation(s)
- Sina Mossahebi
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Kevin Byrne
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Kai Jiang
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Andrew Gerry
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Wei Deng
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Carlo Repetto
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Isabel L Jackson
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD, United States of America
- True North Biopharm, LLC, Rockville, MD, United States of America
| | - Amit Sawant
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Yannick Poirier
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD, United States of America
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Iweka E, Ezenwuba BN, Snaith B. Research designs of publications in radiography professional journals - A modified bibliometric analysis. Radiography (Lond) 2024; 30:1210-1218. [PMID: 38905765 DOI: 10.1016/j.radi.2024.06.005] [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: 04/04/2024] [Revised: 05/28/2024] [Accepted: 06/09/2024] [Indexed: 06/23/2024]
Abstract
INTRODUCTION Evidence based practice relies on availability of research evidence mostly through peer-reviewed journal publications. No consensus currently exists on the best hierarchy of research evidence, often categorised by the adopted research designs. Analysing the prevalent research designs in radiography professional journals is one vital step in considering an evidence hierarchy specific to the radiography profession and this forms the aim of this study. METHODS Bibliometric data of publications in three Radiography professional journals within a 10-year period were extracted. The Digital Object Identifier were used to locate papers on publishers' websites and obtain relevant data for analysis. Descriptive analysis using frequencies and percentages were used to represent data while Chi-square was used to analyse relationship between categorical variables. RESULTS 1830 articles met the pre-set inclusion criteria. Quantitative descriptive studies were the most published design (26.6%) followed by non-RCT experimental studies (18.7%), while Randomised Controlled Trials (RCT) were the least published (1.0%). Systematic reviews (42.9%) showed the highest average percentage increase within the 10-year period, however RCTs showed no net increase. Single-centre studies predominated among experimental studies (RCT = 88.9%; Non-RCT = 95%). Author collaboration across all study designs was notable, with RCTs showing the most (100%). Quantitative and qualitative studies comparatively had similar number of citations when publication numbers were matched. Quantitative descriptive studies had the highest cumulative citations while RCTs had the least. CONCLUSION There is a case to advocate for more study designs towards the peak of evidence hierarchies such as systematic reviews and RCT. Radiography research should be primarily designed to answer pertinent questions and improve the validity of the profession's evidence base. IMPLICATION FOR PRACTICE The evidence presented can encourage the adoption of the research designs that enhances radiography profession's evidence base.
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Affiliation(s)
- E Iweka
- Research/Clinical Trials, Radiology, University Hospitals of Derby and Burton NHS Foundation Trust, UK.
| | - B N Ezenwuba
- Sheffield Teaching Hospitals NHS Foundation Trust.
| | - B Snaith
- University of Bradford, Bradford, UK; Mid Yorkshire Hospitals Teaching NHS Trust, Wakefield, UK.
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Basaula D, Hay B, Wright M, Hall L, Easdon A, McWiggan P, Yeo A, Ungureanu E, Kron T. Additive manufacturing of patient specific bolus for radiotherapy: large scale production and quality assurance. Phys Eng Sci Med 2024; 47:551-561. [PMID: 38285272 PMCID: PMC11166743 DOI: 10.1007/s13246-024-01385-1] [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: 05/27/2023] [Accepted: 01/07/2024] [Indexed: 01/30/2024]
Abstract
Bolus is commonly used to improve dose distributions in radiotherapy in particular if dose to skin must be optimised such as in breast or head and neck cancer. We are documenting four years of experience with 3D printed bolus at a large cancer centre. In addition to this we review the quality assurance (QA) program developed to support it. More than 2000 boluses were produced between Nov 2018 and Feb 2023 using fused deposition modelling (FDM) printing with polylactic acid (PLA) on up to five Raise 3D printers. Bolus is designed in the radiotherapy treatment planning system (Varian Eclipse), exported to an STL file followed by pre-processing. After checking each bolus with CT scanning initially we now produce standard quality control (QC) wedges every month and whenever a major change in printing processes occurs. A database records every bolus printed and manufacturing details. It takes about 3 days from designing the bolus in the planning system to delivering it to treatment. A 'premium' PLA material (Spidermaker) was found to be best in terms of homogeneity and CT number consistency (80 HU +/- 8HU). Most boluses were produced for photon beams (93.6%) with the rest used for electrons. We process about 120 kg of PLA per year with a typical bolus weighing less than 500 g and the majority of boluses 5 mm thick. Print times are proportional to bolus weight with about 24 h required for 500 g material deposited. 3D printing using FDM produces smooth and reproducible boluses. Quality control is essential but can be streamlined.
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Affiliation(s)
- Deepak Basaula
- Peter MacCallum Cancer Centre, Department of Physical Sciences, 305 Grattan Street, Melbourne, VIC, 3000, Australia
| | - Barry Hay
- Peter MacCallum Cancer Centre, Department of Radiation Engineering, Melbourne, Australia
| | - Mark Wright
- Peter MacCallum Cancer Centre, Department of Radiation Engineering, Melbourne, Australia
| | - Lisa Hall
- Peter MacCallum Cancer Centre, Department of Radiation Therapy, Melbourne, Australia
| | - Alan Easdon
- Peter MacCallum Cancer Centre, Department of Radiation Engineering, Melbourne, Australia
| | - Peter McWiggan
- Peter MacCallum Cancer Centre, Department of Radiation Engineering, Melbourne, Australia
| | - Adam Yeo
- Peter MacCallum Cancer Centre, Department of Physical Sciences, 305 Grattan Street, Melbourne, VIC, 3000, Australia
- School of Applied Sciences, RMIT University, Melbourne, Australia
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Australia
| | - Elena Ungureanu
- Peter MacCallum Cancer Centre, Department of Physical Sciences, 305 Grattan Street, Melbourne, VIC, 3000, Australia
| | - Tomas Kron
- Peter MacCallum Cancer Centre, Department of Physical Sciences, 305 Grattan Street, Melbourne, VIC, 3000, Australia.
- School of Applied Sciences, RMIT University, Melbourne, Australia.
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia.
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Australia.
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Mukwada G, Hirst A, Rowshanfarzad P, Ebert MA. Development of a 3D printed phantom for commissioning and quality assurance of multiple brain targets stereotactic radiosurgery. Phys Eng Sci Med 2024; 47:455-463. [PMID: 38285271 PMCID: PMC11166808 DOI: 10.1007/s13246-023-01374-w] [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: 07/13/2023] [Accepted: 12/18/2023] [Indexed: 01/30/2024]
Abstract
Single plan techniques for multiple brain targets (MBT) stereotactic radiosurgery (SRS) are now routine. Patient specific quality assurance (QA) for MBT poses challenges due to the limited capabilities of existing QA tools which necessitates several plan redeliveries. This study sought to develop an SRS QA phantom that enables flexible MBT patient specific QA in a single delivery, along with complex SRS commissioning. PLA marble and PLA StoneFil materials were selected based on the literature and previous research conducted in our department. The HU numbers were investigated to determine the appropriate percentage infill for skull and soft-tissue equivalence. A Prusa MK3S printer in conjunction with the above-mentioned filaments were used to print the SRS QA phantom. Quality control (QC) was performed on the printed skull, film inserts and plugs for point dose measurements. EBT3 film and point dose measurements were performed using a CC04 ionisation chamber. QC demonstrated that the SRS QA phantom transverse, coronal and sagittal film planes were orthogonal within 0.5°. HU numbers for the skull, film inserts and plugs were 858 ± 20 and 35 ± 12 respectively. Point and EBT3 film dose measurements were within 2.5% and 3%/2 mm 95% gamma pass rate, respectively except one Gross Tumour Volume (GTV) that had a slightly lower gamma pass rate. Dose distributions to five GTVs were measured with EBT3 film in a single plan delivery on CyberKnife. In conclusion, an SRS QA phantom was designed, and 3D printed and its use for performing complex MBT patient specific QA in a single delivery was demonstrated.
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Affiliation(s)
- Godfrey Mukwada
- Department of Radiation Oncology, Sir Charles Gairdner Hospital, Hospital Ave, Nedlands, WA, Australia.
- School of Physics, Mathematics and Computing, University of Western Australia, Crawley, WA, Australia.
| | - Andrew Hirst
- Department of Radiation Oncology, Sir Charles Gairdner Hospital, Hospital Ave, Nedlands, WA, Australia
| | - Pejman Rowshanfarzad
- School of Physics, Mathematics and Computing, University of Western Australia, Crawley, WA, Australia
| | - Martin A Ebert
- Department of Radiation Oncology, Sir Charles Gairdner Hospital, Hospital Ave, Nedlands, WA, Australia
- School of Physics, Mathematics and Computing, University of Western Australia, Crawley, WA, Australia
- Medical School, Australian Centre for Quantitative Imaging, University of Western Australia, Crawley, WA, Australia
- School of Medicine and Population Health, University of Wisconsin, Madison, WI, USA
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Bustillo JPO, Paino J, Barnes M, Cameron M, Rosenfeld AB, Lerch MLF. Characterization of selected additive manufacturing materials for synchrotron monochromatic imaging and broad-beam radiotherapy at the Australian synchrotron-imaging and medical beamline. Phys Med Biol 2024; 69:115055. [PMID: 38718813 DOI: 10.1088/1361-6560/ad48f7] [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: 01/19/2024] [Accepted: 05/08/2024] [Indexed: 05/31/2024]
Abstract
Objective.This study aims to characterize radiological properties of selected additive manufacturing (AM) materials utilizing both material extrusion and vat photopolymerization technologies. Monochromatic synchrotron x-ray images and synchrotron treatment beam dosimetry were acquired at the hutch 3B and 2B of the Australian Synchrotron-Imaging and Medical Beamline.Approach.Eight energies from 30 keV up to 65 keV were used to acquire the attenuation coefficients of the AM materials. Comparison of theoretical, and experimental attenuation data of AM materials and standard solid water for MV linac was performed. Broad-beam dosimetry experiment through attenuated dose measurement and a Geant4 Monte Carlo simulation were done for the studied materials to investigate its attenuation properties specific for a 4 tesla wiggler field with varying synchrotron radiation beam qualities.Main results.Polylactic acid (PLA) plus matches attenuation coefficients of both soft tissue and brain tissue, while acrylonitrile butadiene styrene, Acrylonitrile styrene acrylate, and Draft resin have close equivalence to adipose tissue. Lastly, PLA, co-polyester plus, thermoplastic polyurethane, and White resins are promising substitute materials for breast tissue. For broad-beam experiment and simulation, many of the studied materials were able to simulate RMI457 Solid Water and bolus within ±10% for the three synchrotron beam qualities. These results are useful in fabricating phantoms for synchrotron and other related medical radiation applications such as orthovoltage treatments.Significance and conclusion.These 3D printing materials were studied as potential substitutes for selected tissues such as breast tissue, adipose tissue, soft-tissue, and brain tissue useful in fabricating 3D printed phantoms for synchrotron imaging, therapy, and orthovoltage applications. Fabricating customizable heterogeneous anthropomorphic phantoms (e.g. breast, head, thorax) and pre-clinical animal phantoms (e.g. rodents, canine) for synchrotron imaging and radiotherapy using AM can be done based on the results of this study.
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Affiliation(s)
- John Paul O Bustillo
- Center for Medical Radiation Physics, University of Wollongong Australia, Wollongong, NSW 2522, Australia
- Department of Physical Sciences and Mathematics, College of Arts and Sciences, University of the Philippines Manila, Ermita, Manila City 1000, Metro Manila, The Philippines
| | - Jason Paino
- Center for Medical Radiation Physics, University of Wollongong Australia, Wollongong, NSW 2522, Australia
| | - Micah Barnes
- Center for Medical Radiation Physics, University of Wollongong Australia, Wollongong, NSW 2522, Australia
- Imaging and Medical Beamline, Australian Nuclear Science and Technology Organisation- Australian Synchrotron, Kulin Nation, Clayton, VIC 3168, Australia
| | - Matthew Cameron
- Imaging and Medical Beamline, Australian Nuclear Science and Technology Organisation- Australian Synchrotron, Kulin Nation, Clayton, VIC 3168, Australia
| | - Anatoly B Rosenfeld
- Center for Medical Radiation Physics, University of Wollongong Australia, Wollongong, NSW 2522, Australia
| | - Michael L F Lerch
- Center for Medical Radiation Physics, University of Wollongong Australia, Wollongong, NSW 2522, Australia
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Quiñones LÁ, Sánchez A, Pérez J, Seguro Á, Castro I, Castanedo M, Vicent D, Iborra MA. Thermoplastic polymers as water substitutes. Biomed Phys Eng Express 2024; 10:045009. [PMID: 38670074 DOI: 10.1088/2057-1976/ad43ee] [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: 01/10/2024] [Accepted: 04/26/2024] [Indexed: 04/28/2024]
Abstract
Background. New applications of 3D printing have recently appeared in the fields of radiotherapy and radiology, but the knowledge of many radiological characteristics of the compounds involved is still limited. Therefore, studies are needed to improve our understanding about the transport and interaction of ionizing radiation in these materials.Purpose. The purpose of this study is to perform an analysis of the most important radiation interaction parameters in thermoplastic materials used in Fused Deposition Modeling 3D printing. Additionally, we propose improvements to bring their characteristics closer to those of water and use them as water substitutes in applications such as radiodiagnosis, external radiotherapy, and brachytherapy.Methods. We have calculated different magnitudes as mass linear attenuation, mass energy absorption coefficients, as well as stopping power and electronic density of several thermoplastic materials along with various compounds that have been used as water substitutes and in a new proposed blend. To perform these computations, we have used the XCOM and ESTAR databases from NIST and the EGSnrc code for Montecarlo simulations.Results. From the representation of the calculated interaction parameters, we have been able to establish relationships between their properties and the proportion of certain chemical elements. In addition, studying these same characteristics in different commercial solutions used as substitutes for water phantoms allows us to extrapolate improvements for these polymers.Conclusion. The radiological characteristics of the analyzed thermoplastic materials can be improved by adding some chemical elements with atomic numbers higher than oxygen and by using polyethylene in new blends.
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Affiliation(s)
- Luis Ángel Quiñones
- Medical Physics Service, Hospital Universitario Puerta del Mar, Avda. Ana de Viya, No 21. 11009, Cádiz, Spain
| | - Andrea Sánchez
- Medical Physics Service, Hospital Universitario Puerta del Mar, Avda. Ana de Viya, No 21. 11009, Cádiz, Spain
| | - Joaquín Pérez
- Medical Physics Service, Hospital Universitario Puerta del Mar, Avda. Ana de Viya, No 21. 11009, Cádiz, Spain
| | - Álvaro Seguro
- Medical Physics Service, Hospital Universitario Puerta del Mar, Avda. Ana de Viya, No 21. 11009, Cádiz, Spain
| | - Ignacio Castro
- Medical Physics Service, Hospital Universitario Puerta del Mar, Avda. Ana de Viya, No 21. 11009, Cádiz, Spain
| | - Miguel Castanedo
- Medical Physics Service, Hospital Universitario Puerta del Mar, Avda. Ana de Viya, No 21. 11009, Cádiz, Spain
| | - Diana Vicent
- Medical Physics Service, Hospital Universitario Puerta del Mar, Avda. Ana de Viya, No 21. 11009, Cádiz, Spain
| | - María Amparo Iborra
- Medical Physics Service, Hospital Universitario Puerta del Mar, Avda. Ana de Viya, No 21. 11009, Cádiz, Spain
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Ahmed AMM, Buschmann M, Breyer L, Kuntner C, Homolka P. Tailoring the Mass Density of 3D Printing Materials for Accurate X-ray Imaging Simulation by Controlled Underfilling for Radiographic Phantoms. Polymers (Basel) 2024; 16:1116. [PMID: 38675035 PMCID: PMC11053449 DOI: 10.3390/polym16081116] [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: 02/28/2024] [Revised: 03/26/2024] [Accepted: 04/11/2024] [Indexed: 04/28/2024] Open
Abstract
Additive manufacturing and 3D printing allow for the design and rapid production of radiographic phantoms for X-ray imaging, including CT. These are used for numerous purposes, such as patient simulation, optimization of imaging procedures and dose levels, system evaluation and quality assurance. However, standard 3D printing polymers do not mimic X-ray attenuation properties of tissues like soft, adipose, lung or bone tissue, and standard materials like liquid water. The mass density of printing polymers-especially important in CT-is often inappropriate, i.e., mostly too high. Different methods can be applied to reduce mass density. This work examines reducing density by controlled underfilling either realized by using 3D printing materials expanded through foaming during heating in the printing process, or reducing polymer flow to introduce microscopic air-filled voids. The achievable density reduction depends on the base polymer used. When using foaming materials, density is controlled by the extrusion temperature, and ranges from 33 to 47% of the base polymer used, corresponding to a range of -650 to -394 HU in CT with 120 kV. Standard filaments (Nylon, modified PLA and modified ABS) allowed density reductions by 20 to 25%, covering HU values in CT from -260 to 77 (Nylon), -230 to -20 (ABS) and -81 to 143 (PLA). A standard chalk-filled PLA filament allowed reproduction of bone tissue in a wide range of bone mineral content resulting in CT numbers from 57 to 460 HU. Controlled underfilling allowed the production of radiographic phantom materials with continuously adjustable attenuation in a limited but appropriate range, allowing for the reproduction of X-ray attenuation properties of water, adipose, soft, lung, and bone tissue in an accurate, predictable and reproducible manner.
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Affiliation(s)
| | - Martin Buschmann
- Division of Medical Radiation Physics, Department of Radiation Oncology, Medical University of Vienna, and University Hospital Vienna, 1090 Vienna, Austria;
| | - Lara Breyer
- Department of Biomedical Imaging and Image-Guided Therapy, Medical Imaging Cluster (MIC), Medical University of Vienna, 1090 Vienna, Austria; (L.B.); (C.K.)
| | - Claudia Kuntner
- Department of Biomedical Imaging and Image-Guided Therapy, Medical Imaging Cluster (MIC), Medical University of Vienna, 1090 Vienna, Austria; (L.B.); (C.K.)
| | - Peter Homolka
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, 1090 Vienna, Austria
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Singh PK, Verma R, Tripathi D, Singh S, Bhushan M, Kumar L, Barik S, Gairola M. Evaluation of the Treatment Planning and Delivery for Hip Implant Cases on Tomotherapy. J Med Phys 2024; 49:270-278. [PMID: 39131420 PMCID: PMC11309148 DOI: 10.4103/jmp.jmp_182_23] [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: 12/26/2023] [Revised: 02/16/2024] [Accepted: 02/21/2024] [Indexed: 08/13/2024] Open
Abstract
Purpose The metal present in the implant creates artifacts during the treatment simulation, which impacts the treatment planning and delivery of the prescribed dose to the target and sparing normal tissues. This retrospective study evaluated the uncertainties in the planning and delivery of doses for prosthesis cases with dedicated phantom. Materials and Methods In this retrospective study, 11 patients with a hip prosthesis having cervix carcinoma were selected. Two treatment plans were generated on treatment planning system (TPS) for each case. Plan_No_Res was without any beam restriction, and Plan_exit_only was the plan with restricted beam entry through the metallic implant. An indigenous phantom was utilized to verify the accuracy of the treatment. In the phantom, some groves were present, which could be filled by implants that mimic the patient's geometries, like left, right and bilateral femur implants. The delivered doses were recorded using optically stimulated luminescence dosimeters (OSLDs), which were placed at different positions in the phantom. The plans were further calculated using megavoltage computed tomography (MVCT) scans acquired during treatment. Results The patient data showed no significant dose changes between the two planning methods. The treatment time increases from 412.18 ± 86.65 to 427.36 ± 104.80 with P = 0.03 for Plan_No_Res and Plan_exit_only, respectively. The difference between planned and delivered doses of various points across phantom geometries was within ± 9.5% in each case as left, right, and bilateral implant. The variations between OSLDs and MVCT calculated doses were also within ± 10.8%. Conclusion The study showed the competency of tomotherapy planning for hip prosthesis cases. The phantom measurements demonstrate the errors in dosimetry near the implant material, suggesting the need for precise methods to deal with artifact-related issues.
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Affiliation(s)
- Pawan Kumar Singh
- Department of Physics, Amity Institute of Applied Sciences, Amity University (AUUP), Noida, India
- Department of Radiation Oncology, Vardhman Mahavir Medical College and Safdarjung Hospital, Delhi, India
| | - Rohit Verma
- Department of Physics, Amity Institute of Applied Sciences, Amity University (AUUP), Noida, India
| | - Deepak Tripathi
- Department of Physics, USAR, Guru Gobind Singh Indraprastha University, East Campus, Delhi, India
| | - Sukhvir Singh
- Radiation Safety Group, Institute of Nuclear Medicine and Allied Sciences, Defence Research and Development Organisation, New Delhi, India
| | - Manindra Bhushan
- Department of Radiation Oncology and Division of Medical Physics, Rajiv Gandhi Cancer Institute and Research Centre, New Delhi, India
| | - Lalit Kumar
- Department of Radiation Oncology, Max Super Speciality Hospital, New Delhi, India
| | - Soumitra Barik
- Department of Radiation Oncology and Division of Medical Physics, Rajiv Gandhi Cancer Institute and Research Centre, New Delhi, India
| | - Munish Gairola
- Department of Radiation Oncology and Division of Medical Physics, Rajiv Gandhi Cancer Institute and Research Centre, New Delhi, India
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Sourvanos D, Sun H, Zhu TC, Dimofte A, Byrd B, Busch TM, Cengel KA, Neiva R, Fiorellini JP. Three-dimensional printing of the human lung pleural cavity model for PDT malignant mesothelioma. Photodiagnosis Photodyn Ther 2024; 46:104014. [PMID: 38346466 DOI: 10.1016/j.pdpdt.2024.104014] [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: 10/31/2023] [Revised: 02/06/2024] [Accepted: 02/09/2024] [Indexed: 03/18/2024]
Abstract
OBJECTIVE The primary aim was to investigate emerging 3D printing and optical acquisition technologies to refine and enhance photodynamic therapy (PDT) dosimetry in the management of malignant pleural mesothelioma (MPM). MATERIALS AND METHODS A rigorous digital reconstruction of the pleural lung cavity was conducted utilizing 3D printing and optical scanning methodologies. These reconstructions were systematically assessed against CT-derived data to ascertain their accuracy in representing critical anatomic features and post-resection topographical variations. RESULTS The resulting reconstructions excelled in their anatomical precision, proving instrumental translation for precise dosimetry calculations for PDT. Validation against CT data confirmed the utility of these models not only for enhancing therapeutic planning but also as critical tools for educational and calibration purposes. CONCLUSION The research outlined a successful protocol for the precise calculation of light distribution within the complex environment of the pleural cavity, marking a substantive advance in the application of PDT for MPM. This work holds significant promise for individualizing patient care, minimizing collateral radiation exposure, and improving the overall efficiency of MPM treatments.
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Affiliation(s)
- Dennis Sourvanos
- Department of Periodontics, School of Dental Medicine, University of Pennsylvania, PA, USA; Center for Innovation and Precision Dentistry (CiPD), School of Dental Medicine, School of Engineering, University of Pennsylvania, PA, USA.
| | - Hongjing Sun
- Department of Radiation Oncology, Perelman Center for Advanced Medicine, University of Pennsylvania, PA, USA
| | - Timothy C Zhu
- Department of Radiation Oncology, Perelman Center for Advanced Medicine, University of Pennsylvania, PA, USA
| | - Andreea Dimofte
- Department of Radiation Oncology, Perelman Center for Advanced Medicine, University of Pennsylvania, PA, USA
| | - Brook Byrd
- Department of Radiation Oncology, Perelman Center for Advanced Medicine, University of Pennsylvania, PA, USA
| | - Theresa M Busch
- Department of Radiation Oncology, Perelman Center for Advanced Medicine, University of Pennsylvania, PA, USA
| | - Keith A Cengel
- Department of Radiation Oncology, Perelman Center for Advanced Medicine, University of Pennsylvania, PA, USA
| | - Rodrigo Neiva
- Department of Periodontics, School of Dental Medicine, University of Pennsylvania, PA, USA
| | - Joseph P Fiorellini
- Department of Periodontics, School of Dental Medicine, University of Pennsylvania, PA, USA
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11
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Schulz JB, Dubrowski P, Gibson C, Yu AS, Skinner LB. A clinical solution for non-toxic 3D-printed photon blocks in external beam radiation therapy. J Appl Clin Med Phys 2024; 25:e14225. [PMID: 38213084 DOI: 10.1002/acm2.14225] [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: 06/08/2023] [Revised: 10/14/2023] [Accepted: 10/21/2023] [Indexed: 01/13/2024] Open
Abstract
PURPOSE A well-known limitation of multi-leaf collimators is that they cannot easily form island blocks. This can be important in mantle region therapy. Cerrobend photon blocks, currently used for supplementary shielding, are labor-intensive and error-prone. To address this, an innovative, non-toxic, automatically manufactured photon block using 3D-printing technology is proposed, offering a patient-specific and accurate alternative. METHODS AND MATERIALS The study investigates the development of patient-specific photon shielding blocks using 3D-printing for three different patient cases. A 3D-printed photon block shell filled with tungsten ball bearings (BBs) was designed to have similar dosimetric properties to Cerrobend standards. The generation of the blocks was automated using the Eclipse Scripting API and Python. Quality assurance was performed by comparing the expected and actual weight of the tungsten BBs used for shielding. Dosimetric and field geometry comparisons were conducted between 3D-printed and Cerrobend blocks, utilizing ionization chambers, imaging, and field geometry analysis. RESULTS The quality assurance assessment revealed a -1.3% average difference in the mass of tungsten ball bearings for different patients. Relative dose output measurements for three patient-specific blocks in the blocked region agreed within 2% of each other. Against the Treatment Planning System (TPS), both 3D-printed and Cerrobend blocks agreed within 2%. For each patient, 6 MV image profiles taken through the 3D-printed and Cerrobend blocks agreed within 1% outside high gradient regions. Jaccard distance analysis of the MV images against the TPS planned images, found Cerrobend blocks to have 15.7% dissimilarity to the TPS, while that of the 3D-printed blocks was 6.7%. CONCLUSIONS This study validates a novel, efficient 3D-printing method for photon block creation in clinical settings. Despite potential limitations, the benefits include reduced manual labor, automated processes, and greater precision. It holds potential for widespread adoption in radiation therapy, furthering non-toxic radiation shielding.
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Affiliation(s)
- Joseph B Schulz
- Department of Radiation Oncology, School of Medicine, Stanford University, Stanford, California, USA
| | - Piotr Dubrowski
- Department of Radiation Oncology, School of Medicine, Stanford University, Stanford, California, USA
| | - Clinton Gibson
- Department of Radiation Oncology, School of Medicine, Stanford University, Stanford, California, USA
| | - Amy S Yu
- Department of Radiation Oncology, School of Medicine, Stanford University, Stanford, California, USA
| | - Lawrie Basil Skinner
- Department of Radiation Oncology, School of Medicine, Stanford University, Stanford, California, USA
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12
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Cristant C, Kolasangiani K, Sadanand S, Bougherara H, Sussman D. Effect of Injection Parameters on the MRI and Dielectric Properties of Condensation-Cured Silicone. Polymers (Basel) 2023; 15:4670. [PMID: 38139922 PMCID: PMC10747146 DOI: 10.3390/polym15244670] [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: 10/27/2023] [Revised: 12/04/2023] [Accepted: 12/05/2023] [Indexed: 12/24/2023] Open
Abstract
Phantoms with tissue-mimicking properties play a crucial role in the calibration of medical imaging modalities, including Magnetic Resonance Imaging (MRI). Among these phantoms, silicone-based ones are widely used due to their long-term stability in MR imaging. Most of these phantoms are manufactured using traditional pour-mold techniques which often result in the production of air bubbles that can damage the phantom. This research investigates the feasibility of utilizing extrusion techniques to fabricate silicone phantoms and explores the effects of extrusion parameters including plunger speed and nozzle diameter on void content, T1 and T2 relaxation times, and dielectric properties. A custom double-syringe silicone extrusion apparatus was developed to prepare the silicone samples. The void content, relaxometry, and dielectric properties of extruded samples were measured and compared with traditional poured samples. The results show that extrusion parameters can affect the void content of the silicone samples. The presence of voids in the samples resulted in lower T1 values, indicating an inverse relationship between void content and relaxometry. This study demonstrates the potential of extrusion techniques for manufacturing silicone phantoms with reduced air bubble formation and provides valuable insights into the relationship between extrusion parameters and phantom properties.
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Affiliation(s)
- Conor Cristant
- Department of Electrical, Computer and Biomedical Engineering, Toronto Metropolitan University, Toronto, ON M5B 2K3, Canada; (C.C.); (S.S.)
- Institute for Biomedical Engineering, Science and Technology (iBEST), St. Michael’s Hospital & Toronto Metropolitan University, Toronto, ON M5B 1T8, Canada; (K.K.); (H.B.)
| | - Kamal Kolasangiani
- Institute for Biomedical Engineering, Science and Technology (iBEST), St. Michael’s Hospital & Toronto Metropolitan University, Toronto, ON M5B 1T8, Canada; (K.K.); (H.B.)
- Department of Mechanical and Industrial Engineering, Toronto Metropolitan University, Toronto, ON M5B 2K3, Canada
| | - Siddharth Sadanand
- Department of Electrical, Computer and Biomedical Engineering, Toronto Metropolitan University, Toronto, ON M5B 2K3, Canada; (C.C.); (S.S.)
- Institute for Biomedical Engineering, Science and Technology (iBEST), St. Michael’s Hospital & Toronto Metropolitan University, Toronto, ON M5B 1T8, Canada; (K.K.); (H.B.)
| | - Habiba Bougherara
- Institute for Biomedical Engineering, Science and Technology (iBEST), St. Michael’s Hospital & Toronto Metropolitan University, Toronto, ON M5B 1T8, Canada; (K.K.); (H.B.)
- Department of Mechanical and Industrial Engineering, Toronto Metropolitan University, Toronto, ON M5B 2K3, Canada
| | - Dafna Sussman
- Department of Electrical, Computer and Biomedical Engineering, Toronto Metropolitan University, Toronto, ON M5B 2K3, Canada; (C.C.); (S.S.)
- Institute for Biomedical Engineering, Science and Technology (iBEST), St. Michael’s Hospital & Toronto Metropolitan University, Toronto, ON M5B 1T8, Canada; (K.K.); (H.B.)
- Department of Obstetrics and Gynaecology, University of Toronto, Toronto, ON M5G 1E2, Canada
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13
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Gabalski MA, Smith KR, Hix J, Zinn KR. Comparisons of 3D printed materials for biomedical imaging applications. SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS 2023; 24:2273803. [PMID: 38415266 PMCID: PMC10898812 DOI: 10.1080/14686996.2023.2273803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 10/17/2023] [Indexed: 02/29/2024]
Abstract
In biomedical imaging, it is desirable that custom-made accessories for restraint, anesthesia, and monitoring can be easily cleaned and not interfere with the imaging quality or analyses. With the rise of 3D printing as a form of rapid prototyping or manufacturing for imaging tools and accessories, it is important to understand which printable materials are durable and not likely to interfere with imaging applications. Here, 15 3D printable materials were evaluated for radiodensity, optical properties, simulated wear, and capacity for repeated cleaning and disinfection. Materials that were durable, easily cleaned, and not expected to interfere with CT, PET, or optical imaging applications were identified.
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Affiliation(s)
- Mitchell A Gabalski
- Biomedical Engineering, Michigan State University, East Lansing, MI, USA
- Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI, USA
| | - Kylie R Smith
- Biomedical Engineering, Michigan State University, East Lansing, MI, USA
- Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI, USA
| | - Jeremy Hix
- Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI, USA
- Radiology, Michigan State University, East Lansing, MI, USA
- Advanced Molecular Imaging Facility, Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI, USA
| | - Kurt R Zinn
- Biomedical Engineering, Michigan State University, East Lansing, MI, USA
- Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI, USA
- Radiology, Michigan State University, East Lansing, MI, USA
- Small Animal Clinical Sciences, Michigan State University, East Lansing, MI, USA
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14
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Ashenafi M, Jeong S, Wancura JN, Gou L, Webster MJ, Zheng D. A quick guide on implementing and quality assuring 3D printing in radiation oncology. J Appl Clin Med Phys 2023; 24:e14102. [PMID: 37501315 PMCID: PMC10647979 DOI: 10.1002/acm2.14102] [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: 05/22/2023] [Revised: 06/23/2023] [Accepted: 07/08/2023] [Indexed: 07/29/2023] Open
Abstract
As three-dimensional (3D) printing becomes increasingly common in radiation oncology, proper implementation, usage, and ongoing quality assurance (QA) are essential. While there have been many reports on various clinical investigations and several review articles, there is a lack of literature on the general considerations of implementing 3D printing in radiation oncology departments, including comprehensive process establishment and proper ongoing QA. This review aims to guide radiation oncology departments in effectively using 3D printing technology for routine clinical applications and future developments. We attempt to provide recommendations on 3D printing equipment, software, workflow, and QA, based on existing literature and our experience. Specifically, we focus on three main applications: patient-specific bolus, high-dose-rate (HDR) surface brachytherapy applicators, and phantoms. Additionally, cost considerations are briefly discussed. This review focuses on point-of-care (POC) printing in house, and briefly touches on outsourcing printing via mail-order services.
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Affiliation(s)
- Michael Ashenafi
- Department of Radiation OncologyUniversity of Rochester Medical CenterRochesterNew YorkUSA
| | - Seungkyo Jeong
- Department of Applied MathematicsUniversity of RochesterRochesterNew YorkUSA
| | - Joshua N. Wancura
- Department of Radiation OncologyUniversity of Rochester Medical CenterRochesterNew YorkUSA
| | - Lang Gou
- Department of Radiation OncologyUniversity of Rochester Medical CenterRochesterNew YorkUSA
| | - Matthew J. Webster
- Department of Radiation OncologyUniversity of Rochester Medical CenterRochesterNew YorkUSA
| | - Dandan Zheng
- Department of Radiation OncologyUniversity of Rochester Medical CenterRochesterNew YorkUSA
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15
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Mei K, Pasyar P, Geagan M, Liu LP, Shapira N, Gang GJ, Stayman JW, Noël PB. Design and fabrication of 3D-printed patient-specific soft tissue and bone phantoms for CT imaging. Sci Rep 2023; 13:17495. [PMID: 37840044 PMCID: PMC10577126 DOI: 10.1038/s41598-023-44602-9] [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: 04/17/2023] [Accepted: 10/10/2023] [Indexed: 10/17/2023] Open
Abstract
The objective of this study is to create patient-specific phantoms for computed tomography (CT) that possess accurate densities and exhibit visually realistic image textures. These qualities are crucial for evaluating CT performance in clinical settings. The study builds upon a previously presented 3D printing method (PixelPrint) by incorporating soft tissue and bone structures. We converted patient DICOM images directly into 3D printer instructions using PixelPrint and utilized calcium-doped filament to increase the Hounsfield unit (HU) range. Density was modeled by controlling printing speed according to volumetric filament ratio to emulate attenuation profiles. We designed micro-CT phantoms to demonstrate the reproducibility, and to determine mapping between filament ratios and HU values on clinical CT systems. Patient phantoms based on clinical cervical spine and knee examinations were manufactured and scanned with a clinical spectral CT scanner. The CT images of the patient-based phantom closely resembled original CT images in visual texture and contrast. Micro-CT analysis revealed minimal variations between prints, with an overall deviation of ± 0.8% in filament line spacing and ± 0.022 mm in line width. Measured differences between patient and phantom were less than 12 HU for soft tissue and 15 HU for bone marrow, and 514 HU for cortical bone. The calcium-doped filament accurately represented bony tissue structures across different X-ray energies in spectral CT (RMSE ranging from ± 3 to ± 28 HU, compared to 400 mg/ml hydroxyapatite). In conclusion, this study demonstrated the possibility of extending 3D-printed patient-based phantoms to soft tissue and bone structures while maintaining accurate organ geometry, image texture, and attenuation profiles.
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Affiliation(s)
- Kai Mei
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
| | - Pouyan Pasyar
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Michael Geagan
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Leening P Liu
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Nadav Shapira
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Grace J Gang
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - J Webster Stayman
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Peter B Noël
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Department of Diagnostic and Interventional Radiology, School of Medicine and Klinikum Rechts der Isar, Technical University of Munich, 81675, Munich, Germany
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16
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Marshall H, Selvan T, Ahmad R, Bento M, Veiga C, Sands G, Malone C, King RB, Clark CH, McGarry CK. Evaluation of a novel phantom for the quality assurance of a six-degree-of-freedom couch 3D-printed at multiple centres. Phys Med 2023; 114:103136. [PMID: 37769414 DOI: 10.1016/j.ejmp.2023.103136] [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: 04/03/2023] [Revised: 08/18/2023] [Accepted: 09/13/2023] [Indexed: 09/30/2023] Open
Abstract
This study aimed to validate a bespoke 3D-printed phantom for use in quality assurance (QA) of a 6 degrees-of-freedom (6DoF) treatment couch. A novel phantom design comprising a main body with internal cube structures, was fabricated at five centres using Polylactic Acid (PLA) material, with an additional phantom produced incorporating a PLA-stone hybrid material. Correctional setup shifts were determined using image registration by 3D-3D matching of high HU cube structures between obtained cone-beam computer tomography (CBCT) images to reference CTs, containing cubes with fabricated rotational offsets of 3.5°, 1.5° and -2.5° in rotation, pitch, and roll, respectively. Average rotational setup shifts were obtained for each phantom. The reproducibility of 3D-printing was probed by comparing the internal cube size as well as Hounsfield Units between each of the uniquely produced phantoms. For the five PLA phantoms, the average rot, pitch and roll correctional differences from the fabricated offsets were -0.3 ± 0.2°, -0.2 ± 0.5° and 0.2 ± 0.3° respectively, and for the PLA hybrid these differences were -0.09 ± 0.14°, 0.30 ± 0.00° and 0.03 ± 0.10°. There was found to be no statistically significant difference in average cube size between the five PLA printed phantoms, with the significant difference (P < 0.05) in HU of one phantom compared to the others attributed to setup choice and material density. This work demonstrated the capability producing a novel 3D-printed 6DoF couch QA phantom design, at multiple centres, with each unique model capable of sub-degree couch correction.
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Affiliation(s)
- Hannah Marshall
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, UK.
| | - Tamil Selvan
- Department of Radiotherapy Physics, Northern Ireland Cancer Centre, Belfast Health and Social Care Trust, Belfast, UK
| | - Reem Ahmad
- Department of Medical Physics and Biomedical Engineering, University College London, London, UK
| | - Mariana Bento
- Department of Medical Physics and Biomedical Engineering, University College London, London, UK
| | - Catarina Veiga
- Department of Medical Physics and Biomedical Engineering, University College London, London, UK
| | - Gordon Sands
- Radiotherapy Physics, UCLH NHS Foundation Trust, London, UK
| | - Ciaran Malone
- Radiotherapy Physics, St. Luke's Radiation Oncology Network, Dublin, Ireland
| | - Raymond B King
- Department of Radiotherapy Physics, Northern Ireland Cancer Centre, Belfast Health and Social Care Trust, Belfast, UK
| | - Catharine H Clark
- Department of Medical Physics and Biomedical Engineering, University College London, London, UK; Radiotherapy Physics, UCLH NHS Foundation Trust, London, UK; Metrology for Medical Physics, National Physical Laboratory, Teddington, UK
| | - Conor K McGarry
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, UK; Department of Radiotherapy Physics, Northern Ireland Cancer Centre, Belfast Health and Social Care Trust, Belfast, UK
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17
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Hatamikia S, Jaksa L, Kronreif G, Birkfellner W, Kettenbach J, Buschmann M, Lorenz A. Silicone phantoms fabricated with multi-material extrusion 3D printing technology mimicking imaging properties of soft tissues in CT. Z Med Phys 2023:S0939-3889(23)00076-4. [PMID: 37380561 DOI: 10.1016/j.zemedi.2023.05.007] [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: 12/30/2022] [Revised: 05/20/2023] [Accepted: 05/21/2023] [Indexed: 06/30/2023]
Abstract
Recently, 3D printing has been widely used to fabricate medical imaging phantoms. So far, various rigid 3D printable materials have been investigated for their radiological properties and efficiency in imaging phantom fabrication. However, flexible, soft tissue materials are also needed for imaging phantoms for simulating several clinical scenarios where anatomical deformations is important. Recently, various additive manufacturing technologies have been used to produce anatomical models based on extrusion techniques that allow the fabrication of soft tissue materials. To date, there is no systematic study in the literature investigating the radiological properties of silicone rubber materials/fluids for imaging phantoms fabricated directly by extrusion using 3D printing techniques. The aim of this study was to investigate the radiological properties of 3D printed phantoms made of silicone in CT imaging. To achieve this goal, the radiodensity as described as Hounsfield Units (HUs) of several samples composed of three different silicone printing materials were evaluated by changing the infill density to adjust their radiological properties. A comparison of HU values with a Gammex Tissue Characterization Phantom was performed. In addition, a reproducibility analysis was performed by creating several replicas for specific infill densities. A scaled down anatomical model derived from an abdominal CT was also fabricated and the resulting HU values were evaluated. For the three different silicone materials, a spectrum ranging from -639 to +780 HU was obtained on CT at a scan setting of 120 kVp. In addition, using different infill densities, the printed materials were able to achieve a similar radiodensity range as obtained in different tissue-equivalent inserts in the Gammex phantom (238 HU to -673 HU). The reproducibility results showed good agreement between the HU values of the replicas compared to the original samples, confirming the reproducibility of the printed materials. A good agreement was observed between the HU target values in abdominal CT and the HU values of the 3D-printed anatomical phantom in all tissues.
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Affiliation(s)
- Sepideh Hatamikia
- Austrian Center for Medical Innovation and Technology (ACMIT), Wiener Neustadt, Austria; Research Center for Medical Image Analysis and Artificial Intelligence (MIAAI), Department of Medicine, Danube Private University, Krems, Austria.
| | - Laszlo Jaksa
- Austrian Center for Medical Innovation and Technology (ACMIT), Wiener Neustadt, Austria
| | - Gernot Kronreif
- Austrian Center for Medical Innovation and Technology (ACMIT), Wiener Neustadt, Austria
| | - Wolfgang Birkfellner
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Joachim Kettenbach
- Institute of Diagnostic, Interventional Radiology and Nuclear Medicine, Landesklinikum Wiener Neustadt, Wiener Neustadt, Austria
| | - Martin Buschmann
- Department of Radiation Oncology, Medical University of Vienna/AKH Wien, Vienna, Austria
| | - Andrea Lorenz
- Austrian Center for Medical Innovation and Technology (ACMIT), Wiener Neustadt, Austria
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18
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Breslin T, Paino J, Wegner M, Engels E, Fiedler S, Forrester H, Rennau H, Bustillo J, Cameron M, Häusermann D, Hall C, Krause D, Hildebrandt G, Lerch M, Schültke E. A Novel Anthropomorphic Phantom Composed of Tissue-Equivalent Materials for Use in Experimental Radiotherapy: Design, Dosimetry and Biological Pilot Study. Biomimetics (Basel) 2023; 8:230. [PMID: 37366825 DOI: 10.3390/biomimetics8020230] [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: 04/29/2023] [Revised: 05/26/2023] [Accepted: 05/28/2023] [Indexed: 06/28/2023] Open
Abstract
The production of anthropomorphic phantoms generated from tissue-equivalent materials is challenging but offers an excellent copy of the typical environment encountered in typical patients. High-quality dosimetry measurements and the correlation of the measured dose with the biological effects elicited by it are a prerequisite in preparation of clinical trials with novel radiotherapy approaches. We designed and produced a partial upper arm phantom from tissue-equivalent materials for use in experimental high-dose-rate radiotherapy. The phantom was compared to original patient data using density values and Hounsfield units obtained from CT scans. Dose simulations were conducted for broad-beam irradiation and microbeam radiotherapy (MRT) and compared to values measured in a synchrotron radiation experiment. Finally, we validated the phantom in a pilot experiment with human primary melanoma cells.
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Affiliation(s)
- Thomas Breslin
- Department of Oncology, Clinical Sciences, Lund University, 22185 Lund, Sweden
| | - Jason Paino
- Centre of Medical Radiation Physics, University of Wollongong, Wollongong 2522, Australia
| | - Marie Wegner
- Institute of Product Development and Mechanical Engineering Design, Hamburg University of Technology, 21073 Hamburg, Germany
| | - Elette Engels
- Centre of Medical Radiation Physics, University of Wollongong, Wollongong 2522, Australia
- Australian Synchrotron/ANSTO, Clayton 3168, Australia
| | - Stefan Fiedler
- European Molecular Biology Laboratory (EMBL), Hamburg Outstation, 22607 Hamburg, Germany
| | - Helen Forrester
- School of Science, Royal Melbourne Institute of Technology (RMIT) University, Melbourne 3001, Australia
| | - Hannes Rennau
- Department of Radiooncology, Rostock University Medical Center, 18059 Rostock, Germany
| | - John Bustillo
- Centre of Medical Radiation Physics, University of Wollongong, Wollongong 2522, Australia
| | | | | | | | - Dieter Krause
- Institute of Product Development and Mechanical Engineering Design, Hamburg University of Technology, 21073 Hamburg, Germany
| | - Guido Hildebrandt
- Department of Radiooncology, Rostock University Medical Center, 18059 Rostock, Germany
| | - Michael Lerch
- Centre of Medical Radiation Physics, University of Wollongong, Wollongong 2522, Australia
| | - Elisabeth Schültke
- Department of Radiooncology, Rostock University Medical Center, 18059 Rostock, Germany
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19
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Dąbrowska-Szewczyk E, Zawadzka A, Kowalczyk P, Podgórski R, Saworska G, Głowacki M, Kukołowicz P, Brzozowska B. Low-density 3D-printed boluses with honeycomb infill 3D-printed boluses in radiotherapy. Phys Med 2023; 110:102600. [PMID: 37167778 DOI: 10.1016/j.ejmp.2023.102600] [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: 02/01/2023] [Revised: 04/05/2023] [Accepted: 04/30/2023] [Indexed: 05/13/2023] Open
Abstract
PURPOSE Dosimetric characteristics of 3D-printed plates using different infill percentage and materials was the purpose of our study. METHODS Test plates with 5%, 10%, 15% and 20% honeycomb structure infill were fabricated using TPU and PLA polymers. The Hounsfield unit distribution was determined using a Python script. Percentage Depth Dose (PDD) distribution in the build-up region was measured with the Markus plane-parallel ionization chamber for an open 10x10 cm2 field of 6 MV. PDD was measured at a depth of 1 mm, 5 mm, 10 mm and 15 mm. Measurements were compared with Eclipse treatment planning system calculations using AAA and Acuros XB algorithms. RESULTS The mean HU for CT scans of 3D-printed TPU plates increased with percentage infill increase from -739 HU for 5% to -399 HU for 20%. Differences between the average HU for TPU and PLA did not exceed 2% for all percentage infills. Even using a plate with the lowest infill PDD at 1 mm depth increase from 44.7% (without a plate) to 76.9% for TPU and 76.6% for PLA. Infill percentage did not affect the dose at depths greater than 5 mm. Differences between measurements and TPS calculations were less than 4.1% for both materials, regardless of the infill percentage and depth. CONCLUSIONS The use of 3D-printed light boluses increases the dose in the build-up region, which was shown based on the dosimetric measurements and TPS calculations.
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Affiliation(s)
- Edyta Dąbrowska-Szewczyk
- Biomedical Physics Division, Faculty of Physics, University of Warsaw, 5 L. Pasteur Street, 02-093 Warsaw, Poland; Medical Physics Department, The Maria Skłodowska-Curie National Research Institute of Oncology in Warsaw, 5 WK Roentgen Street, 02-781 Warsaw, Poland
| | - Anna Zawadzka
- Medical Physics Department, The Maria Skłodowska-Curie National Research Institute of Oncology in Warsaw, 5 WK Roentgen Street, 02-781 Warsaw, Poland
| | - Piotr Kowalczyk
- Warsaw University of Technology, Faculty of Chemical and Process Engineering, Department of Biotechnology and Bioprocess Engineering, Waryńskiego 1, 00-645 Warsaw, Poland; Centre of Advanced Materials and Technologies CEZAMAT, Poleczki 19, 02-822 Warsaw, Poland
| | - Rafał Podgórski
- Warsaw University of Technology, Faculty of Chemical and Process Engineering, Department of Biotechnology and Bioprocess Engineering, Waryńskiego 1, 00-645 Warsaw, Poland
| | - Gabriela Saworska
- Biomedical Physics Division, Faculty of Physics, University of Warsaw, 5 L. Pasteur Street, 02-093 Warsaw, Poland
| | - Maksymilian Głowacki
- Biomedical Physics Division, Faculty of Physics, University of Warsaw, 5 L. Pasteur Street, 02-093 Warsaw, Poland
| | - Paweł Kukołowicz
- Medical Physics Department, The Maria Skłodowska-Curie National Research Institute of Oncology in Warsaw, 5 WK Roentgen Street, 02-781 Warsaw, Poland
| | - Beata Brzozowska
- Biomedical Physics Division, Faculty of Physics, University of Warsaw, 5 L. Pasteur Street, 02-093 Warsaw, Poland.
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20
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Mei K, Pasyar P, Geagan M, Liu LP, Shapira N, Gang GJ, Stayman JW, Noël PB. Design and fabrication of 3D-printed patient-specific soft tissue and bone phantoms for CT imaging. RESEARCH SQUARE 2023:rs.3.rs-2828218. [PMID: 37162901 PMCID: PMC10168445 DOI: 10.21203/rs.3.rs-2828218/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The objective of this study is to create patient-specific phantoms for computed tomography (CT) that have realistic image texture and densities, which are critical in evaluating CT performance in clinical settings. The study builds upon a previously presented 3D printing method (PixelPrint) by incorporating soft tissue and bone structures. We converted patient DICOM images directly into 3D printer instructions using PixelPrint and utilized stone-based filament to increase Hounsfield unit (HU) range. Density was modeled by controlling printing speed according to volumetric filament ratio to emulate attenuation profiles. We designed micro-CT phantoms to demonstrate the reproducibility and to determine mapping between filament ratios and HU values on clinical CT systems. Patient phantoms based on clinical cervical spine and knee examinations were manufactured and scanned with a clinical spectral CT scanner. The CT images of the patient-based phantom closely resembled original CT images in texture and contrast. Measured differences between patient and phantom were less than 15 HU for soft tissue and bone marrow. The stone-based filament accurately represented bony tissue structures across different X-ray energies, as measured by spectral CT. In conclusion, this study demonstrated the possibility of extending 3D-printed patient-based phantoms to soft tissue and bone structures while maintaining accurate organ geometry, image texture, and attenuation profiles.
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21
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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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22
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Mei K, Pasyar P, Geagan M, Liu LP, Shapira N, Gang GJ, Stayman JW, Noël PB. Design and fabrication of 3D-printed patient-specific soft tissue and bone phantoms for CT imaging. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.04.17.23288689. [PMID: 37162973 PMCID: PMC10168421 DOI: 10.1101/2023.04.17.23288689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The objective of this study is to create patient-specific phantoms for computed tomography (CT) that have realistic image texture and densities, which are critical in evaluating CT performance in clinical settings. The study builds upon a previously presented 3D printing method (PixelPrint) by incorporating soft tissue and bone structures. We converted patient DICOM images directly into 3D printer instructions using PixelPrint and utilized stone-based filament to increase Hounsfield unit (HU) range. Density was modeled by controlling printing speed according to volumetric filament ratio to emulate attenuation profiles. We designed micro-CT phantoms to demonstrate the reproducibility and to determine mapping between filament ratios and HU values on clinical CT systems. Patient phantoms based on clinical cervical spine and knee examinations were manufactured and scanned with a clinical spectral CT scanner. The CT images of the patient-based phantom closely resembled original CT images in texture and contrast. Measured differences between patient and phantom were less than 15 HU for soft tissue and bone marrow. The stone-based filament accurately represented bony tissue structures across different X-ray energies, as measured by spectral CT. In conclusion, this study demonstrated the possibility of extending 3D-printed patient-based phantoms to soft tissue and bone structures while maintaining accurate organ geometry, image texture, and attenuation profiles.
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Affiliation(s)
- Kai Mei
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Pouyan Pasyar
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Michael Geagan
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Leening P. Liu
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Nadav Shapira
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Grace J. Gang
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - J. Webster Stayman
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Peter B. Noël
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Department of Diagnostic and Interventional Radiology, School of Medicine & Klinikum rechts der Isar, Technical University of Munich, 81675 München, Germany
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23
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Shapira N, Donovan K, Mei K, Geagan M, Roshkovan L, Gang GJ, Abed M, Linna NB, Cranston CP, O'Leary CN, Dhanaliwala AH, Kontos D, Litt HI, Stayman JW, Shinohara RT, Noël PB. Three-dimensional printing of patient-specific computed tomography lung phantoms: a reader study. PNAS NEXUS 2023; 2:pgad026. [PMID: 36909822 PMCID: PMC9992761 DOI: 10.1093/pnasnexus/pgad026] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 12/20/2022] [Accepted: 01/17/2023] [Indexed: 02/04/2023]
Abstract
In modern clinical decision-support algorithms, heterogeneity in image characteristics due to variations in imaging systems and protocols hinders the development of reproducible quantitative measures including for feature extraction pipelines. With the help of a reader study, we investigate the ability to provide consistent ground-truth targets by using patient-specific 3D-printed lung phantoms. PixelPrint was developed for 3D-printing lifelike computed tomography (CT) lung phantoms by directly translating clinical images into printer instructions that control density on a voxel-by-voxel basis. Data sets of three COVID-19 patients served as input for 3D-printing lung phantoms. Five radiologists rated patient and phantom images for imaging characteristics and diagnostic confidence in a blinded reader study. Effect sizes of evaluating phantom as opposed to patient images were assessed using linear mixed models. Finally, PixelPrint's production reproducibility was evaluated. Images of patients and phantoms had little variation in the estimated mean (0.03-0.29, using a 1-5 scale). When comparing phantom images to patient images, effect size analysis revealed that the difference was within one-third of the inter- and intrareader variabilities. High correspondence between the four phantoms created using the same patient images was demonstrated by PixelPrint's production repeatability tests, with greater similarity scores between high-dose acquisitions of the phantoms than between clinical-dose acquisitions of a single phantom. We demonstrated PixelPrint's ability to produce lifelike CT lung phantoms reliably. These phantoms have the potential to provide ground-truth targets for validating the generalizability of inference-based decision-support algorithms between different health centers and imaging protocols and for optimizing examination protocols with realistic patient-based phantoms. Classification: CT lung phantoms, reader study.
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Affiliation(s)
- Nadav Shapira
- Department of Radiology, Perelman School of Medicine of the University of Pennsylvania, 3400 Civic Center, Philadelphia, PA 19104, USA
| | - Kevin Donovan
- Penn Statistics in Imaging and Visualization Center, Department of Biostatistics, Epidemiology and Informatics, University of Pennsylvania, 423 Guardian Drive, Philadelphia, PA 19104, USA
| | - Kai Mei
- Department of Radiology, Perelman School of Medicine of the University of Pennsylvania, 3400 Civic Center, Philadelphia, PA 19104, USA
| | - Michael Geagan
- Department of Radiology, Perelman School of Medicine of the University of Pennsylvania, 3400 Civic Center, Philadelphia, PA 19104, USA
| | - Leonid Roshkovan
- Department of Radiology, Perelman School of Medicine of the University of Pennsylvania, 3400 Civic Center, Philadelphia, PA 19104, USA
| | - Grace J Gang
- Department of Biomedical Engineering, Johns Hopkins University, 720 Rutland Avenue, Baltimore, MD 21205, USA
| | - Mohammed Abed
- Department of Radiology, Perelman School of Medicine of the University of Pennsylvania, 3400 Civic Center, Philadelphia, PA 19104, USA
- Department of Radiology, College of Medicine, Ibn Sina University of Medical and Pharmaceutical Sciences, 79G3+3RR Qadisaya Expy, Baghdad, Iraq
| | - Nathaniel B Linna
- Department of Radiology, Perelman School of Medicine of the University of Pennsylvania, 3400 Civic Center, Philadelphia, PA 19104, USA
| | - Coulter P Cranston
- Department of Radiology, Perelman School of Medicine of the University of Pennsylvania, 3400 Civic Center, Philadelphia, PA 19104, USA
| | - Cathal N O'Leary
- Department of Radiology, Perelman School of Medicine of the University of Pennsylvania, 3400 Civic Center, Philadelphia, PA 19104, USA
| | - Ali H Dhanaliwala
- Department of Radiology, Perelman School of Medicine of the University of Pennsylvania, 3400 Civic Center, Philadelphia, PA 19104, USA
| | - Despina Kontos
- Department of Radiology, Perelman School of Medicine of the University of Pennsylvania, 3400 Civic Center, Philadelphia, PA 19104, USA
| | - Harold I Litt
- Department of Radiology, Perelman School of Medicine of the University of Pennsylvania, 3400 Civic Center, Philadelphia, PA 19104, USA
| | - J Webster Stayman
- Department of Biomedical Engineering, Johns Hopkins University, 720 Rutland Avenue, Baltimore, MD 21205, USA
| | - Russell T Shinohara
- Penn Statistics in Imaging and Visualization Center, Department of Biostatistics, Epidemiology and Informatics, University of Pennsylvania, 423 Guardian Drive, Philadelphia, PA 19104, USA
- Center for Biomedical Image Computing and Analytics (CBICA), Perelman School of Medicine of the University of Pennsylvania, 3700 Hamilton Walk, Philadelphia, PA 19104, USA
| | - Peter B Noël
- Department of Radiology, Perelman School of Medicine of the University of Pennsylvania, 3400 Civic Center, Philadelphia, PA 19104, USA
- Department of Diagnostic and Interventional Radiology, School of Medicine and Klinikum rechts der Isar, Technical University of Munich, Arcisstraße 21, 80333 München, Germany
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24
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An anthropomorphic 3D printed inhomogeneity thorax phantom slab for SBRT commissioning and quality assurance. Phys Eng Sci Med 2023; 46:575-583. [PMID: 36806158 DOI: 10.1007/s13246-023-01233-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Accepted: 02/09/2023] [Indexed: 02/23/2023]
Abstract
Anthropomorphic phantoms with tissue equivalency are required in radiotherapy for quality assurance of imaging and dosimetric processes used in radiotherapy treatments. Commercial phantoms are expensive and provide limited approximation to patient geometry and tissue equivalency. In this study, a 5 cm thick anthropomorphic thoracic slab phantom was designed and 3D printed using models exported from a CT dataset to demonstrate the feasibility of manufacturing anthropomorphic 3D printed phantoms onsite in a clinical radiotherapy department. The 3D printed phantom was manufactured with polylactic acid with an in-fill density of 80% to simulate tissue density and 26% to simulate lung density. A common radio-opacifier, barium sulfate (BaSO4), was added 6% w/w to an epoxy resin mixture to simulate similar HU numbers for bone equivalency. A half-cylindrical shape was cropped away from the spine region to allow insertion of the bone equivalent mixture. Two Gafchromic™ EBT3 film strips were inserted into the 3D printed phantom to measure the delivery of two stereotactic radiotherapy plans targeting lung and bone lesions respectively. Results were analysed within SNC Patient with a low dose threshold of 10% and a gamma criterion of 3%/2 mm and 5%/1 mm. The resulting gamma pass rate across both criterions for lung and bone were ≥ 95% and approximately 85% respectively. Results shows that a cost-effective anthropomorphic 3D printed phantom with realistic heterogeneity simulation can be fabricated in departments with access a suitable 3D printer, which can be used for performing commissioning and quality assurance for stereotactic type radiotherapy to lesions in the presence of heterogeneity.
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25
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Laidlaw J, Earl N, Shavdia N, Davis R, Mayer S, Karaman D, Richtsmeier D, Rodesch PA, Bazalova-Carter M. Design and CT imaging of casper, an anthropomorphic breathing thorax phantom. Biomed Phys Eng Express 2023; 9. [PMID: 36724499 DOI: 10.1088/2057-1976/acb7f7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 02/01/2023] [Indexed: 02/03/2023]
Abstract
The goal of this work was to build an anthropomorphic thorax phantom capable of breathing motion with materials mimicking human tissues in x-ray imaging applications. The thorax phantom, named Casper, was composed of resin (body), foam (lungs), glow polyactic acid (bones) and natural polyactic acid (tumours placed in the lungs). X-ray attenuation properties of all materials prior to manufacturing were evaluated by means of photon-counting computed tomography (CT) imaging on a table-top system. Breathing motion was achieved by a scotch-yoke mechanism with diaphragm motion frequencies of 10-20 rpm and displacements of 1 to 2 cm. Casper was manufactured by means of 3D printing of moulds and ribs and assembled in a complex process. The final phantom was then scanned using a clinical CT scanner to evaluate material CT numbers and the extent of tumour motion. Casper CT numbers were close to human CT numbers for soft tissue (46 HU), ribs (125 HU), lungs (-840 HU) and tumours (-45 HU). For a 2 cm diaphragm displacement the largest tumour displacement was 0.7 cm. The five tumour volumes were accurately assessed in the static CT images with a mean absolute error of 4.3%. Tumour sizes were either underestimated for smaller tumours or overestimated for larger tumours in dynamic CT images due to motion blurring with a mean absolute difference from true volumes of 10.3%. More Casper information including a motion movie and manufacturing data can be downloaded from http://web.uvic.ca/~bazalova/Casper/.
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Affiliation(s)
- Josie Laidlaw
- Department of Mechanical Engineering, University of Victoria, Victoria, British Columbia V8P 5C2, Canada
| | - Nicolas Earl
- Department of Mechanical Engineering, University of Victoria, Victoria, British Columbia V8P 5C2, Canada
| | - Nihal Shavdia
- Department of Mechanical Engineering, University of Victoria, Victoria, British Columbia V8P 5C2, Canada
| | - Rayna Davis
- Department of Mechanical Engineering, University of Victoria, Victoria, British Columbia V8P 5C2, Canada
| | - Sarah Mayer
- Department of Mechanical Engineering, University of Victoria, Victoria, British Columbia V8P 5C2, Canada
| | - Dmitri Karaman
- Axolotl Bioscience, Victoria, British Columbia V8W 2Y2, Canada
| | - Devon Richtsmeier
- Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia V8P 5C2, Canada
| | - Pierre-Antoine Rodesch
- Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia V8P 5C2, Canada
| | - Magdalena Bazalova-Carter
- Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia V8P 5C2, Canada
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26
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Motovilova E, Aronowitz E, Vincent J, Shin J, Tan ET, Robb F, Taracila V, Sneag DB, Dyke JP, Winkler SA. Silicone-based materials with tailored MR relaxation characteristics for use in reduced coil visibility and in tissue-mimicking phantom design. Med Phys 2023. [PMID: 36737839 DOI: 10.1002/mp.16255] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 12/24/2022] [Accepted: 01/15/2023] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND The development of materials with tailored signal intensity in MR imaging is critically important both for the reduction of signal from non-tissue hardware, as well as for the construction of tissue-mimicking phantoms. Silicone-based phantoms are becoming more popular due to their structural stability, stretchability, longer shelf life, and ease of handling, as well as for their application in dynamic imaging of physiology in motion. Moreover, silicone can be also used for the design of stretchable receive radio-frequency (RF) coils. PURPOSE Fabrication of materials with tailored signal intensity for MRI requires knowledge of precise T1 and T2 relaxation times of the materials used. In order to increase the range of possible relaxation times, silicone materials can be doped with gadolinium (Gd). In this work, we aim to systematically evaluate relaxation properties of Gd-doped silicone material at a broad range of Gd concentrations and at three clinically relevant magnetic field strengths (1.5 T, 3 T, and 7 T). We apply the findings for rendering silicone substrates of stretchable receive RF coils less visible in MRI. Moreover, we demonstrate early stage proof-of-concept applicability in tissue-mimicking phantom development. MATERIALS AND METHODS Ten samples of pure and Gd-doped Ecoflex silicone polymer samples were prepared with various Gd volume ratios ranging from 1:5000 to 1:10, and studied using 1.5 T and 3 T clinical and 7 T preclinical scanners. T1 and T2 relaxation times of each sample were derived by fitting the data to Bloch signal intensity equations. A receive coil made from Gd-doped Ecoflex silicone polymer was fabricated and evaluated in vitro at 3 T. RESULTS With the addition of a Gd-based contrast agent, it is possible to significantly change T2 relaxation times of Ecoflex silicone polymer (from 213 ms to 20 ms at 1.5 T; from 135 ms to 17 ms at 3 T; and from 111.4 ms to 17.2 ms at 7 T). T1 relaxation time is less affected by the introduction of the contrast agent (changes from 608 ms to 579 ms; from 802.5 ms to 713 ms at 3 T; from 1276 ms to 979 ms at 7 T). First results also indicate that liver, pancreas, and white matter tissues can potentially be closely mimicked using this phantom preparation technique. Gd-doping reduces the appearance of the silicone-based coil substrate during the MR scan by up to 81%. CONCLUSIONS Gd-based contrast agents can be effectively used to create Ecoflex silicone polymer-based phantoms with tailored T2 relaxation properties. The relative low cost, ease of preparation, stretchability, mechanical stability, and long shelf life of Ecoflex silicone polymer all make it a good candidate for "MR invisible" coil development and bears promise for tissue-mimicking phantom development applicability.
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Affiliation(s)
- Elizaveta Motovilova
- Department of Radiology, Weill Cornell Medicine, New York, New York, USA.,Department of Radiology, Hospital for Special Surgery, New York, New York, USA
| | - Eric Aronowitz
- Department of Radiology, Weill Cornell Medicine, New York, New York, USA
| | | | - James Shin
- Department of Radiology, Weill Cornell Medicine, New York, New York, USA
| | - Ek Tsoon Tan
- Department of Radiology, Hospital for Special Surgery, New York, New York, USA
| | | | | | - Darryl B Sneag
- Department of Radiology, Hospital for Special Surgery, New York, New York, USA
| | - Jonathan P Dyke
- Department of Radiology, Weill Cornell Medicine, New York, New York, USA
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27
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Utilizing Additive Manufacturing to Produce Organ Mimics and Imaging Phantoms. SURGERIES 2023. [DOI: 10.3390/surgeries4010008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The complex geometries and material properties necessary for generating accurate organ mimics require new procedures and methods to fully utilize current technologies. The increased accessibility of 3D printers, along with more specialized bioprinters, allow the creation of highly tunable models of various body parts. Three-dimensional printing can reduce lead-time on custom parts, produce structures based on imaging data in patients, and generate a test bench for novel surgical methods. This technical note will cover three unique case studes and offer insights for how 3D printing can be used for lab research. Each case follows a unique design process in comparison to traditional manufacturing workflows as they required significantly more iterative design. The strengths of different printing technologies, design choices, and structural/chemical requirements all influence the design process. Utilization of in-house manufacturing allows for greater flexibility and lower lead-times for novel research applications. Detailed discussions of these design processes will help reduce some of the major barriers to entry for these technologies and provide options for researchers working in the field.
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28
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Dinh J, Yamashita A, Kang H, Gioux S, Choi HS. Optical Tissue Phantoms for Quantitative Evaluation of Surgical Imaging Devices. ADVANCED PHOTONICS RESEARCH 2023; 4:2200194. [PMID: 36643020 PMCID: PMC9838008 DOI: 10.1002/adpr.202200194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Optical tissue phantoms (OTPs) have been extensively applied to the evaluation of imaging systems and surgical training. Due to their human tissue-mimicking characteristics, OTPs can provide accurate optical feedback on the performance of image-guided surgical instruments, simulating the biological sizes and shapes of human organs, and preserving similar haptic responses of original tissues. This review summarizes the essential components of OTPs (i.e., matrix, scattering and absorbing agents, and fluorophores) and the various manufacturing methods currently used to create suitable tissue-mimicking phantoms. As photobleaching is a major challenge in OTP fabrication and its feedback accuracy, phantom photostability and how the photobleaching phenomenon can affect their optical properties are discussed. Consequently, the need for novel photostable OTPs for the quantitative evaluation of surgical imaging devices is emphasized.
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Affiliation(s)
- Jason Dinh
- Gordon Center for Medical Imaging, Department of Radiology, Harvard Medical School, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Atsushi Yamashita
- Gordon Center for Medical Imaging, Department of Radiology, Harvard Medical School, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Homan Kang
- Gordon Center for Medical Imaging, Department of Radiology, Harvard Medical School, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Sylvain Gioux
- Intuitive Surgical Sàrl, 1170 Aubonne, Switzerland
- ICube Laboratory, University of Strasbourg, 67081 Strasbourg, France
| | - Hak Soo Choi
- Gordon Center for Medical Imaging, Department of Radiology, Harvard Medical School, Massachusetts General Hospital, Boston, MA 02114, USA
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29
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Okkalidis N, Bliznakova K. A voxel-by-voxel method for mixing two filaments during a 3D printing process for soft-tissue replication in an anthropomorphic breast phantom. Phys Med Biol 2022; 67. [PMID: 36541511 DOI: 10.1088/1361-6560/aca640] [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: 12/14/2021] [Accepted: 11/25/2022] [Indexed: 11/26/2022]
Abstract
Objective. In this study, a novel voxel-by-voxel mixing method is presented, according to which two filaments of different material are combined during the three dimensional (3D) printing process.Approach. In our approach, two types of filaments were used for the replication of soft-tissues, a polylactic acid (PLA) filament and a polypropylene (PP) filament. A custom-made software was used, while a series of breast patient CT scan images were directly associated to the 3D printing process. Each phantom´s layer was printed twice, once with the PLA filament and a second time with the PP filament. For each material, the filament extrusion rate was controlled voxel-by-voxel and was based on the Hounsfield units (HU) of the imported CT images. The phantom was scanned at clinical CT, breast tomosynthesis and micro CT facilities, as the major processing was performed on data from the CT. A side by side comparison between patient´s and phantom´s CT slices by means of profile and histogram comparison was accomplished. Further, in case of profile comparison, the Pearson´s coefficients were calculated.Main results. The visual assessment of the distribution of the glandular tissue in the CT slices of the printed breast anatomy showed high degree of radiological similarity to the corresponding patient´s glandular distribution. The profile plots´ comparison showed that the HU of the replicated and original patient soft tissues match adequately. In overall, the Pearson´s coefficients were above 0.91, suggesting a close match of the CT images of the phantom with those of the patient. The overall HU were close in terms of HU ranges. The HU mean, median and standard deviation of the original and the phantom CT slices were -149, -167, ±65 and -121, -130, ±91, respectively.Significance. The results suggest that the proposed methodology is appropriate for manufacturing of anthropomorphic soft tissue phantoms for x-ray imaging and dosimetry purposes, since it may offer an accurate replication of these tissues.
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Affiliation(s)
- Nikiforos Okkalidis
- Research Institute, Medical University of Varna, Bulgaria.,Morphé, Praxitelous 1, Thessaloniki, Greece
| | - Kristina Bliznakova
- Department of Medical Equipment, Electronic and Information Technologies in Healthcare, Medical University of Varna, Varna, Bulgaria
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30
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Implementation of an In-House 3D Manufacturing Unit in a Public Hospital’s Radiology Department. Healthcare (Basel) 2022; 10:healthcare10091791. [PMID: 36141403 PMCID: PMC9498605 DOI: 10.3390/healthcare10091791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 08/30/2022] [Accepted: 09/14/2022] [Indexed: 11/23/2022] Open
Abstract
Objective: Three-dimensional printing has become a leading manufacturing technique in healthcare in recent years. Doubts in published studies regarding the methodological rigor and cost-effectiveness and stricter regulations have stopped the transfer of this technology in many healthcare organizations. The aim of this study was the evaluation and implementation of a 3D printing technology service in a radiology department. Methods: This work describes a methodology to implement a 3D printing service in a radiology department of a Spanish public hospital, considering leadership, training, workflow, clinical integration, quality processes and usability. Results: The results correspond to a 6-year period, during which we performed up to 352 cases, requested by 85 different clinicians. The training, quality control and processes required for the scaled implementation of an in-house 3D printing service are also reported. Conclusions: Despite the maturity of the technology and its impact on the clinic, it is necessary to establish new workflows to correctly implement them into the strategy of the health organization, adjusting it to the needs of clinicians and to their specific resources. Significance: This work allows hospitals to bridge the gap between research and 3D printing, setting up its transfer to clinical practice and using implementation methodology for decision support.
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31
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X-ray attenuation of bone, soft and adipose tissue in CT from 70 to 140 kV and comparison with 3D printable additive manufacturing materials. Sci Rep 2022; 12:14580. [PMID: 36028638 PMCID: PMC9418162 DOI: 10.1038/s41598-022-18741-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 08/18/2022] [Indexed: 11/17/2022] Open
Abstract
Additive manufacturing and 3D printing are widely used in medical imaging to produce phantoms for image quality optimization, imaging protocol definition, comparison of image quality between different imaging systems, dosimetry, and quality control. Anthropomorphic phantoms mimic tissues and contrasts in real patients with regard to X-ray attenuation, as well as dependence on X-ray spectra. If used with different X-ray energies, or to optimize the spectrum for a certain procedure, the energy dependence of the attenuation must replicate the corresponding energy dependence of the tissues mimicked, or at least be similar. In the latter case the materials’ Hounsfield values need to be known exactly to allow to correct contrast and contrast to noise ratios accordingly for different beam energies. Fresh bovine and porcine tissues including soft and adipose tissues, and hard tissues from soft spongious bone to cortical bone were scanned at different energies, and reference values of attenuation in Hounsfield units (HU) determined. Mathematical model equations describing CT number dependence on kV for bones of arbitrary density, and for adipose tissues are derived. These data can be used to select appropriate phantom constituents, compare CT values with arbitrary phantom materials, and calculate correction factors for phantoms consisting of materials with an energy dependence different to the tissues. Using data on a wide number of additive manufacturing and 3D printing materials, CT numbers and their energy dependence were compared to those of the tissues. Two commercially available printing filaments containing calcium carbonate powder imitate bone tissues with high accuracy at all kV values. Average adipose tissue can be duplicated by several off-the-shelf printing polymers. Since suitable printing materials typically exhibit a too high density for the desired attenuation of especially soft tissues, controlled density reduction by underfilling might improve tissue equivalence.
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32
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Okkalidis N. 3D printing methods for radiological anthropomorphic phantoms. Phys Med Biol 2022; 67. [PMID: 35830787 DOI: 10.1088/1361-6560/ac80e7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Accepted: 07/13/2022] [Indexed: 01/06/2023]
Abstract
Three dimensional (3D) printing technology has been widely evaluated for the fabrication of various anthropomorphic phantoms during the last couple of decades. The demand for such high quality phantoms is constantly rising and gaining an ever-increasing interest. Although, in a short time 3D printing technology provided phantoms with more realistic features when compared to the previous conventional methods, there are still several aspects to be explored. One of these aspects is the further development of the current 3D printing methods and software devoted to radiological applications. The current 3D printing software and methods usually employ 3D models, while the direct association of medical images with the 3D printing process is needed in order to provide results of higher accuracy and closer to the actual tissues' texture. Another aspect of high importance is the development of suitable printing materials. Ideally, those materials should be able to emulate the entire range of soft and bone tissues, while still matching the human's anatomy. Five types of 3D printing methods have been mainly investigated so far: (a) solidification of photo-curing materials; (b) deposition of melted plastic materials; (c) printing paper-based phantoms with radiopaque ink; (d) melting or binding plastic powder; and (e) bio-printing. From the first and second category, polymer jetting technology and fused filament fabrication (FFF), also known as fused deposition modelling (FDM), are the most promising technologies for the fulfilment of the requirements of realistic and radiologically equivalent anthropomorphic phantoms. Another interesting approach is the fabrication of radiopaque paper-based phantoms using inkjet printers. Although, this may provide phantoms of high accuracy, the utilized materials during the fabrication process are restricted to inks doped with various contrast materials. A similar condition applies to the polymer jetting technology, which despite being quite fast and very accurate, the utilized materials are restricted to those capable of polymerization. The situation is better for FFF/FDM 3D printers, since various compositions of plastic filaments with external substances can be produced conveniently. Although, the speed and accuracy of this 3D printing method are lower compared to the others, the relatively low-cost, constantly improving resolution, sufficient printing volume and plethora of materials are quite promising for the creation of human size heterogeneous phantoms and their adaptation to the treatment procedures of patients in the current health systems.
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Affiliation(s)
- Nikiforos Okkalidis
- Research Institute, Medical University of Varna, Bulgaria.,Morphé, Praxitelous 1, Thessaloniki, Greece
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Simpson-Page E, Coogan P, Kron T, Lowther N, Murray R, Noble C, Smith I, Wilks R, Crowe SB. Webinar and survey on quality management principles within the Australian and New Zealand ACPSEM Workforce. Phys Eng Sci Med 2022; 45:679-685. [PMID: 35834171 DOI: 10.1007/s13246-022-01160-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Healthcare relies upon the accurate and safe delivery of patient care. This is only achievable when systems are developed to ensure high quality, robust outcomes, for instance quality management systems. The concept of quality management can take on a different meaning depending on the context in which it is found. To add complication, the amount of education required for quality management will vary depending on one's exposure to the implementation of quality systems. In part to address these issues, the Australasian College of Physical Scientists and Engineers in Medicine (ACPSEM) Queensland Branch held a quality management webinar for members and non-members across Australia and New Zealand. The purpose of the webinar was to educate and facilitate discussion regarding the application of quality management principles for the ACPSEM profession. In conjunction, a pre- and post-webinar survey was conducted to gain an insight into existing knowledge and attitudes within the professions governed by the ACPSEM and students undertaking related studies. This paper authored by the webinar speakers reintroduces the quality management principles that were discussed in webinar, exemplifies the importance of quality management skills within the ACPSEM professions and presents the results of the surveys, promoting the need for more educational resources on quality management tools.
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Affiliation(s)
- Emily Simpson-Page
- Cancer Care Services, Royal Brisbane and Women's Hospital, Brisbane, Australia.
| | - Paul Coogan
- Q-TRaCE, Department of Nuclear Medicine & Specialised PET Services Queensland, Royal Brisbane and Women's Hospital, Brisbane, Australia
| | - Tomas Kron
- Physical Sciences Department, Peter MacCallum Cancer Centre, Melbourne, Australia
| | - Nicholas Lowther
- Wellington Blood & Cancer Centre, Wellington Hospital, Wellington, New Zealand
| | - Rebecca Murray
- Herston Biofabrication Institute, Metro North Hospital and Health Service, Brisbane, Australia
| | - Christopher Noble
- Department of Radiation Oncology, Princess Alexandra Hospital, Brisbane, Australia
| | - Ian Smith
- St. Andrews War Memorial Hospital, Brisbane, Australia
| | - Rachael Wilks
- Cancer Care Services, Royal Brisbane and Women's Hospital, Brisbane, Australia.,Herston Biofabrication Institute, Metro North Hospital and Health Service, Brisbane, Australia.,School of Information Technology and Electrical Engineering, University of Queensland, Brisbane, Australia
| | - Scott B Crowe
- Cancer Care Services, Royal Brisbane and Women's Hospital, Brisbane, Australia.,Herston Biofabrication Institute, Metro North Hospital and Health Service, Brisbane, Australia.,School of Information Technology and Electrical Engineering, University of Queensland, Brisbane, Australia.,School of Chemistry and Physics, Queensland University of Technology, Brisbane, Australia
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Adam DP, Grudzinski J, Bormett I, Cox BL, Marsh IR, Bradshaw TJ, Harari PM, Bednarz B. Validation of Monte Carlo 131 I radiopharmaceutical dosimetry workflow using a 3D printed anthropomorphic head and neck phantom. Med Phys 2022; 49:5491-5503. [PMID: 35607296 PMCID: PMC9388595 DOI: 10.1002/mp.15699] [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: 11/05/2021] [Revised: 04/11/2022] [Accepted: 04/14/2022] [Indexed: 11/11/2022] Open
Abstract
Purpose Approximately 50% of head and neck cancer (HNC) patients will experience loco‐regional disease recurrence following initial courses of therapy. Retreatment with external beam radiotherapy (EBRT) is technically challenging and may be associated with a significant risk of irreversible damage to normal tissues. Radiopharmaceutical therapy (RPT) is a potential method to treat recurrent HNC in conjunction with EBRT. Phantoms are used to calibrate and add quantification to nuclear medicine images, and anthropomorphic phantoms can account for both the geometrical and material composition of the head and neck. In this study, we present the creation of an anthropomorphic, head and neck, nuclear medicine phantom, and its characterization for the validation of a Monte Carlo, SPECT image‐based, 131I RPT dosimetry workflow. Methods 3D‐printing techniques were used to create the anthropomorphic phantom from a patient CT dataset. Three 131I SPECT/CT imaging studies were performed using a homogeneous, Jaszczak, and an anthropomorphic phantom to quantify the SPECT images using a GE Optima NM/CT 640 with a high energy general purpose collimator. The impact of collimator detector response (CDR) modeling and volume‐based partial volume corrections (PVCs) upon the absorbed dose was calculated using an image‐based, Geant4 Monte Carlo RPT dosimetry workflow and compared against a ground truth scenario. Finally, uncertainties were quantified in accordance with recent EANM guidelines. Results The 3D‐printed anthropomorphic phantom was an accurate re‐creation of patient anatomy including bone. The extrapolated Jaszczak recovery coefficients were greater than that of the 3D‐printed insert (∼22.8 ml) for both the CDR and non‐CDR cases (with CDR: 0.536 vs. 0.493, non‐CDR: 0.445 vs. 0.426, respectively). Utilizing Jaszczak phantom PVCs, the absorbed dose was underpredicted by 0.7% and 4.9% without and with CDR, respectively. Utilizing anthropomorphic phantom recovery coefficient overpredicted the absorbed dose by 3% both with and without CDR. All dosimetry scenarios that incorporated PVC were within the calculated uncertainty of the activity. The uncertainties in the cumulative activity ranged from 23.6% to 106.4% for Jaszczak spheres ranging in volume from 0.5 to 16 ml. Conclusion The accuracy of Monte Carlo‐based dosimetry for 131I RPT in HNC was validated with an anthropomorphic phantom. In this study, it was found that Jaszczak‐based PVCs were sufficient. Future applications of the phantom could involve 3D printing and characterizing patient‐specific volumes for more personalized RPT dosimetry estimates.
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Affiliation(s)
- David P Adam
- Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, 53705
| | - Joseph Grudzinski
- Department of Radiology, University of Wisconsin-Madison, Madison, WI, 53705
| | - Ian Bormett
- Morgridge Institute for Research, University of Wisconsin-Madison, Madison, WI, 53705
| | - Benjamin L Cox
- Morgridge Institute for Research, University of Wisconsin-Madison, Madison, WI, 53705
| | - Ian R Marsh
- Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, 53705
| | - Tyler J Bradshaw
- Department of Radiology, University of Wisconsin-Madison, Madison, WI, 53705
| | - Paul M Harari
- Department of Human Oncology, University of Wisconsin-Madison, Madison, WI, 53705
| | - Bryan Bednarz
- Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, 53705
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K S, E JJS. Studies on the tissue and water equivalence of some 3D printing materials and dosimeters. Radiat Phys Chem Oxf Engl 1993 2022. [DOI: 10.1016/j.radphyschem.2022.110259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Dosimetry procedure to verify dose in High Dose Rate (HDR) brachytherapy treatment of cancer patients: A systematic review. Phys Med 2022; 96:70-80. [DOI: 10.1016/j.ejmp.2022.02.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 02/18/2022] [Accepted: 02/21/2022] [Indexed: 01/12/2023] Open
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Rinaldi L, Pezzotta F, Santaniello T, De Marco P, Bianchini L, Origgi D, Cremonesi M, Milani P, Mariani M, Botta F. HeLLePhant: A phantom mimicking non-small cell lung cancer for texture analysis in CT images. Phys Med 2022; 97:13-24. [PMID: 35334407 DOI: 10.1016/j.ejmp.2022.03.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 02/01/2022] [Accepted: 03/14/2022] [Indexed: 01/06/2023] Open
Abstract
PURPOSE Phantoms mimicking human tissue heterogeneity and intensity are required to establish radiomic features robustness in Computed Tomography (CT) images. We developed inserts with two different techniques for the radiomic study of Non-Small Cell Lung Cancer (NSCLC) lesions. METHODS We developed two insert prototypes: two 3D-printed made of glycol-modified polyethylene terephthalate (PET-G), and nine with sodium polyacrylate plus iodinated contrast medium. The inserts were put in a handcraft phantom (HeLLePhant). We also analysed four materials of a commercial homogeneous phantom (Catphan® 424) and collected 29 NSCLC patients for comparison. All the CT acquisitions were performed with the same clinical protocol and scanner at 120kVp. The HeLLePhant phantom was scanned ten times in fixed condition at 120kVp and 100kVp for repeatability investigation. We extracted 153 radiomic features using Pyradiomics. To compare the features between phantoms and patients, we computed how many phantom features fell in the range between 10th and 90th percentile of the corresponding patient values. We deemed repeatable the features with a coefficient of variation (CV) less than or equal to 0.10. RESULTS The best similarity with the patients was obtained with the polyacrylate inserts (55.6-90.2%), the worst with Catphan (15.7-19.0%). For the PET-G inserts 35.3% and 36.6% of the features match the patient range. We found high repeatability for all the inserts of the HeLLePhant phantom (74.3-100% at 120kVp, 75.7-97.9% at 100kVp), and observed a texture dependency in repeatability. CONCLUSIONS Our study shows a promising way to construct heterogeneous inserts mimicking a target tissue for radiomic studies.
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Affiliation(s)
- Lisa Rinaldi
- Department of Physics, Università degli Studi di Pavia and INFN, via Bassi 6, 27100 Pavia, Italy; Radiation Research Unit, IEO, European Institute of Oncology IRCCS, via Ripamonti 435, 20141 Milan, Italy.
| | - Federico Pezzotta
- CIMaINa, Department of Physics, Università degli Studi di Milano, via Celoria 16, 20133, Milan, Italy
| | - Tommaso Santaniello
- CIMaINa, Department of Physics, Università degli Studi di Milano, via Celoria 16, 20133, Milan, Italy
| | - Paolo De Marco
- Medical Physics Unit, IEO European Institute of Oncology IRCCS, via Ripamonti 435, 20141 Milan, Italy
| | - Linda Bianchini
- Department of Physics, Università degli Studi di Milano, via Celoria 16, 20133, Milan, Italy
| | - Daniela Origgi
- Medical Physics Unit, IEO European Institute of Oncology IRCCS, via Ripamonti 435, 20141 Milan, Italy
| | - Marta Cremonesi
- Radiation Research Unit, IEO, European Institute of Oncology IRCCS, via Ripamonti 435, 20141 Milan, Italy
| | - Paolo Milani
- CIMaINa, Department of Physics, Università degli Studi di Milano, via Celoria 16, 20133, Milan, Italy
| | - Manuel Mariani
- Department of Physics, Università degli Studi di Pavia and INFN, via Bassi 6, 27100 Pavia, Italy
| | - Francesca Botta
- Medical Physics Unit, IEO European Institute of Oncology IRCCS, via Ripamonti 435, 20141 Milan, Italy
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Kron T, Fox C, Ebert MA, Thwaites D. Quality management in radiotherapy treatment delivery. J Med Imaging Radiat Oncol 2022; 66:279-290. [PMID: 35243785 DOI: 10.1111/1754-9485.13348] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 10/29/2021] [Indexed: 12/17/2022]
Abstract
Radiation Oncology continues to rely on accurate delivery of radiation, in particular where patients can benefit from more modulated and hypofractioned treatments that can deliver higher dose to the target while optimising dose to normal structures. These deliveries are more complex, and the treatment units are more computerised, leading to a re-evaluation of quality assurance (QA) to test a larger range of options with more stringent criteria without becoming too time and resource consuming. This review explores how modern approaches of risk management and automation can be used to develop and maintain an effective and efficient QA programme. It considers various tools to control and guide radiation delivery including image guidance and motion management. Links with typical maintenance and repair activities are discussed, as well as patient-specific quality control activities. It is demonstrated that a quality management programme applied to treatment delivery can have an impact on individual patients but also on the quality of treatment techniques and future planning. Developing and customising a QA programme for treatment delivery is an important part of radiotherapy. Using modern multidisciplinary approaches can make this also a useful tool for department management.
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Affiliation(s)
- Tomas Kron
- Department of Physical Sciences, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia.,Sir Peter MacCallum Institute of Oncology, Melbourne University, Melbourne, Victoria, Australia.,Centre for Medical Radiation Physics, University of Wollongong, Wollongong, New South Wales, Australia
| | - Chris Fox
- Department of Physical Sciences, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia
| | - Martin A Ebert
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, New South Wales, Australia.,Department of Radiation Oncology, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia.,School of Physics, Mathematics and Computing, University of Western Australia, Perth, Western Australia, Australia.,5D Clinics, Perth, Western Australia, Australia
| | - David Thwaites
- Institute of Medical Physics, School of Physics, University of Sydney, Sydney, New South Wales, Australia.,Medical Physics Group, Leeds Institute of Cardiovascular and Metabolic Medicine and Leeds Institute of Medical Research, University of Leeds, Leeds, UK
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Hatamikia S, Kronreif G, Unger A, Oberoi G, Jaksa L, Unger E, Koschitz S, Gulyas I, Irnstorfer N, Buschmann M, Kettenbach J, Birkfellner W, Lorenz A. 3D printed patient-specific thorax phantom with realistic heterogenous bone radiopacity using filament printer technology. Z Med Phys 2022; 32:438-452. [PMID: 35221154 PMCID: PMC9948829 DOI: 10.1016/j.zemedi.2022.02.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 12/17/2021] [Accepted: 02/01/2022] [Indexed: 12/11/2022]
Abstract
Current medical imaging phantoms are usually limited by simplified geometry and radiographic skeletal homogeneity, which confines their usage for image quality assessment. In order to fabricate realistic imaging phantoms, replication of the entire tissue morphology and the associated CT numbers, defined as Hounsfield Unit (HU) is required. 3D printing is a promising technology for the production of medical imaging phantoms with accurate anatomical replication. So far, the majority of the imaging phantoms using 3D printing technologies tried to mimic the average HU of soft tissue human organs. One important aspect of the anthropomorphic imaging phantoms is also the replication of realistic radiodensities for bone tissues. In this study, we used filament printing technology to develop a CT-derived 3D printed thorax phantom with realistic bone-equivalent radiodensity using only one single commercially available filament. The generated thorax phantom geometry closely resembles a patient and includes direct manufacturing of bone structures while creating life-like heterogeneity within bone tissues. A HU analysis as well as a physical dimensional comparison were performed in order to evaluate the density and geometry agreement between the proposed phantom and the corresponding CT data. With the achieved density range (-482 to 968 HU) we could successfully mimic the realistic radiodensity of the bone marrow as well as the cortical bone for the ribs, vertebral body and dorsal vertebral column in the thorax skeleton. In addition, considering the large radiodensity range achieved a full thorax imaging phantom mimicking also soft tissues can become feasible. The physical dimensional comparison using both Extrema Analysis and Collision Detection methods confirmed a mean surface overlap of 90% and a mean volumetric overlap of 84,56% between the patient and phantom model. Furthermore, the reproducibility analyses revealed a good geometry and radiodensity duplicability in 24 printed cylinder replicas. Thus, according to our results, the proposed additively manufactured anthropomorphic thorax phantom has the potential to be efficiently used for validation of imaging- and radiation-based procedures in precision medicine.
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Affiliation(s)
- Sepideh Hatamikia
- Austrian Center for Medical Innovation and Technology, Wiener Neustadt, Austria; Danube Private University, 3500 Krems an der Donau, Austria; Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria.
| | - Gernot Kronreif
- Austrian Center for Medical Innovation and Technology, Wiener Neustadt, Austria
| | - Alexander Unger
- Austrian Center for Medical Innovation and Technology, Wiener Neustadt, Austria
| | - Gunpreet Oberoi
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Laszlo Jaksa
- Austrian Center for Medical Innovation and Technology, Wiener Neustadt, Austria
| | - Ewald Unger
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Stefan Koschitz
- Austrian Center for Medical Innovation and Technology, Wiener Neustadt, Austria
| | - Ingo Gulyas
- Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria
| | - Nikolaus Irnstorfer
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-guided Therapy at the Medical University of Vienna
| | - Martin Buschmann
- Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria
| | - Joachim Kettenbach
- Institute of Diagnostic, Interventional Radiology and Nuclear Medicine, Landesklinikum Wiener Neustadt, Wiener Neustadt, Austria
| | - Wolfgang Birkfellner
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Andrea Lorenz
- Austrian Center for Medical Innovation and Technology, Wiener Neustadt, Austria
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Tan HQ, Koh CWY, Tan LKR, Lew KS, Chua CGA, Ang KW, Lee JCL, Park SY. A transit portal dosimetry method for respiratory gating quality assurance with a dynamic 3D printed tumor phantom. J Appl Clin Med Phys 2022; 23:e13560. [PMID: 35147283 PMCID: PMC9121038 DOI: 10.1002/acm2.13560] [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: 07/27/2021] [Revised: 12/27/2021] [Accepted: 01/29/2022] [Indexed: 11/21/2022] Open
Abstract
Backgrounds Respiratory gating is one of the motion management techniques that is used to deliver radiation dose to a tumor at a specific position under free breathing. However, due to the dynamic feedback process of this approach, regular equipment quality assurance (QA) and patient‐specific QA checks need to be performed. This work proposes a new QA methodology using electronic portal imaging detector (EPID) to determine the target localization accuracy of phase gating. Methods QA tools comprising 3D printed spherical tumor phantoms, programmable stages, and an EPID detector are characterized and assembled. Algorithms for predicting portal dose (PD) through moving phantoms are developed and verified using gamma analysis for two spherical tumor phantoms (2 cm and 4 cm), two different 6 MV volumetric modulated arc therapy plans, and two different gating windows (30%–70% and 40%–60%). Comparison between the two gating windows is then performed using the Wilcoxon signed‐rank test. An optimizer routine, which is used to determine the optimal window, based on maximal gamma passing rate (GPR), was applied to an actual breathing curve and breathing plan. This was done to ascertain if our method yielded a similar result with the actual gating window. Results High GPRs of more than 97% and 91% were observed when comparing the predicted PD with the measured PD in moving phantom at 2 mm/2% and 1 mm/1% levels, respectively. Analysis of gamma heatmaps shows an excellent agreement with the tumor phantom. The GPR of 40%–60% PD was significantly lower than that of the 30%–70% PD at the 1 mm/1% level (p = 0.0064). At the 2 mm/2% level, no significant differences were observed. The optimizer routine could accurately predict the center of the gating window to within a 10% range. Conclusion We have successfully performed and verified a new method for QA with the use of a moving phantom with EPID for phase gating with real‐time position management.
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Affiliation(s)
- Hong Qi Tan
- Division of Radiation Oncology, National Cancer Centre, Singapore, Singapore
| | - Calvin Wei Yang Koh
- Division of Radiation Oncology, National Cancer Centre, Singapore, Singapore
| | - Lloyd Kuan Rui Tan
- Division of Radiation Oncology, National Cancer Centre, Singapore, Singapore
| | - Kah Seng Lew
- Division of Radiation Oncology, National Cancer Centre, Singapore, Singapore
| | | | - Khong Wei Ang
- Division of Radiation Oncology, National Cancer Centre, Singapore, Singapore
| | - James Cheow Lei Lee
- Division of Radiation Oncology, National Cancer Centre, Singapore, Singapore.,Division of Physics and Applied Physics, Nanyang Technological University, Singapore, Singapore
| | - Sung Yong Park
- Division of Radiation Oncology, National Cancer Centre, Singapore, Singapore.,Oncology Academic Clinical Programme, Duke-NUS Medical School, Singapore, Singapore
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Dukov N, Bliznakova K, Okkalidis N, Teneva T, Encheva E, Bliznakov Z. Thermoplastic 3D printing technology using a single filament for producing realistic patient-derived breast models. Phys Med Biol 2022; 67. [PMID: 35038693 DOI: 10.1088/1361-6560/ac4c30] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 01/17/2022] [Indexed: 12/29/2022]
Abstract
Objective. This work describes an approach for producing physical anthropomorphic breast phantoms from clinical patient data using three-dimensional (3D) fused-deposition modelling (FDM) printing.Approach. The source of the anthropomorphic model was a clinical Magnetic Resonance Imaging (MRI) patient image set, which was segmented slice by slice into adipose and glandular tissues, skin and tumour formations; thus obtaining a four component computational breast model. The segmented tissues were mapped to specific Hounsfield Units (HU) values, which were derived from clinical breast Computed Tomography (CT) data. The obtained computational model was used as a template for producing a physical anthropomorphic breast phantom using 3D printing. FDM technology with only one polylactic acid filament was used. The physical breast phantom was scanned at Siemens SOMATOM Definition CT. Quantitative and qualitative evaluation were carried out to assess the clinical realism of CT slices of the physical breast phantom.Main results. The comparison between selected slices from the computational breast phantom and CT slices of the physical breast phantom shows similar visual x-ray appearance of the four breast tissue structures: adipose, glandular, tumour and skin. The results from the task-based evaluation, which involved three radiologists, showed a high degree of realistic clinical radiological appearance of the modelled breast components. Measured HU values of the printed structures are within the range of HU values used in the computational phantom. Moreover, measured physical parameters of the breast phantom, such as weight and linear dimensions, agreed very well with the corresponding ones of the computational breast model.Significance. The presented approach, based on a single FDM material, was found suitable for manufacturing of a physical breast phantom, which mimics well the 3D spatial distribution of the different breast tissues and their x-ray absorption properties. As such, it could be successfully exploited in advanced x-ray breast imaging research applications.
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Affiliation(s)
- Nikolay Dukov
- Department of Medical Equipment, Electronic and Information Technologies in Healthcare, Medical University of Varna, Varna, Bulgaria
| | - Kristina Bliznakova
- Department of Medical Equipment, Electronic and Information Technologies in Healthcare, Medical University of Varna, Varna, Bulgaria
| | | | - Tsvetelina Teneva
- Department of Imaging Diagnostics, Interventional Radiology and Radiotherapy, Medical University of Varna, Bulgaria
| | - Elitsa Encheva
- Department of Imaging Diagnostics, Interventional Radiology and Radiotherapy, Medical University of Varna, Bulgaria
| | - Zhivko Bliznakov
- Department of Medical Equipment, Electronic and Information Technologies in Healthcare, Medical University of Varna, Varna, Bulgaria
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Huynh E, Boyle S, Campbell J, Penney J, Mak RH, Schoenfeld JD, Leeman JE, Williams CL. Technical Note: Toward implementation of MR-guided radiation therapy for Laryngeal cancer with healthy volunteer imaging and a custom MR-CT larynx phantom. Med Phys 2022; 49:1814-1821. [PMID: 35090060 DOI: 10.1002/mp.15472] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 12/30/2021] [Accepted: 01/03/2022] [Indexed: 11/08/2022] Open
Abstract
PURPOSE Internal motion of the larynx can cause normal tissue toxicity and/or tumor underdosage during radiotherapy. MR-guided radiation therapy (MRgRT) provides improved soft-tissue contrast for patient setup, and real-time gating of radiation based on cine imaging of tumor motion, potentially making it an advantageous modality for laryngeal treatments. However, there are potential concerns regarding the small target size, proximity to heterogeneous tissue interfaces in the airway that may cause dosimetric errors in the presence of the magnetic field, and uncertainty about the ability of MR-linear accelerator (MR-Linac) systems to visualize and track laryngeal motion. To date, there have been no reports of the use of MRgRT for laryngeal treatments. METHODS A healthy volunteer was imaged on a ViewRay MRIdian MR-Linac. Organs-at-risk and a laryngeal pseudo target were contoured and used to generate a stereotactic body radiotherapy plan. A custom phantom was created using 3D-printing based on structures delineated on the volunteer images to construct an enclosure containing the target and airway anatomy, with a gap for radiochromic film, and filled with gelatin . The treatment plan was mapped onto the phantom and delivered dose assessed on radiochromic film with global normalization and a 10% dose threshold. A cine MR of the volunteer was acquired to assess the magnitude of larynx motion with speaking and swallowing, and system's ability to gate radiation. RESULTS A clinically acceptable laryngeal treatment plan and larynx phantom that was MR and CT-visible were successfully created. The delivered dose had good agreement with the treatment plan with a gamma passing rate of 96.5% (3%/2mm). The MR-Linac was able to visualize, track, and gate larynx motion. CONCLUSIONS The MRgRT workflow for laryngeal treatments was assessed and performed in preparation for clinical implementation on the MR-Linac, demonstrating that it is feasible to treat laryngeal cancer patients on the MR-Linac. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Elizabeth Huynh
- Department of Radiation Oncology, Dana-Farber Cancer Institute, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA.,Present address: London Regional Cancer Program, London Health Sciences Centre, London, ON, N6K 1C2, Canada
| | - Sara Boyle
- Department of Radiation Oncology, Dana-Farber Cancer Institute, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Jennifer Campbell
- Department of Radiation Oncology, Dana-Farber Cancer Institute, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Jessica Penney
- Department of Radiation Oncology, Dana-Farber Cancer Institute, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Raymond H Mak
- Department of Radiation Oncology, Dana-Farber Cancer Institute, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Jonathan D Schoenfeld
- Department of Radiation Oncology, Dana-Farber Cancer Institute, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Jonathan E Leeman
- Department of Radiation Oncology, Dana-Farber Cancer Institute, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Christopher L Williams
- Department of Radiation Oncology, Dana-Farber Cancer Institute, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
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Badiuk SR, Sasaki DK, Rickey DW. An anthropomorphic maxillofacial phantom using 3-dimensional printing, polyurethane rubber and epoxy resin for dental imaging and dosimetry. Dentomaxillofac Radiol 2022; 51:20200323. [PMID: 34133225 PMCID: PMC8693332 DOI: 10.1259/dmfr.20200323] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
OBJECTIVE The aim of this study was to construct an anthropomorphic maxillofacial phantom for dental imaging and dosimetry purposes using three-dimensional (3D) printing technology and materials that simulate the radiographic properties of tissues. METHODS Stereolithography photoreactive resins, polyurethane rubber and epoxy resin were modified by adding calcium carbonate and strontium carbonate powders or glass bubbles. These additives were used to change the materials' CT numbers to mimic various body tissues. A maxillofacial phantom was designed using CT images of a head. RESULTS Commercial 3D printing resins were found to have CT numbers near 120 HU and were used to print intervertebral discs and an external skin for the maxillofacial phantom. By adding various amounts of calcium carbonate and strontium carbonate powders the CT number of the resin was raised to 1000 & 1500 HU and used to print bone mimics. Epoxy resin modified by adding glass bubbles was used in assembly and as a cartilaginous mimic. Glass bubbles were added to polyurethane rubber to reduce the CT number to simulate soft tissue and filled spaces between the printed anatomy and external skin of the phantom. CONCLUSION The maxillofacial phantom designed for dental imaging and dosimetry constructed using 3D printing, polyurethane rubbers and epoxy resins represented a patient anatomically and radiographically. The results of the designed phantom, materials and assembly process can be applied to generate different phantoms that better represent diverse patient types and accommodate different ion chambers.
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Affiliation(s)
- Sawyer Rhae Badiuk
- Department of Physics and Astronomy, University of Manitoba, Winnipeg, Canada
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Mei K, Geagan M, Roshkovan L, Litt HI, Gang GJ, Shapira N, Stayman JW, Noël PB. Three-dimensional printing of patient-specific lung phantoms for CT imaging: Emulating lung tissue with accurate attenuation profiles and textures. Med Phys 2021; 49:825-835. [PMID: 34910309 DOI: 10.1002/mp.15407] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Revised: 11/22/2021] [Accepted: 11/22/2021] [Indexed: 11/10/2022] Open
Abstract
PURPOSE Phantoms are a basic tool for assessing and verifying performance in CT research and clinical practice. Patient-based realistic lung phantoms accurately representing textures and densities are essential in developing and evaluating novel CT hardware and software. This study introduces PixelPrint, a 3D printing solution to create patient-based lung phantoms with accurate attenuation profiles and textures. METHODS PixelPrint, a software tool, was developed to convert patient digital imaging and communications in medicine (DICOM) images directly into FDM printer instructions (G-code). Density was modeled as the ratio of filament to voxel volume to emulate attenuation profiles for each voxel, with the filament ratio controlled through continuous modification of the printing speed. A calibration phantom was designed to determine the mapping between filament line width and Hounsfield units (HU) within the range of human lungs. For evaluation of PixelPrint, a phantom based on a single human lung slice was manufactured and scanned with the same CT scanner and protocol used for the patient scan. Density and geometrical accuracy between phantom and patient CT data were evaluated for various anatomical features in the lung. RESULTS For the calibration phantom, measured mean HU show a very high level of linear correlation with respect to the utilized filament line widths, (r > 0.999). Qualitatively, the CT image of the patient-based phantom closely resembles the original CT image both in texture and contrast levels (from -800 to 0 HU), with clearly visible vascular and parenchymal structures. Regions of interest comparing attenuation illustrated differences below 15 HU. Manual size measurements performed by an experienced thoracic radiologist reveal a high degree of geometrical correlation of details between identical patient and phantom features, with differences smaller than the intrinsic spatial resolution of the scans. CONCLUSION The present study demonstrates the feasibility of 3D-printed patient-based lung phantoms with accurate organ geometry, image texture, and attenuation profiles. PixelPrint will enable applications in the research and development of CT technology, including further development in radiomics.
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Affiliation(s)
- Kai Mei
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Michael Geagan
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Leonid Roshkovan
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Harold I Litt
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Grace J Gang
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, USA
| | - Nadav Shapira
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - J Webster Stayman
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, USA
| | - Peter B Noël
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Department of Diagnostic and Interventional Radiology, School of Medicine & Klinikum rechts der Isar, Technical University of Munich, München, Germany
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45
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Giacometti V, King RB, McCreery C, Buchanan F, Jeevanandam P, Jain S, Hounsell AR, McGarry CK. 3D-printed patient-specific pelvis phantom for dosimetry measurements for prostate stereotactic radiotherapy with dominant intraprostatic lesion boost. Phys Med 2021; 92:8-14. [PMID: 34823110 DOI: 10.1016/j.ejmp.2021.10.018] [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: 07/01/2021] [Revised: 09/29/2021] [Accepted: 10/30/2021] [Indexed: 10/19/2022] Open
Abstract
AIM Developing and assessing the feasibility of using a three-dimensional (3D) printed patient-specific anthropomorphic pelvis phantom for dose calculation and verification for stereotactic ablative radiation therapy (SABR) with dose escalation to the dominant intraprostatic lesions. MATERIAL AND METHODS A 3D-printed pelvis phantom, including bone-mimicking material, was fabricated based on the computed tomography (CT) images of a prostate cancer patient. To compare the extent to which patient and phantom body and bones overlapped, the similarity Dice coefficient was calculated. Modular cylindrical inserts were created to encapsulate radiochromic films and ionization chamber for absolute dosimetry measurements at the location of prostate and at the boost region. Gamma analysis evaluation with 2%/2mm criteria was performed to compare treatment planning system calculations and measured dose when delivering a 10 flattening filter free (FFF) SABR plan and a 10FFF boost SABR plan. RESULTS Dice coefficients of 0.98 and 0.91 were measured for body and bones, respectively, demonstrating agreement between patient and phantom outlines. For the boost plans the gamma analysis yielded 97.0% of pixels passing 2%/2mm criteria and these results were supported by the chamber average dose difference of 0.47 ± 0.03%. These results were further improved when overriding the bone relative electron density: 97.3% for the 2%/2mm gamma analysis, and 0.05 ± 0.03% for the ionization chamber average dose difference. CONCLUSIONS The modular patient-specific 3D-printed pelvis phantom has proven to be a highly attractive and versatile tool to validate prostate SABR boost plans using multiple detectors.
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Affiliation(s)
- Valentina Giacometti
- Patrick G. Johnston Centre for Cancer Research, Queen's University, Belfast, United Kingdom.
| | - Raymond B King
- Northern Ireland Cancer Centre, Belfast Health and Social Care Trust, Belfast, United Kingdom
| | - Craig McCreery
- School of Mechanical & Aerospace Engineering, Queen's University, Belfast, United Kingdom
| | - Fraser Buchanan
- School of Mechanical & Aerospace Engineering, Queen's University, Belfast, United Kingdom
| | - Prakash Jeevanandam
- Northern Ireland Cancer Centre, Belfast Health and Social Care Trust, Belfast, United Kingdom
| | - Suneil Jain
- Patrick G. Johnston Centre for Cancer Research, Queen's University, Belfast, United Kingdom; Northern Ireland Cancer Centre, Belfast Health and Social Care Trust, Belfast, United Kingdom
| | - Alan R Hounsell
- Patrick G. Johnston Centre for Cancer Research, Queen's University, Belfast, United Kingdom; Northern Ireland Cancer Centre, Belfast Health and Social Care Trust, Belfast, United Kingdom
| | - Conor K McGarry
- Patrick G. Johnston Centre for Cancer Research, Queen's University, Belfast, United Kingdom; Northern Ireland Cancer Centre, Belfast Health and Social Care Trust, Belfast, United Kingdom
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Halloran A, Newhauser W, Chu C, Donahue W. Personalized 3D-printed anthropomorphic phantoms for dosimetry in charged particle fields. Phys Med Biol 2021; 66. [PMID: 34654002 DOI: 10.1088/1361-6560/ac3047] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Accepted: 10/15/2021] [Indexed: 11/11/2022]
Abstract
Anthropomorphic phantoms used for radiation dose measurements are designed to mimic human tissue in shape, size, and tissue composition. Reference phantoms are widely available and are sufficiently similar to many, but not all, human subjects. 3D printing has the potential to overcome some of these shortcomings by enabling rapid fabrication of personalized phantoms for individual human subjects based on radiographic imaging data.Objective. The objective of this study was to test the efficacy of personalized 3D printed phantoms for charged particle therapy. To accomplish this, we measured dose distributions from 6 to 20 MeV electron beams, incident on printed and molded slices of phantoms.Approach. Specifically, we determined the radiological properties of 3D printed phantoms, including beam penetration range. Additionally, we designed and printed a personalized head phantom to compare results obtained with a commercial, reference head phantom for quality assurance of therapeutic electron beam dose calculations.Main Results. For regions of soft tissue, gamma index analyses revealed a 3D printed slice was able to adequately model the same electron beam penetration ranges as the molded reference slice. The printed, personalized phantom provided superior dosimetric accuracy compared to the molded reference phantom for electron beam dose calculations at all electron beam energies. However, current limitations in the ability to print high-density structures, such as bone, limited pass rates of 60% or better at 16 and 20 MeV electron beam energies.Significance. This study showed that creating personalized phantoms using 3D printing techniques is a feasible way to substantially improve the accuracy of dose measurements of therapeutic electron beams, but further improvements in printing techniques are necessary in order to increase the printable density in phantoms.
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Affiliation(s)
- Andrew Halloran
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana, United States of America
| | - Wayne Newhauser
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana, United States of America.,Department of Radiation Physics, Mary Bird Perkins Cancer Center, Baton Rouge, Louisiana, United States of America
| | - Connel Chu
- Department of Radiation Physics, Mary Bird Perkins Cancer Center, Baton Rouge, Louisiana, United States of America
| | - William Donahue
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana, United States of America
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Tino RB, Yeo AU, Brandt M, Leary M, Kron T. A customizable anthropomorphic phantom for dosimetric verification of 3D-printed lung, tissue, and bone density materials. Med Phys 2021; 49:52-69. [PMID: 34796527 DOI: 10.1002/mp.15364] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 08/26/2021] [Accepted: 10/30/2021] [Indexed: 12/29/2022] Open
Abstract
PURPOSE To design and manufacture a customized thoracic phantom slab utilizing the 3D printing process, also known as additive manufacturing, consisting of different tissue density materials. Here, we demonstrate the 3D-printed phantom's clinical feasibility for imaging and dosimetric verification of volumetric modulated arc radiotherapy (VMAT) plans for lung and spine stereotactic ablative body radiotherapy (SABR) through end-to-end dosimetric verification. METHODS A customizable anthropomorphic phantom slab was designed using the CT dataset of a commercial phantom (adult female ATOM dosimetry phantom, CIRS Inc.). Material extrusion 3D printing was utilized to manufacture the phantom slab consisting of acrylonitrile butadiene styrene material for the lung and the associated lesion, polylactic acid (PLA) material for soft tissue and spinal cord, and both PLA and iron-reinforced PLA materials for bone. CT images were acquired for both the commercial phantom and 3D-printed phantom for HU comparison. VMAT plans were generated for spine and lung SABR scenarios and were delivered as per departmental SABR protocols using a Varian TrueBeam STx linear accelerator. End-to-end dosimetry was implemented with radiochromic films, analyzed with gamma criteria of 5% dose difference, and a distance-to-agreement of 1 mm, at a 10% low-dose threshold by comparing with calculated dose using the Acuros algorithm of the Eclipse treatment planning system (v15.6). RESULTS 3D-printed phantom inserts were observed to produce HU ranging from -750 to 2100. The 3D-printed phantom slab was observed to achieve a similar range of HU from the commercial phantom including a mean HU of -760 for lung tissue, a mean HU of 50 for soft tissue, and a mean HU of 220 and 630 for low- and high-density bone, respectively. Film dosimetry results show 2D-gamma passing rates for lung SABR (internal and superior) and spine SABR (inferior and superior) over 98% and 90%, respectively. CONCLUSIONS The end-to-end testing of VMAT plans for spine and lung SABR suggests the clinical feasibility of the 3D-printed phantom, consisting of different tissue density materials that emulate lung, soft tissue, and bone in kV imaging and megavoltage photon dosimetry. Further investigation of the proposed 3D printing techniques for manufacturability and reproducibility will enable the development of clinical 3D-printed phantoms in radiotherapy.
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Affiliation(s)
- Rance Bolislis Tino
- RMIT Centre for Additive Manufacturing, School of Engineering, RMIT University, Melbourne, Victoria, Australia.,Department of Physical Sciences, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia.,ARC Industrial Transformation Training Centre in Additive Biomanufacturing, Queensland University of Technology, Queensland, Brisbane, Australia
| | - Adam Unjin Yeo
- School of Applied Sciences, RMIT University, Melbourne, Victoria, Australia.,Department of Physical Sciences, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia
| | - Milan Brandt
- RMIT Centre for Additive Manufacturing, School of Engineering, RMIT University, Melbourne, Victoria, Australia.,ARC Industrial Transformation Training Centre in Additive Biomanufacturing, Queensland University of Technology, Queensland, Brisbane, Australia
| | - Martin Leary
- RMIT Centre for Additive Manufacturing, School of Engineering, RMIT University, Melbourne, Victoria, Australia.,ARC Industrial Transformation Training Centre in Additive Biomanufacturing, Queensland University of Technology, Queensland, Brisbane, Australia
| | - Tomas Kron
- Department of Physical Sciences, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia.,Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Victoria, Australia.,ARC Industrial Transformation Training Centre in Additive Biomanufacturing, Queensland University of Technology, Queensland, Brisbane, Australia.,Centre for Medical Radiation Physics, University of Wollongong, Wollongong, New South Wales, Australia
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Tajik M, Akhlaqi MM, Gholami S. Advances in anthropomorphic thorax phantoms for radiotherapy: a review. Biomed Phys Eng Express 2021; 8. [PMID: 34736235 DOI: 10.1088/2057-1976/ac369c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Accepted: 11/04/2021] [Indexed: 11/12/2022]
Abstract
A phantom is a highly specialized device, which mimic human body, or a part of it. There are three categories of phantoms: physical phantoms, physiological phantoms, and computational phantoms. The phantoms have been utilized in medical imaging and radiotherapy for numerous applications. In radiotherapy, the phantoms may be used for various applications such as quality assurance (QA), dosimetry, end-to-end testing, etc. In thoracic radiotherapy, unique QA problems including tumor motion, thorax deformation, and heterogeneities in the beam path have complicated the delivery of dose to both tumor and organ at risks (OARs). Also, respiratory motion is a major challenge in radiotherapy of thoracic malignancies, which can be resulted in the discrepancies between the planned and delivered doses to cancerous tissue. Hence, the overall treatment procedure needs to be verified. Anthropomorphic thorax phantoms, which are made of human tissue-mimicking materials, can be utilized to obtain the ground truth to validate these processes. Accordingly, research into new anthropomorphic thorax phantoms has accelerated. Therefore, the review is intended to summarize the current status of the commercially available and in-house-built anthropomorphic physical/physiological thorax phantoms in radiotherapy. The main focus is on anthropomorphic, deformable thorax motion phantoms. This review also discusses the applications of three-dimensional (3D) printing technology for the fabrication of thorax phantoms.
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Affiliation(s)
- Mahdieh Tajik
- Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Iran Tehran district 6 poursina st Tehran University of Medical Sciences, Tehran, 1416753955, Iran (the Islamic Republic of)
| | - Mohammad Mohsen Akhlaqi
- Shahid Beheshti University of Medical Sciences, Iran,Tehran,Shahid Bahonar roundabout, Darabad Avenue,Masih Daneshvari Hospital, Tehran, 19839-63113, Iran (the Islamic Republic of)
| | - Somayeh Gholami
- Radiotherapy, Tehran University of Medical Sciences, Bolvarekeshavarz AVN, Tehran, Iran, Tehran, 1416753955, Iran (the Islamic Republic of)
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Abd. Rahni AA, Mustaza SM, Mokri SS, Azmi NA, Ahmad R, Ramli R, Wan Abdul Rahman WN. Design of a 3D Printed Respiratory Motion Thoracic Phantom. 2021 IEEE NUCLEAR SCIENCE SYMPOSIUM AND MEDICAL IMAGING CONFERENCE (NSS/MIC) 2021. [DOI: 10.1109/nss/mic44867.2021.9875875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
Affiliation(s)
| | | | | | | | - R. Ahmad
- Universiti Kebangsaan Malaysia,Malaysia
| | - R. Ramli
- Universiti Kebangsaan Malaysia,Malaysia
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McCallum S, Maresse S, Fearns P. Evaluating 3D-printed Bolus Compared to Conventional Bolus Types Used in External Beam Radiation Therapy. Curr Med Imaging 2021; 17:820-831. [PMID: 33530912 DOI: 10.2174/1573405617666210202114336] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Revised: 12/05/2020] [Accepted: 12/08/2020] [Indexed: 11/22/2022]
Abstract
BACKGROUND When treating superficial tumors with external beam radiation therapy, bolus is often used. Bolus increases surface dose, reduces dose to underlying tissue, and improves dose homogeneity. INTRODUCTION The conventional bolus types used clinically in practice have some disadvantages. The use of Three-Dimensional (3D) printing has the potential to create more effective boluses. CT data is used for dosimetric calculations for these treatments and often to manufacture the customized 3D-printed bolus. PURPOSE The aim of this review is to evaluate the published studies that have compared 3D-printed bolus against conventional bolus types. METHODS AND RESULTS A systematic search of several databases and a further appraisal for relevance and eligibility resulted in the 14 articles used in this review. The 14 articles were analyzed based on their comparison of 3D-printed bolus and at least one conventional bolus type. CONCLUSION The findings of this review indicated that 3D-printed bolus has a number of advantages. Compared to conventional bolus types, 3D-printed bolus was found to have equivalent or improved dosimetric measures, positional accuracy, fit, and uniformity. 3D-printed bolus was also found to benefit workflow efficiency through both time and cost effectiveness. However, factors such as patient comfort and staff perspectives need to be further explored to support the use of 3Dprinted bolus in routine practice.
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Affiliation(s)
- Stephanie McCallum
- Medical Radiation Science, Faculty of Science and Engineering, Curtin University, Perth, Australia
| | - Sharon Maresse
- Medical Radiation Science, Faculty of Science and Engineering, Curtin University, Perth, Australia
| | - Peter Fearns
- Medical Radiation Science, Faculty of Science and Engineering, Curtin University, Perth, Australia
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