1
|
Bento M, Cook H, Anaya VM, Bär E, Nisbet A, Lourenço A, Hussein M, Veiga C. Characterisation of 3D-printable thermoplastics to be used as tissue-equivalent materials in photon and proton beam radiotherapy end-to-end quality assurance devices. Biomed Phys Eng Express 2024; 10:065005. [PMID: 39145621 DOI: 10.1088/2057-1976/ad6f95] [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: 06/10/2024] [Accepted: 08/13/2024] [Indexed: 08/16/2024]
Abstract
Objective.To investigate the potential of 3D-printable thermoplastics as tissue-equivalent materials to be used in multimodal radiotherapy end-to-end quality assurance (QA) devices.Approach.Six thermoplastics were investigated: Polylactic Acid (PLA), Acrylonitrile Butadiene Styrene (ABS), Polyethylene Terephthalate Glycol (PETG), Polymethyl Methacrylate (PMMA), High Impact Polystyrene (HIPS) and StoneFil. Measurements of mass density (ρ), Relative Electron Density (RED), in a nominal 6 MV photon beam, and Relative Stopping Power (RSP), in a 210 MeV proton pencil-beam, were performed. Average Hounsfield Units (HU) were derived from CTs acquired with two independent scanners. The calibration curves of both scanners were used to predict averageρ,RED and RSP values and compared against the experimental data. Finally, measured data ofρ,RED and RSP was compared against theoretical values estimated for the thermoplastic materials and biological tissues.Main results.Overall, goodρand RSP CT predictions were made; only PMMA and PETG showed differences >5%. The differences between experimental and CT predicted RED values were also <5% for PLA, ABS, PETG and PMMA; for HIPS and StoneFil higher differences were found (6.94% and 9.42/15.34%, respectively). Small HU variations were obtained in the CTs for all materials indicating good uniform density distribution in the samples production. ABS, PLA, PETG and PMMA showed potential equivalency for a variety of soft tissues (adipose tissue, skeletal muscle, brain and lung tissues, differences within 0.19%-8.35% for all properties). StoneFil was the closest substitute to bone, but differences were >10%. Theoretical calculations of all properties agreed with experimental values within 5% difference for most thermoplastics.Significance.Several 3D-printed thermoplastics were promising tissue-equivalent materials to be used in devices for end-to-end multimodal radiotherapy QA and may not require corrections in treatment planning systems' dose calculations. Theoretical calculations showed promise in identifying thermoplastics matching target biological tissues before experiments are performed.
Collapse
Affiliation(s)
- Mariana Bento
- Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
- Radiotherapy and Radiation Dosimetry Group, National Physical Laboratory, Teddington, United Kingdom
| | - Hannah Cook
- Radiotherapy and Radiation Dosimetry Group, National Physical Laboratory, Teddington, United Kingdom
| | - Virginia Marin Anaya
- Radiotherapy Physics Services, University College London Hospitals NHS Foundation Trust, London, United Kingdom
| | - Esther Bär
- Radiotherapy Physics Services, University College London Hospitals NHS Foundation Trust, London, United Kingdom
| | - Andrew Nisbet
- Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | - Ana Lourenço
- Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
- Radiotherapy and Radiation Dosimetry Group, National Physical Laboratory, Teddington, United Kingdom
| | - Mohammad Hussein
- Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
- Radiotherapy and Radiation Dosimetry Group, National Physical Laboratory, Teddington, United Kingdom
| | - Catarina Veiga
- Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| |
Collapse
|
2
|
Ashraf MR, Melemenidis S, Liu K, Grilj V, Jansen J, Velasquez B, Connell L, Schulz JB, Bailat C, Libed A, Manjappa R, Dutt S, Soto L, Lau B, Garza A, Larsen W, Skinner L, Yu AS, Surucu M, Graves EE, Maxim PG, Kry SF, Vozenin MC, Schüler E, Loo BW. Multi-Institutional Audit of FLASH and Conventional Dosimetry With a 3D Printed Anatomically Realistic Mouse Phantom. Int J Radiat Oncol Biol Phys 2024; 120:287-300. [PMID: 38493902 DOI: 10.1016/j.ijrobp.2024.03.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 03/03/2024] [Accepted: 03/10/2024] [Indexed: 03/19/2024]
Abstract
PURPOSE We conducted a multi-institutional dosimetric audit between FLASH and conventional dose rate (CONV) electron irradiations by using an anatomically realistic 3-dimensional (3D) printed mouse phantom. METHODS AND MATERIALS A computed tomography (CT) scan of a live mouse was used to create a 3D model of bony anatomy, lungs, and soft tissue. A dual-nozzle 3D printer was used to print the mouse phantom using acrylonitrile butadiene styrene (∼1.02 g/cm3) and polylactic acid (∼1.24 g/cm3) simultaneously to simulate soft tissue and bone densities, respectively. The lungs were printed separately using lightweight polylactic acid (∼0.64 g/cm3). Hounsfield units (HU), densities, and print-to-print stability of the phantoms were assessed. Three institutions were each provided a phantom and each institution performed 2 replicates of irradiations at selected anatomic regions. The average dose difference between FLASH and CONV dose distributions and deviation from the prescribed dose were measured with radiochromic film. RESULTS Compared with the reference CT scan, CT scans of the phantom demonstrated mass density differences of 0.10 g/cm3 for bone, 0.12 g/cm3 for lung, and 0.03 g/cm3 for soft tissue regions. Differences in HU between phantoms were <10 HU for soft tissue and bone, with lung showing the most variation (54 HU), but with minimal effect on dose distribution (<0.5%). Mean differences between FLASH and CONV decreased from the first to the second replicate (4.3%-1.2%), and differences from the prescribed dose decreased for both CONV (3.6%-2.5%) and FLASH (6.4%-2.7%). Total dose accuracy suggests consistent pulse dose and pulse number, although these were not specifically assessed. Positioning variability was observed, likely due to the absence of robust positioning aids or image guidance. CONCLUSIONS This study marks the first dosimetric audit for FLASH using a nonhomogeneous phantom, challenging conventional calibration practices reliant on homogeneous phantoms. The comparison protocol offers a framework for credentialing multi-institutional studies in FLASH preclinical research to enhance reproducibility of biologic findings.
Collapse
Affiliation(s)
- M Ramish Ashraf
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Stavros Melemenidis
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Kevin Liu
- Department of Radiation Physics, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Veljko Grilj
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Jeannette Jansen
- Radiation Oncology Laboratory, Department of Radiation Oncology, Lausanne, University Hospital and University of Lausanne, Switzerland
| | - Brett Velasquez
- Department of Radiation Physics, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Luke Connell
- Department of Radiation Physics, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Joseph B Schulz
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Claude Bailat
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Aaron Libed
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Rakesh Manjappa
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Suparna Dutt
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Luis Soto
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Brianna Lau
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Aaron Garza
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - William Larsen
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Lawrie Skinner
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Amy S Yu
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Murat Surucu
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Edward E Graves
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California; Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California
| | - Peter G Maxim
- Department of Radiation Oncology, University of California, Irvine, California
| | - Stephen F Kry
- Department of Radiation Physics, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas; Imaging and Radiation Oncology Core, MD Anderson Cancer Center, Houston, USA
| | - Marie-Catherine Vozenin
- Radiation Oncology Laboratory, Department of Radiation Oncology, Lausanne, University Hospital and University of Lausanne, Switzerland; Radiotherapy and Radiobiology Sector, Radiation Therapy Service, University Hospital of Geneva, Geneva, Switzerland.
| | - Emil Schüler
- Department of Radiation Physics, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
| | - Billy W Loo
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California; Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California.
| |
Collapse
|
3
|
Bustillo JPO, Posadas JRD, Mata JL, Inocencio ET, Rosenfeld AB, Lerch MLF. 3D printed heterogeneous paediatric head and adult thorax phantoms for linear accelerator radiotherapy quality assurance: from fabrication to treatment delivery. Biomed Phys Eng Express 2024; 10:055037. [PMID: 39142300 DOI: 10.1088/2057-1976/ad6f13] [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: 05/08/2024] [Accepted: 08/14/2024] [Indexed: 08/16/2024]
Abstract
Objective. This study aims to design and fabricate a 3D printed heterogeneous paediatric head phantom and to customize a thorax phantom for radiotherapy dosimetry.Approach. This study designed, fabricated, and tested 3D printed radiotherapy phantoms that can simulate soft tissue, lung, brain, and bone. Various polymers were considered in designing the phantoms. Polylactic acid+, nylon, and plaster were used in simulating different tissue equivalence. Dimensional accuracy, and CT number were investigated. The phantoms were subjected to a complete radiotherapy clinical workflow. Several treatment plans were delivered in both the head and the thorax phantom from a simple single 6 MV beam, parallel opposed beams, and five-field intensity modulated radiotherapy (IMRT) beams. Dose measurements using an ionization chamber and radiochromic films were compared with the calculated doses of the Varian Eclipse treatment planning system (TPS).Main results. The fabricated heterogeneous phantoms represent paediatric human head and adult thorax based on its radiation attenuation and anatomy. The measured CT number ranges are within -786.23 ± 10.55, 0.98 ± 3.86, 129.51 ± 12.83, and 651.14 ± 47.76 HU for lung, water/brain, soft tissue, and bone, respectively. It has a good radiological imaging visual similarity relative to a real human head and thorax depicting soft tissue, lung, bone, and brain. The accumulated dose readings for both conformal radiotherapy and IMRT match with the TPS calculated dose within ±2% and ±4% for head and thorax phantom, respectively. The mean pass rate for all the plans delivered are above 90% for gamma analysis criterion of 3%/3 mm.Significance and conclusion. The fabricated heterogeneous paediatric head and thorax phantoms are useful in Linac end-to-end radiotherapy quality assurance based on its CT image and measured radiation dose. The manufacturing and dosimetry workflow of this study can be utilized by other institutions for dosimetry and trainings.
Collapse
Affiliation(s)
- John Paul O Bustillo
- Centre 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, 1000, Metro Manila, Philippines
| | - Julia Rebecca D Posadas
- Department of Physical Sciences and Mathematics, College of Arts and Sciences, University of the Philippines Manila, 1000, Metro Manila, Philippines
- Department of Radiology, University of the Philippines- Philippine General Hospital, 1000, Metro Manila, Philippines
| | - Jacob L Mata
- Department of Radiology, University of the Philippines- Philippine General Hospital, 1000, Metro Manila, Philippines
| | - Elrick T Inocencio
- Department of Physical Sciences and Mathematics, College of Arts and Sciences, University of the Philippines Manila, 1000, Metro Manila, Philippines
- Department of Radiology, University of the Philippines- Philippine General Hospital, 1000, Metro Manila, Philippines
| | - Anatoly B Rosenfeld
- Centre for Medical Radiation Physics, University of Wollongong Australia, Wollongong, NSW, 2522, Australia
| | - Michael L F Lerch
- Centre for Medical Radiation Physics, University of Wollongong Australia, Wollongong, NSW, 2522, Australia
| |
Collapse
|
4
|
Wang W, Emrich J, Mourtada F. Novel 3D printed universal conical holder for eye plaque quality assurance. J Appl Clin Med Phys 2024; 25:e14395. [PMID: 38742823 PMCID: PMC11302816 DOI: 10.1002/acm2.14395] [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: 03/11/2024] [Revised: 03/31/2024] [Accepted: 04/18/2024] [Indexed: 05/16/2024] Open
Abstract
PURPOSE For the custom-built construction of eye plaques, the iodine (I-125) seeds of different source strengths are recycled in our eye plaque program. To return I-125 seeds to the correct lot, we developed a novel 3D-printed conical plaque QA holder for relative assay for eye plaques. MATERIALS AND METHODS A universal 3D-printed conical plaque holder was designed to accommodate six plaque sizes and fit reproducibly in a well-type dose calibrator. A reproducibility test was used to compare the plaque placement consistency in the holder versus without the holder. Plaque assays were performed for assembled plaques both before implant and after explant. The explant reading was compared with the implant reading adjusted for decay, and the relative error was calculated. The plaque response fraction (PRF) is defined as the fraction of well chamber implant reading over the total seed strength for a plaque. The PRF was aggregated for each individual plaque to confirm the seed lot before implant. RESULTS The reproducibility test showed the chamber reading's relative standard deviation of 0.40% with the QA holder compared to 0.68% without it. The batch relative assay was performed for 251 plaques. The absolute value of measurement deviation between explant and decay-corrected implant readings is 0.89% ± 0.86% (mean ± standard deviation). The PRFs for individual plaques range from 36.49% to 49.87%, with a maximum standard deviation of 2%. CONCLUSIONS This novel 3D-printed QA holder provides reproducible setup for assaying assembled eye plaques in a well chamber. Batch relative assay can validate the seed batch used and plaque integrity during the implant without assaying individual seeds, saving valuable physicist time and radiation exposure from seed handling.
Collapse
Affiliation(s)
- Wentao Wang
- Thomas Jefferson UniversityPhiladelphiaPennsylvaniaUSA
| | | | | |
Collapse
|
5
|
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.
Collapse
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
| |
Collapse
|
6
|
Zhao W, Zhan Y, Li W, Hao S, Amirfazli A. Application of 3D printing for fabrication of superhydrophobic surfaces with reversible wettability. RSC Adv 2024; 14:17684-17695. [PMID: 38832241 PMCID: PMC11145027 DOI: 10.1039/d4ra02742f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Accepted: 05/27/2024] [Indexed: 06/05/2024] Open
Abstract
Control of surface wettability is needed in many applications. The potential use of 3D printing technology to gain control over wettability remains largely unexplored. In this paper, Fused Deposition Molding (FDM) 3D printing technology was utilized to print polylactic acid (PLA) microplate array structures to generate superhydrophobic surfaces with reversable wetting properties. This was achieved by spraying polydimethylsiloxane (PDMS) and silica (SiO2) solutions, over microplate surfaces. Anisotropic wetting properties were also achieved based on the surface structure design. Due to the shape memory properties of PLA, the morphology of the microplate arrays could be switched between the original upright shape and deformed shape. Through alternating pressing and heating treatments, the microplate arrays showed anisotropic wettability switching. The difference between the contact angle (CA) and sliding angle (SA) of water droplets on the original surface parallel to and perpendicular to the microplate array direction were ΔCA = 7° and ΔSA = 3° respectively, and those on the surface of the deformed microplate array were ΔCA = 7° and ΔSA = 21°, respectively. This process enabled reversible alteration in the wetting behavior of water droplets on the original and deformed surfaces between sliding and sticking states. PLA-based shape memory anisotropic superhydrophobic surfaces with tunable adhesion were successfully applied to rewritable platforms, micro droplet reaction platforms, and gas sensing.
Collapse
Affiliation(s)
- Wenxuan Zhao
- School of Materials Engineering, Jiangsu University of Technology Changzhou 213001 China
| | - Yanlong Zhan
- Smart Materials for Architecture Research Lab, Innovation Center of Yangtze River Delta, Zhejiang University Jiaxing 314100 China
| | - Wen Li
- School of Materials Engineering, Jiangsu University of Technology Changzhou 213001 China
| | - Saisai Hao
- School of Materials Engineering, Jiangsu University of Technology Changzhou 213001 China
| | - Alidad Amirfazli
- School of Materials Engineering, Jiangsu University of Technology Changzhou 213001 China
- Department of Mechanical Engineering, York University Toronto Canada
| |
Collapse
|
7
|
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.
Collapse
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
| |
Collapse
|
8
|
Karl AS, Steel JG, Warr GB. Regression fitting megavoltage depth dose curves to determine material relative electron density in radiotherapy. Phys Eng Sci Med 2023; 46:1387-1397. [PMID: 37733264 DOI: 10.1007/s13246-023-01306-8] [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: 01/02/2023] [Accepted: 07/19/2023] [Indexed: 09/22/2023]
Abstract
The relative electron density (RED) parameter is ubiquitous throughout radiotherapy for clinical dosimetry and treatment planning purposes as it provides a more accurate description of the relevant radiological properties over mass density alone. RED is in practice determined indirectly from calibrated CT Hounsfield Units (HU). While CT images provide useful 3D information, the spectral differences between CT and clinical LINAC beams may impact the validity of the CT-ED calibration, especially in the context of novel tissue-mimicking materials where deviations from biologically typical atomic number to atomic weight ratios 〈Z/A〉 occur and/or high-Z materials are present. A theoretical basis for determining material properties directly in a clinical beam spectrum via an electron-density equivalent pathlength (eEPL) method has been previously established. An experimental implementation of this approach is introduced whereby material-specific measured percentage depth dose curves (PDDs) are regressed to a PDD measured in a reference material (water), providing an inference of 〈Z/A〉, which when combined with the physical density provides a determination of RED. This method is validated over a range of tissue-mimicking materials and compared against the standard CT output, as well as compositional information obtained from the manufacturer's specifications. The measured PDD regression method shows consistent results against both manufacturer-provided and CT-derived values between 0.9 and 1.15 RED. Outside of this soft-tissue range a trend was observed whereby the 〈Z/A〉 determined becomes unrealistic indicating the method is no longer reporting RED alone and the assumptions around the eEPL model are constrained. Within the soft-tissue RED range of validity, the regression method provides a practical and robust characterisation for unknown materials in the clinical setting and may be used to improve on the CT derived RED where high Z material components are suspected.
Collapse
Affiliation(s)
- Anthony S Karl
- Mid North Coast Cancer Institute Coffs Harbour, Mid North Local Health District, Coffs Harbour Health Campus, Coffs Harbour, NSW, 2450, Australia.
| | - Jared G Steel
- Mid North Coast Cancer Institute Coffs Harbour, Mid North Local Health District, Coffs Harbour Health Campus, Coffs Harbour, NSW, 2450, Australia
| | - George B Warr
- Western Cancer Centre Dubbo, Dubbo Base Hospital, Western NSW Local Health District, Dubbo, NSW, 2830, Australia
| |
Collapse
|
9
|
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.
Collapse
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
| |
Collapse
|
10
|
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.
Collapse
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
| |
Collapse
|
11
|
Kunert P, Schlattl H, Trinkl S, Giussani A, Klein L, Janich M, Reichert D, Brix G. Reproduction of a conventional anthropomorphic female chest phantom by 3D-printing: Comparison of image contrasts and absorbed doses in CT. Med Phys 2023; 50:4734-4743. [PMID: 37415411 DOI: 10.1002/mp.16587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 05/10/2023] [Accepted: 06/11/2023] [Indexed: 07/08/2023] Open
Abstract
BACKGROUND The production of individualized anthropomorphic phantoms via three-dimensional (3D) printing methods offers promising possibilities to assess and optimize radiation exposures for specifically relevant patient groups (i.e., overweighed or pregnant persons) that are not adequately represented by standardized anthropomorphic phantoms. However, the equivalence of printed phantoms must be demonstrated exemplarily with respect to the resulting image contrasts and dose distributions. PURPOSE To reproduce a conventionally produced anthropomorphic phantom of a female chest and breasts and to evaluate their equivalence with respect to image contrasts and absorbed doses at the example of a computed tomography (CT) examination of the chest. METHODS In a first step, the effect of different print settings on the CT values of printed samples was systematically investigated. Subsequently, a transversal slice and breast add-ons of a conventionally produced female body phantom were reproduced using a multi-material extrusion-based printer, considering six different types of tissues (muscle, lung, adipose, and glandular breast tissue, as well as bone and cartilage). CT images of the printed and conventionally produced phantom parts were evaluated with respect to their geometric correspondence, image contrasts, and absorbed doses measured using thermoluminescent dosimeters. RESULTS CT values of printed objects are highly sensitive to the selected print settings. The soft tissues of the conventionally produced phantom could be reproduced with a good agreement. Minor differences in CT values were observed for bone and lung tissue, whereas absorbed doses to the relevant tissues were identical within the measurement uncertainties. CONCLUSION 3D-printed phantoms are with exception of minor contrast differences equivalent to their conventionally manufactured counterparts. When comparing the two production techniques, it is important to note that conventionally manufactured phantoms should not be considered as absolute benchmarks, as they also only approximate the human body in terms of its absorption, and attenuation of x-rays as well as its geometry.
Collapse
Affiliation(s)
- Patrizia Kunert
- Department of Medical and Occupational Radiation Protection, Federal Office for Radiation Protection, Oberschleißheim, Germany
| | - Helmut Schlattl
- Department of Medical and Occupational Radiation Protection, Federal Office for Radiation Protection, Oberschleißheim, Germany
| | - Sebastian Trinkl
- Department of Medical and Occupational Radiation Protection, Federal Office for Radiation Protection, Oberschleißheim, Germany
| | - Augusto Giussani
- Department of Medical and Occupational Radiation Protection, Federal Office for Radiation Protection, Oberschleißheim, Germany
| | - Lea Klein
- Department of Radiation Oncology, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Martin Janich
- Department of Radiation Oncology, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Detlef Reichert
- Department of Physics, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Gunnar Brix
- Department of Medical and Occupational Radiation Protection, Federal Office for Radiation Protection, Oberschleißheim, Germany
| |
Collapse
|
12
|
Aydin S, Yaşli M. Three-Dimensional Transperineal Ultrasound Modeled Personalized Pessary Manufacturing Using 3-Dimensional Printing Technology. UROGYNECOLOGY (PHILADELPHIA, PA.) 2023; 29:651-655. [PMID: 37348088 DOI: 10.1097/spv.0000000000001339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/24/2023]
Affiliation(s)
- Serdar Aydin
- From the Department of Obstetrics and Gynecology, Koç University Hospital
| | - Mert Yaşli
- Koç University School of Medicine, Koç University, Istanbul, Turkey
| |
Collapse
|
13
|
Fahimian BP, Liu W, Skinner L, Yu AS, Phillips T, Steers JM, DeMarco J, Fraass BA, Kamrava M. 3D printing in brachytherapy: A systematic review of gynecological applications. Brachytherapy 2023; 22:446-460. [PMID: 37024350 DOI: 10.1016/j.brachy.2023.02.002] [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: 09/09/2022] [Revised: 12/27/2022] [Accepted: 02/02/2023] [Indexed: 04/08/2023]
Abstract
PURPOSE To provide a systematic review of the applications of 3D printing in gynecological brachytherapy. METHODS Peer-reviewed articles relating to additive manufacturing (3D printing) from the 34 million plus biomedical citations in National Center for Biotechnology Information (NCBI/PubMed), and 53 million records in Web of Science (Clarivate) were queried for 3D printing applications. The results were narrowed sequentially to, (1) all literature in 3D printing with final publications prior to July 2022 (in English, and excluding books, proceedings, and reviews), and then to applications in, (2) radiotherapy, (3) brachytherapy, (4) gynecological brachytherapy. Brachytherapy applications were reviewed and grouped by disease site, with gynecological applications additionally grouped by study type, methodology, delivery modality, and device type. RESULTS From 47,541 3D printing citations, 96 publications met the inclusion criteria for brachytherapy, with gynecological clinical applications compromising the highest percentage (32%), followed by skin and surface (19%), and head and neck (9%). The distribution of delivery modalities was 58% for HDR (Ir-192), 35% for LDR (I-125), and 7% for other modalities. In gynecological brachytherapy, studies included design of patient specific applicators and templates, novel applicator designs, applicator additions, quality assurance and dosimetry devices, anthropomorphic gynecological applicators, and in-human clinical trials. Plots of year-to-year growth demonstrate a rapid nonlinear trend since 2014 due to the improving accessibility of low-cost 3D printers. Based on these publications, considerations for clinical use are provided. CONCLUSIONS 3D printing has emerged as an important clinical technology enabling customized applicator and template designs, representing a major advancement in the methodology for implantation and delivery in gynecological brachytherapy.
Collapse
Affiliation(s)
- Benjamin P Fahimian
- Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA.
| | - Wu Liu
- Department of Radiation Oncology, Stanford University, Stanford, CA
| | - Lawrie Skinner
- Department of Radiation Oncology, Stanford University, Stanford, CA
| | - Amy S Yu
- Department of Radiation Oncology, Stanford University, Stanford, CA
| | - Tiffany Phillips
- Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Jennifer M Steers
- Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - John DeMarco
- Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Benedick A Fraass
- Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Mitchell Kamrava
- Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA
| |
Collapse
|
14
|
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.
Collapse
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
| |
Collapse
|
15
|
Biltekin F, Bäumer C, Esser J, Ghanem O, Ozyigit G, Timmermann B. Preclinical Dosimetry for Small Animal Radiation Research in Proton Therapy: A Feasibility Study. Int J Part Ther 2023; 10:13-22. [PMID: 37823014 PMCID: PMC10563666 DOI: 10.14338/ijpt-22-00035.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 02/10/2023] [Indexed: 10/13/2023] Open
Abstract
Purpose To evaluate the feasibility of the three-dimensional (3D) printed small animal phantoms in dosimetric verification of proton therapy for small animal radiation research. Materials and Methods Two different phantoms were modeled using the computed-tomography dataset of real rat and tumor-bearing mouse, retrospectively. Rat phantoms were designed to accommodate both EBT3 film and ionization chamber. A subcutaneous tumor-bearing mouse phantom was only modified to accommodate film dosimetry. All phantoms were printed using polylactic-acid (PLA) filament. Optimal printing parameters were set to create tissue-equivalent material. Then, proton therapy plans for different anatomical targets, including whole brain and total lung irradiation in the rat phantom and the subcutaneous tumor model in the mouse phantom, were created using the pencil-beam scanning technique. Point dose and film dosimetry measurements were performed using 3D-printed phantoms. In addition, all phantoms were analyzed in terms of printing accuracy and uniformity. Results Three-dimensionally printed phantoms had excellent uniformity over the external body, and printing accuracy was within 0.5 mm. According to our findings, two-dimensional dosimetry with EBT3 showed acceptable levels of γ passing rate for all measurements except for whole brain irradiation (γ passing rate, 89.8%). In terms of point dose analysis, a good agreement (<0.1%) was found between the measured and calculated point doses for all anatomical targets. Conclusion Three-dimensionally printed small animal phantoms show great potential for dosimetric verifications of clinical proton therapy for small animal radiation research.
Collapse
Affiliation(s)
- Fatih Biltekin
- Department of Radiation Oncology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
- West German Proton Therapy Centre Essen (WPE), Essen, Germany
| | - Christian Bäumer
- West German Proton Therapy Centre Essen (WPE), Essen, Germany
- West German Cancer Centre (WTZ), Essen, Germany
- German Cancer Consortium (DKTK), Heidelberg, Germany
- TU Dortmund University, Department of Physics, Dortmund, Germany
| | - Johannes Esser
- West German Proton Therapy Centre Essen (WPE), Essen, Germany
- West German Cancer Centre (WTZ), Essen, Germany
| | - Osamah Ghanem
- West German Proton Therapy Centre Essen (WPE), Essen, Germany
- West German Cancer Centre (WTZ), Essen, Germany
| | - Gokhan Ozyigit
- Department of Radiation Oncology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Beate Timmermann
- West German Proton Therapy Centre Essen (WPE), Essen, Germany
- West German Cancer Centre (WTZ), Essen, Germany
- German Cancer Consortium (DKTK), Heidelberg, Germany
- TU Dortmund University, Department of Physics, Dortmund, Germany
- Department of Particle Therapy, University Hospital Essen, Essen, Germany
| |
Collapse
|
16
|
Fonseca GP, Rezaeifar B, Lackner N, Haanen B, Reniers B, Verhaegen F. Dual-energy CT evaluation of 3D printed materials for radiotherapy applications. Phys Med Biol 2023; 68. [PMID: 36584391 DOI: 10.1088/1361-6560/acaf4a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 12/30/2022] [Indexed: 12/31/2022]
Abstract
Objective. There is a continuous increase in 3D printing applications in several fields including medical imaging and radiotherapy. Although there are numerous advantages of using 3D printing for the development of customized phantoms, bolus, quality assurance devices and other clinical applications, material properties are not well known and printer settings can affect considerably the properties (e.g. density, isotropy and homogeneity) of the printed parts. This study aims to evaluate several materials and printer properties to identify a range of tissue-mimicking materials.Approach. Dual-energy CT was used to obtain the effective atomic number (Zeff) and relative electron density (RED) for thirty-one different materials including different colours of the same filament from the same manufacturer and the same type of filament from different manufacturers. In addition, a custom bone equivalent filament was developed and evaluated since a high-density filament with a composition similar to bone is not commercially available. Printing settings such as infill density, infill pattern, layer height and nozzle size were also evaluated.Main results. Large differences were observed for HU (288), RED (>10%) andZeff(>50%) for different colours of the same filament due to the colour pigment. Results show a wide HU variation (-714 to 1104), RED (0.277 to 1.480) andZeff(5.22 to 12.39) between the printed samples with some materials being comparable to commercial tissue-mimicking materials and good substitutes to a range of materials from lung to bone. Printer settings can result in directional dependency and significantly affect the homogeneity of the samples.Significance. The use of DECT to extract RED, andZeffallows for quantitative imaging and dosimetry using 3D printed materials equivalent to certified tissue-mimicking tissues.
Collapse
Affiliation(s)
- Gabriel P Fonseca
- Department of Radiation Oncology (Maastro), GROW School for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Behzad Rezaeifar
- Department of Radiation Oncology (Maastro), GROW School for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Niklas Lackner
- Department of Radiation Oncology (Maastro), GROW School for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Britt Haanen
- Department of Radiation Oncology (Maastro), GROW School for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Brigitte Reniers
- Research group NuTeC, Centre for Environmental Sciences, Hasselt University, Diepenbeek, Belgium
| | - Frank Verhaegen
- Department of Radiation Oncology (Maastro), GROW School for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands
| |
Collapse
|
17
|
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.
Collapse
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
| |
Collapse
|
18
|
Kunert P, Trinkl S, Giussani A, Reichert D, Brix G. Tissue equivalence of 3D printing materials with respect to attenuation and absorption of X-rays used for diagnostic and interventional imaging. Med Phys 2022; 49:7766-7778. [PMID: 36121424 DOI: 10.1002/mp.15987] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/1912] [Revised: 12/12/1912] [Accepted: 12/12/1912] [Indexed: 12/27/2022] Open
Abstract
INTRODUCTION Three-dimensional printing is a promising technology to produce phantoms for quality assurance and dosimetry in X-ray imaging. Crucial to this, however, is the use of tissue equivalent printing materials. It was thus the aim of this study to evaluate the properties of a larger number of commercially available printing filaments with respect to their attenuation and absorption of X-rays. MATERIALS AND METHODS Apparent kerma attenuation coefficients (AKACs) and absorbed doses for different X-ray spectra (tube voltages, 70-140 kV) were measured and simulated by Monte-Carlo computations for a larger number of fused-deposition-modeling (FDM) materials. The results were compared with the respective values simulated for reference body tissues. In addition, the properties of polylactide acid samples printed with reduced infill densities were investigated. RESULTS Measured and simulated AKACs and absorbed doses agreed well with each other and in case of AKACs also with attenuation coefficients derived from the reference database of the National Institute of Standards and Technology (NIST). For lung, adipose, muscle, and bulk soft tissue as well as for spongiosa (cancellous bone), printed materials with equivalent attenuation as well as absorption properties could be identified. In contrast, none of the considered printed materials was equivalent to cortical bone. CONCLUSION Several FDM materials have been identified as well-suited substitutes for body tissues in terms of the investigated material characteristics. They can therefore be used for in-house production of individualized and task-specific phantoms for image quality assessment and dose measurements in X-ray imaging.
Collapse
Affiliation(s)
- Patrizia Kunert
- Department of Medical and Occupational Radiation Protection, Federal Office for Radiation Protection, Oberschleissheim, Germany
| | - Sebastian Trinkl
- Department of Medical and Occupational Radiation Protection, Federal Office for Radiation Protection, Oberschleissheim, Germany
| | - Augusto Giussani
- Department of Medical and Occupational Radiation Protection, Federal Office for Radiation Protection, Oberschleissheim, Germany
| | - Detlef Reichert
- Department of Physics, Martin-Luther University Halle-Wittenberg, Halle, Germany
| | - Gunnar Brix
- Department of Medical and Occupational Radiation Protection, Federal Office for Radiation Protection, Oberschleissheim, Germany
| |
Collapse
|
19
|
Fabrication of 3D printed head phantom using plaster mixed with polylactic acid powder for patient-specific QA in intensity-modulated radiotherapy. Sci Rep 2022; 12:17500. [PMID: 36261615 PMCID: PMC9581964 DOI: 10.1038/s41598-022-22520-6] [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: 06/16/2022] [Accepted: 10/17/2022] [Indexed: 01/12/2023] Open
Abstract
This study aimed to fabricate a heterogeneous phantom replicating the commercial Rando phantom by mixing plaster powder and polylactic acid (PLA) powder. Producing a heterogeneous phantom using Plaster and PLA is cheaper because it can be easily obtained in the commercial market. Additionally, patient-specific Quality Assurance can be easily performed because the phantom can be produced based on the patient's CT image. PLA has been well studied in the field of radiation therapy and was found to be safe and effective. To match the mean Hounsfield unit (HU) values of the Rando phantom, the bone tissue was changed using plaster and 0-35% PLA powder until an appropriate HU value was obtained, and soft tissue was changed using the PLA infill value until an appropriate HU value was obtained. Bone tissue (200 HU or higher), soft issue (- 500 to 200 HU), and air cavity (less than - 500 HU) were modeled based on the HU values on the computed tomography (CT) image. The bone tissue was modeled as a cavity, and after three-dimensional (3D) printing, a solution containing a mixture of plaster and PLA powder was poured. To evaluate the bone implementation of the phantom obtained by the mixture of plaster and PLA powder, the HU profile of the CT images of the 3D-printed phantom using only PLA and the Rando phantom printed using only PLA was evaluated. The mean HU value for soft tissue in the Rando phantom (- 22.5 HU) showed the greatest similarity to the result obtained with an infill value of 82% (- 20 HU). The mean HU value for bone tissue (669 HU) showed the greatest similarity to the value obtained with 15% PLA powder (680 HU). Thus, for the phantom composed of plaster mixed with PLA powder, soft tissue was fabricated using a 3D printer with an infill value of 82%, and bone tissue was fabricated with a mixture containing 15% PLA powder. In the HU profile, this phantom showed a mean difference of 61 HU for soft tissue and 109 HU for bone tissue in comparison with the Rando phantom. The ratio of PLA powder and plaster can be adjusted to achieve an HU value similar to bone tissue. A simple combination of PLA powder and plaster enabled the creation of a custom phantom that showed similarities to the Rando phantom in both soft tissue and bone tissue.
Collapse
|
20
|
Pereira DD, Cardoso SC, Batista DV, de Souza FM, de Sousa JV, Gonçalves OD, da Rosa LA. Development of an anthropomorphic phantom based on 3D printing for assessment of dose delivered to the eye and adjacent tissues. Radiat Phys Chem Oxf Engl 1993 2022. [DOI: 10.1016/j.radphyschem.2022.110292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
21
|
Bulavskaya A, Cherepennikov Y, Gavrikov B, Grigorieva A, Grigoriev E, Miloichikova I, Stuchebrov S. Applicability of Poly(styrene-butadiene-styrene) for Three-Dimensional Printing of Tissue-Equivalent Samples. 3D PRINTING AND ADDITIVE MANUFACTURING 2022; 9:399-404. [PMID: 36660294 PMCID: PMC9831560 DOI: 10.1089/3dp.2021.0028] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Several crucial and impactful three-dimensional (3D) printing applications have been developed within a broad range of fields. Among these, revolutionary changes in health care are highly anticipated. The use of 3D printing in medical applications indicates significant promise in terms of medical device personalization, drug delivery, and economical efficiency. However, despite recent significant advances in medicine inspired by 3D printing, scientific challenges and regulatory subtleties remain. This study considers additive technology application in radiotherapy. One of the main requirements for 3D-printed samples' use in radiotherapy is the tissue equivalence of the sample material. In this study, selected parameters of 3D-printed samples made of poly(styrene-butadiene-styrene) (SBS plastic) are obtained, that is, effective atomic number, mass and electron density, and Hounsfield units. The obtained parameters are compared with corresponding values for human tissue and organs. Experimental results demonstrate the tissue equivalency of the considered samples, which can be used in different applications in medical physics and radiotherapy. The obtained results have significant importance for the development, design, and production of samples for medical applications using 3D printing.
Collapse
Affiliation(s)
- Angelina Bulavskaya
- Research School of High-Energy Physics, School of Nuclear Science and Engineering, National Research Tomsk Polytechnic University, Tomsk, Russia
| | - Yury Cherepennikov
- Research School of High-Energy Physics, School of Nuclear Science and Engineering, National Research Tomsk Polytechnic University, Tomsk, Russia
| | - Boris Gavrikov
- The 1st Radiological Department, Moscow City Oncological Hospital No. 62, Istra, Russian Federation
| | - Anna Grigorieva
- Research School of High-Energy Physics, School of Nuclear Science and Engineering, National Research Tomsk Polytechnic University, Tomsk, Russia
| | - Evgeny Grigoriev
- Radiotherapy Department, Cancer Research Institute of Tomsk NRMC, Tomsk, Russia
| | - Irina Miloichikova
- Research School of High-Energy Physics, School of Nuclear Science and Engineering, National Research Tomsk Polytechnic University, Tomsk, Russia
- Radiotherapy Department, Cancer Research Institute of Tomsk NRMC, Tomsk, Russia
| | - Sergei Stuchebrov
- Research School of High-Energy Physics, School of Nuclear Science and Engineering, National Research Tomsk Polytechnic University, Tomsk, Russia
| |
Collapse
|
22
|
Okkalidis N, Bliznakova K, Kolev N. A filament 3D printing approach for CT-compatible bone tissues replication. Phys Med 2022; 102:96-102. [PMID: 36162230 DOI: 10.1016/j.ejmp.2022.09.009] [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: 01/13/2022] [Revised: 09/09/2022] [Accepted: 09/14/2022] [Indexed: 10/14/2022] Open
Abstract
PURPOSE The aim of this study is the development of a methodology for manufacturing 3D printed anthropomorphic structures, which mimic the X-ray properties of the human bone tissue. METHODS A mixing approach of two different materials is proposed for the fabrication of a radiologically equivalent hip bone for an anthropomorphic abdominal phantom. The materials employed for the phantom were polylactic acid (PLA) and Stonefil, while a custom-made dual motor filament extrusion setup and a custom-made software associating medical images directly with the 3D printing process were employed. RESULTS Three phantoms representing the hip bone were 3D printed utilizing two filaments under three different printing scenarios. The phantoms are based on a patient's abdominal CT scan images. Histograms of CT scans of the printed hip bone phantoms were calculated and compared to the original patient's hip bone histogram, demonstrating that a constant mixing composition of 30% Stonefil and 70% PLA with 0.0375 extrusion rate per voxel (93.75% flow for fulfilling a single voxel) for the cancellous bone, and using 100% Stonefil with 0.04 extrusion rate per voxel (100% flow) for the cortical bone results in a realistic anatomy replication of the hip bone. Reproduced HU varied between 700 and 800, which are close to those of the hip bone. CONCLUSIONS The study demonstrated that it is possible to mix two different filaments in real-time during the printing process to obtain phantoms with realistic and radiographically bone tissue equivalent attenuation. The results will be explored for manufacturing a CT-compatible abdominal phantom.
Collapse
Affiliation(s)
- Nikiforos Okkalidis
- Medical University of Varna, Bulgaria; Morphé, Praxitelous 1, Thessaloniki, Greece.
| | | | - Nikola Kolev
- Medical University of Varna, Bulgaria; First Clinic of Surgery in UMHAT "Saint Marina", Varna, Bulgaria
| |
Collapse
|
23
|
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.
Collapse
|
24
|
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.
Collapse
Affiliation(s)
- Nikiforos Okkalidis
- Research Institute, Medical University of Varna, Bulgaria.,Morphé, Praxitelous 1, Thessaloniki, Greece
| |
Collapse
|
25
|
Additively manufactured test phantoms for mimicking soft tissue radiation attenuation in CBCT using Polyjet technology. Z Med Phys 2022:S0939-3889(22)00063-0. [PMID: 35792011 DOI: 10.1016/j.zemedi.2022.05.002] [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] [Received: 01/06/2022] [Revised: 04/27/2022] [Accepted: 05/27/2022] [Indexed: 01/14/2023]
Abstract
OBJECTIVES To develop and validate a simple approach for building cost-effective imaging phantoms for Cone Beam Computed Tomography (CBCT) using a modified Polyjet additive manufacturing technology where a single material can mimic a range of human soft-tissue radiation attenuation. MATERIALS AND METHODS Single material test phantoms using a cubic lattice were designed in 3-Matic 15.0 software . Keeping the individual cubic lattice volume constant, eight different percentage ratio (R) of air: material from 0% to 70% with a 10% increment were assigned to each sample. The phantoms were printed in three materials, namely Vero PureWhite, VeroClear and TangoPlus using Polyjet technology. The CT value analysis, non-contact profile measurement and microCT-based volumetric analysis was performed for all the samples. RESULTS The printed test phantoms produced a grey value spectrum equivalent to the radiation attenuation of human soft tissues in the range of -757 to +286 HU on CT. The results from dimensional comparison analysis of the printed phantoms with the digital test phantoms using non-contact profile measurement showed a mean accuracy of 99.07 % and that of micro-CT volumetric analysis showed mean volumetric accuracy of 84.80-94.91%. The material and printing costs of developing 24 test phantoms was 83.00 Euro. CONCLUSIONS The study shows that additive manufacturing-guided macrostructure manipulation modifies successfully the radiographic visibility of a material in CBCT imaging with 1 mm3 resolution, helping customization of imaging phantoms.
Collapse
|
26
|
Chabod S, Giraud J, Hervé M, Santos D, Sauzet N. Heavy-water-based moderator design for an AB-BNCT unit using a topology optimization algorithm. Phys Med Biol 2022; 67. [DOI: 10.1088/1361-6560/ac6723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 04/13/2022] [Indexed: 11/11/2022]
Abstract
Abstract
Objective. The design of neutron moderators for BNCT treatment units currently relies on parametric approaches, which yield quality results but are ultimately limited by human imagination. Efficient but non-intuitive design solutions may thus be missed out. This limitation needs to be addressed. Approach. To overcome this limitation, we propose to use a topology optimization algorithm coupled with a state-of-the-art Monte-Carlo transport code. This approach recently proved capable of finding complex optimal configurations of particle propagators with limited human intervention. Main results. In this study, we apply this algorithmic solution to optimize some heavy-water neutron moderators for a specific AB-BNCT treatment unit. The moderators thus generated are compact yet succeed in limiting the exposure of patient’s healthy tissues to levels below recommended limits. They present subtle, original geometries inaccessible to standard parametric approaches or human intuition. Significance. This approach could be used to automatically fit the design of a BNCT moderator to the location and shape of the tumor or to the morphology of the patient to be treated, opening a path for more targeted BNCT treatment.
Collapse
|
27
|
Mariyappan K, Tandon A, Park S, Kokkiligadda S, Lee J, Jo S, Komarala EP, Yoo S, Chopade P, Choi HJ, Lee CW, Jeon S, Jeong JH, Park SH. Nanomaterial-Embedded DNA Films on 2D Frames. ACS APPLIED BIO MATERIALS 2022; 5:2812-2818. [PMID: 35543024 DOI: 10.1021/acsabm.2c00227] [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: 11/29/2022]
Abstract
Recently, 3D printing has provided opportunities for designing complex structures with ease. These printed structures can serve as molds for complex materials such as DNA and cetyltrimethylammonium chloride (CTMA)-modified DNA that have easily tunable functionalities via the embedding of various nanomaterials such as ions, nanoparticles, fluorophores, and proteins. Herein, we develop a simple and efficient method for constructing DNA flat and curved films containing water-soluble/thermochromatic dyes and di/trivalent ions and CTMA-modified DNA films embedded with organic light-emitting molecules (OLEM) with the aid of 2D/3D frames made by a 3D printer. We study the Raman spectra, current, and resistance of Cu2+-doped and Tb3+-doped DNA films and the photoluminescence of OLEM-embedded CTMA-modified DNA films to better understand the optoelectric characteristics of the samples. Compared to pristine DNA, ion-doped DNA films show noticeable variation of Raman peak intensities, which might be due to the interaction between the ion and phosphate backbone of DNA and the intercalation of ions in DNA base pairs. As expected, ion-doped DNA films show an increase of current with an increase in bias voltage. Because of the presence of metallic ions, DNA films with embedded ions showed relatively larger current than pristine DNA. The photoluminescent emission peaks of CTMA-modified DNA films with OLEMRed, OLEMGreen, and OLEMBlue were obtained at the wavelengths of 610, 515, and 469 nm, respectively. Finally, CIE color coordinates produced from CTMA-modified DNA films with different OLEM color types were plotted in color space. It may be feasible to produce multilayered DNA films as well. If so, multilayered DNA films embedded with different color dyes, ions, fluorescent materials, nanoparticles, proteins, and drug molecules could be used to realize multifunctional physical devices such as energy harvesting and chemo-bio sensors in the near future.
Collapse
Affiliation(s)
- Karthikeyan Mariyappan
- Department of Physics, Institute of Basic Science, and Sungkyunkwan Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon 16419, Korea
| | - Anshula Tandon
- Department of Physics, Institute of Basic Science, and Sungkyunkwan Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon 16419, Korea
| | - Suyoun Park
- Department of Physics, Institute of Basic Science, and Sungkyunkwan Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon 16419, Korea
| | - Samanth Kokkiligadda
- Department of Physics, Institute of Basic Science, and Sungkyunkwan Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon 16419, Korea
| | - Jayeon Lee
- Department of Physics, Institute of Basic Science, and Sungkyunkwan Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon 16419, Korea
| | - Soojin Jo
- Department of Physics, Institute of Basic Science, and Sungkyunkwan Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon 16419, Korea
| | - Eswaravara Prasadarao Komarala
- Department of Physics, Institute of Basic Science, and Sungkyunkwan Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon 16419, Korea
| | - Sanghyun Yoo
- Department of Physics, Institute of Basic Science, and Sungkyunkwan Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon 16419, Korea
| | - Prathamesh Chopade
- Department of Physics, Institute of Basic Science, and Sungkyunkwan Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon 16419, Korea
| | - Hee Jin Choi
- Institute of Advanced Optics and Photonics, Department of Applied Optics, Hanbat National University, Daejeon 34158, Korea
| | - Chang-Won Lee
- Institute of Advanced Optics and Photonics, Department of Applied Optics, Hanbat National University, Daejeon 34158, Korea
| | - Sohee Jeon
- Nanomechanical Systems Research Division, Korea Institute of Machinery and Materials (KIMM), Daejeon 34103, Korea
| | - Jun-Ho Jeong
- Nanomechanical Systems Research Division, Korea Institute of Machinery and Materials (KIMM), Daejeon 34103, Korea.,Department of Nanomechatronics, Korea University of Science and Technology (UST), Daejeon 34113, Korea
| | - Sung Ha Park
- Department of Physics, Institute of Basic Science, and Sungkyunkwan Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon 16419, Korea
| |
Collapse
|
28
|
Tillery H, Moore M, Gallagher KJ, Taddei PJ, Leuro E, Argento DC, Moffitt GB, Kranz M, Carey M, Heymsfield S, Newhauser WD. Personalized 3D-printed anthropomorphic whole-body phantom irradiated by protons, photons, and neutrons. Biomed Phys Eng Express 2022; 8. [PMID: 35045408 DOI: 10.1088/2057-1976/ac4d04] [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: 10/24/2021] [Accepted: 01/19/2022] [Indexed: 11/12/2022]
Abstract
The objective of this study was to confirm the feasibility of three-dimensionally-printed (3D-printed), personalized whole-body anthropomorphic phantoms for radiation dose measurements in a variety of charged and uncharged particle radiation fields. We 3D-printed a personalized whole-body phantom of an adult female with a height of 154.8 cm, mass of 90.7 kg, and body mass index of 37.8 kg/m2. The phantom comprised of a hollow plastic shell filled with water and included a watertight access conduit for positioning dosimeters. It is compatible with a wide variety of radiation dosimeters, including ionization chambers that are suitable for uncharged and charged particles. Its mass was 6.8 kg empty and 98 kg when filled with water. Watertightness and mechanical robustness were confirmed after multiple experiments and transportations between institutions. The phantom was irradiated to the cranium with therapeutic beams of 170-MeV protons, 6-MV photons, and fast neutrons. Radiation absorbed dose was measured from the cranium to the pelvis along the longitudinal central axis of the phantom. The dose measurements were made using established dosimetry protocols and well-characterized instruments. For the therapeutic environments considered in this study, stray radiation from intracranial treatment beams was the lowest for proton therapy, intermediate for photon therapy, and highest for neutron therapy. An illustrative example set of measurements at the location of the thyroid for a square field of 5.3 cm per side resulted in 0.09, 0.59, and 1.93 cGy/Gy from proton, photon, and neutron beams, respectively. In this study, we found that 3D-printed personalized phantoms are feasible, inherently reproducible, and well-suited for therapeutic radiation measurements. The measurement methodologies we developed enabled the direct comparison of radiation exposures from neutron, proton, and photon beam irradiations.
Collapse
Affiliation(s)
- Hunter Tillery
- Radiation Medicine, Oregon Health & Science University, 3181 S.W. Sam Jackson Park Road, KPV4, Portland, Oregon, 97239-3098, UNITED STATES
| | - Meagan Moore
- Louisiana State University, 439-B Nicholson Hall, Tower Dr., Baton Rouge, Louisiana, 70803-4001, UNITED STATES
| | - Kyle Joseph Gallagher
- Radiation Medicine, Oregon Health & Science University, 3181 S.W. Sam Jackson Park Road, KPV4, Portland, Oregon, 97239-3098, UNITED STATES
| | - Phillip J Taddei
- Department of Radiation Oncology, Mayo Clinic, 200 First St. SW, Rochester, Minnesota, 55905, UNITED STATES
| | - Eric Leuro
- Seattle Cancer Care Alliance, 1570 N 115th St, Seattle, Washington, 98133, UNITED STATES
| | - David C Argento
- Radiation Oncology, University of Washington School of Medicine, 1959 NE Pacific St, Seattle, Washington, 98195, UNITED STATES
| | - Gregory B Moffitt
- Radiation Oncology, University of Washington School of Medicine, 1959 NE Pacific St, Seattle, Washington, 98195, UNITED STATES
| | - Marissa Kranz
- University of Washington School of Medicine, 1959 NE Pacific St, Seattle, Washington, 98195, UNITED STATES
| | - Margaret Carey
- Louisiana State University, 439-B Nicholson Hall, Tower Dr., Baton Rouge, Louisiana, 70803-4001, UNITED STATES
| | - Steven Heymsfield
- Louisiana State University, 439-B Nicholson Hall, Tower Dr., Baton Rouge, Louisiana, 70803-4001, UNITED STATES
| | - Wayne David Newhauser
- Louisiana State University, 439-B Nicholson Hall, Tower Dr., Baton Rouge, Louisiana, 70803-4001, UNITED STATES
| |
Collapse
|
29
|
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.
Collapse
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
| |
Collapse
|
30
|
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.
Collapse
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
| |
Collapse
|
31
|
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.
Collapse
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
| |
Collapse
|
32
|
Zhang C, Hu W, Zhou Q, He J, Wang H, Qiu K, Wang L, Li X. The possibility of developing customized 3D-printed silicone hydrogel bolus for post-mastectomy radiotherapy. JOURNAL OF RADIATION RESEARCH AND APPLIED SCIENCES 2021. [DOI: 10.1080/16878507.2021.1962629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Caixun Zhang
- Department of Radiotherapy, Renmin Hospital of Wuhan University, Wuhan, P .R. China
| | - Weiguo Hu
- Department of Oncology Center, Renmin Hospital of Wuhan University, Wuhan, P .R. China
| | - Qing Zhou
- Department of Ultrasound, Renmin Hospital of Wuhan University, Wuhan, P .R. China
| | - Junxiang He
- Department of Radiotherapy, Renmin Hospital of Wuhan University, Wuhan, P .R. China
| | - Hao Wang
- Department of Ultrasound, Renmin Hospital of Wuhan University, Wuhan, P .R. China
| | - Kehu Qiu
- Department of Oncology Center, Renmin Hospital of Wuhan University, Wuhan, P .R. China
| | - Luzhou Wang
- Department of Radiotherapy, Renmin Hospital of Wuhan University, Wuhan, P .R. China
| | - Xiangpan Li
- Department of Radiotherapy, Renmin Hospital of Wuhan University, Wuhan, P .R. China
| |
Collapse
|
33
|
Kariyawasam LN, Ng CKC, Sun Z, Kealley CS. Use of Three-Dimensional Printing in Modelling an Anatomical Structure with a High Computed Tomography Attenuation Value: A Feasibility Study. JOURNAL OF MEDICAL IMAGING AND HEALTH INFORMATICS 2021. [DOI: 10.1166/jmihi.2021.3664] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Introduction: Three-dimensional (3D) printing provides an opportunity to develop anthropomorphic computed tomography (CT) phantoms with anatomical and radiological features mimicking a range of patients’ conditions, thus allowing development of individualised, low dose
scanning protocols. However, previous studies of 3D printing in CT phantom development could only create anatomical structures using potassium iodide with attenuation values up to 1200 HU which is insufficient to mimic the radiological features of some high attenuation structures such as cortical
bone. This study aimed at investigating the feasibility of using 3D printing in modelling cortical bone with a non-iodinated material. Methods: This study had 2 stages. Stage 1 involved a vat photopolymerisation 3D printer to directly print cube phantoms with different percentage compositions
of calcium phosphate (CP) and resin (approach 1), and approach 2 using a material extrusion 3D printer to develop a cube mould for infilling of the CP with hardener as the phantom. The approach able to create the cube phantom with the CT attenuation value close to that of a tibial mid-diaphysis
cortex of a real patient, 1475±205 HU was employed to develop a tibial mid-diaphysis phantom. The mean CT numbers of the cube and tibia phantoms were measured and compared with that of the original CT dataset through unpaired t-test. Results: All phantoms were scanned by CT using
a lower extremity scanning protocol. The moulding approach was selected to develop the tibia middiaphysis phantom with CT attenuation value, 1434±184 HU which was not statistically significantly different from the one of the original dataset (p = 0.721). Conclusion: This
study demonstrates the feasibility to use the material extrusion 3D printer to create a tibial mid-diaphysis mould for infilling of the CP as an anthropomorphic CT phantom and the attenuation value of its cortex matches the real patient’s one.
Collapse
Affiliation(s)
- Lakna N. Kariyawasam
- Discipline of Medical Radiation Science, School of Molecular and Life Sciences, Curtin University, Perth, Western Australia 6845, Australia
| | - Curtise K. C. Ng
- Discipline of Medical Radiation Science, School of Molecular and Life Sciences, Curtin University, Perth, Western Australia 6845, Australia
| | - Zhonghua Sun
- Discipline of Medical Radiation Science, School of Molecular and Life Sciences, Curtin University, Perth, Western Australia 6845, Australia
| | - Catherine S. Kealley
- Discipline of Medical Radiation Science, School of Molecular and Life Sciences, Curtin University, Perth, Western Australia 6845, Australia
| |
Collapse
|
34
|
Goodall SK, Rampant P, Smith W, Waterhouse D, Rowshanfarzad P, Ebert MA. Investigation of the effects of spinal surgical implants on radiotherapy dosimetry: A study of 3D printed phantoms. Med Phys 2021; 48:4586-4597. [PMID: 34214205 DOI: 10.1002/mp.15070] [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: 01/27/2021] [Revised: 04/29/2021] [Accepted: 06/12/2021] [Indexed: 01/22/2023] Open
Abstract
PURPOSE The use of three-dimensional (3D) printing to develop custom phantoms for dosimetric studies in radiotherapy is increasing. The process allows production of phantoms designed to evaluated specific geometries, patients, or patient groups with a defining feature. The ability to print bone-equivalent phantoms has, however, proved challenging. The purpose of this work was to 3D print a series of three similar spine phantoms containing no surgical implants, implants made of titanium, and implants made of carbon fiber, for future dosimetric and imaging studies. Phantoms were evaluated for (a) tissue and bone equivalence, (b) geometric accuracy compared to design, and (c) similarity to one another. METHODS Sample blocks of PLA, HIPS, and StoneFil PLA-concrete with different infill densities were printed to evaluate tissue and bone equivalence. The samples were used to develop CT to physical (PD) and effective relative electron density (REDeff ) conversion curves and define the settings for printing the phantoms. CT scans of the printed phantoms were obtained to assess the geometry and densities achieved. Mean distance to agreement (MDA) and DICE coefficient (DSC) values were calculated between contours defining the different materials, obtained from design and like phantom modules. HU values were used to determine PD and REDeff and subsequently evaluate tissue and bone equivalence. RESULTS Sample objects showed linear relationships between HU and both PD and REDeff for both PLA and StoneFil. The PD and REDeff of the objects calculated using clinical CT conversion curves were not accurate and custom conversion curves were required. PLA printed with 90% infill density was found to have a PD of 1.11 ± 0.03 g.cm-3 and REDeff of 1.04 ± 0.02 and selected for tissue- equivalent phantom elements. StoneFil printed with 100% infill density showed a PD of 1.35 ± 0.03 g.cm-3 and REDeff of 1.24 ± 0.04 and was selected for bone-equivalent elements. Upon evaluation of the final phantoms, the PLA elements displayed PD in the range of 1.10 ± 0.03 g.cm-3 -1.13 ± 0.03 g.cm-3 and REDeff in the range of 1.02 ± 0.03-1.06 ± 0.03. The StoneFil elements showed PD in the range of 1.43 ± 0.04 g.cm-3 -1.46 ± 0.04 g.cm-3 and REDeff in the range of 1.31 ± 0.04-1.33 ± 0.04. The PLA phantom elements were shown to have MDA of ≤1.00 mm and DSC of ≥0.95 compared to design, and ≤0.48 mm and ≥0.91 compared like modules. The StoneFil elements displayed MDA values of ≤0.44 mm and DSC of ≥0.98 compared to design and ≤0.43 mm and ≥0.92 compared like modules. CONCLUSIONS Phantoms which were radiologically equivalent to tissue and bone were produced with a high level of similarity to design and even higher level of similarity of one another. When used in conjunction with the derived CT to PD or REDeff conversion curves they are suitable for evaluating the effects of spinal surgical implants of varying material of construction.
Collapse
Affiliation(s)
- Simon K Goodall
- School of Physics, Mathematics, and Computing, Faculty of Engineering and Mathematical Sciences, University of Western Australia, Crawley, WA, Australia.,GenesisCare, Wembley, WA, Australia
| | | | - Warwick Smith
- School of Physics, Mathematics, and Computing, Faculty of Engineering and Mathematical Sciences, University of Western Australia, Crawley, WA, Australia.,GenesisCare, Wembley, WA, Australia
| | | | - Pejman Rowshanfarzad
- School of Physics, Mathematics, and Computing, Faculty of Engineering and Mathematical Sciences, University of Western Australia, Crawley, WA, Australia
| | - Martin A Ebert
- School of Physics, Mathematics, and Computing, Faculty of Engineering and Mathematical Sciences, University of Western Australia, Crawley, WA, Australia.,Department of Radiation Oncology, Sir Charles Gardiner Hospital, Nedlands, WA, Australia.,5D Clinics, Perth, WA, Australia
| |
Collapse
|
35
|
One layer at a time: the use of 3D printing in the fabrication of cadmium-free electron field shaping devices. JOURNAL OF RADIOTHERAPY IN PRACTICE 2020. [DOI: 10.1017/s1460396920001107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Abstract
Introduction:
Electron blocks are typically composed of a low melting point alloy (LMPA), which is poured into an insert frame containing a manually placed Styrofoam aperture negative used to define the desired field shape. Current implementations of the block fabrication process involve numerous steps which are subjective and prone to user error. Occasionally, bowing of the sides of the insert frame is observed, resulting in premature frame decommissioning. Recent works have investigated the feasibility of utilising 3D printing technology to replace the conventional electron block fabrication workflow; however, these approaches involved long print times, were not compatible with commonly used cadmium-free LMPAs, and did not address the problem of insert frame bowing. In this work, we sought to develop a new 3D printing technique that would remedy these issues.
Materials and Methods:
Electron cutout negatives and alignment jigs were printed using Acrylonitrile Butadiene Styrene, which does not warp at the high temperatures associated with molten cadmium-free alloys. The accuracy of the field shape produced by electron blocks fabricated using the 3D printed negatives was assessed using Gafchromic film and beam profiler measurements. As a proof-of-concept, electron blocks with off-axis apertures, as well as complex multi-aperture blocks to be used for passive electron beam intensity modulation, were also created.
Results:
Film and profiler measurements of field size were in excellent agreement with the values calculated using the Eclipse treatment planning system, showing less than a 1% difference in line profile full-width at half-maximum. The multi-aperture electron blocks produced fields with intensity modulation ≤3.2% of the theoretically predicted value. Use of the 3D printed alignment jig – which has contours designed to match those of the insert frame – was found to reduce the amount of frame bowing by factors of 1.8 and 2.1 in the lateral and superior–inferior directions, respectively.
Conclusions:
The 3D printed ABS negatives generated with our technique maintain their spatial accuracy even at the higher temperatures associated with cadmium-free LMPA. The negatives typically take between 1 and 2 hours to print and have a material cost of approximately $2 per patient.
Collapse
|
36
|
Characterization of 3D-printed bolus produced at different printing parameters. Med Dosim 2020; 46:157-163. [PMID: 33172711 DOI: 10.1016/j.meddos.2020.10.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 09/17/2020] [Accepted: 10/20/2020] [Indexed: 11/20/2022]
Abstract
We aimed to analyze the effects of printing parameters on characterization of three-dimensional (3D) printed bolus used in external beam radiotherapy. Two sets of measurements were performed to investigate the dosimetric and physical characterization of 3D-printed bolus at different printing parameters. In the first step, boluses were produced at different infill-percentages, infill-patterns and printing directions. Two-dimensional (2D) dose measurements were performed in Elekta Versa HD linear accelerator using 6 MV photon energy. Measured 2D dose maps for both printed and reference bolus materials were compared using the 2D gamma analysis method. Additionally, patient-specific bolus was produced with defined optimum printing parameters for anthropomorphic head and neck phantom. Then, point dose measurements were performed to evaluate the feasibility of printed bolus in clinical use. In the second step, physical measurements were carried out to evaluate the printing accuracy, the mean hounsfield unit (HU) value and the weight of 3D-printed boluses. According to our measurement, infill-percentage, infill-pattern and printing direction significantly changed the dosimetric and physical properties of the 3D-printed bolus independently. Maximum gamma passing rate at 1.5 and 5 cm depths were found as 93.8% and 98.8%, respectively, for 60% infill-percentage, sunglass fill infill-pattern and horizontal printing direction. The printing accuracy of the products was within 0.4 mm. Dosimetric and physical properties of the printed bolus material changed significantly with the selected printing parameters. Therefore, it is important to note that each combination of these printing parameters that will be used in the production of patient-specific bolus should be investigated separately.
Collapse
|
37
|
Asfia A, Deepak B, Novak JI, Rolfe B, Kron T. Infill selection for 3D printed radiotherapy immobilisation devices. Biomed Phys Eng Express 2020; 6. [DOI: 10.1088/2057-1976/abb981] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 09/17/2020] [Indexed: 12/19/2022]
|
38
|
|
39
|
Yang H, Ji F, Li Z, Tao S. Preparation of Hydrophobic Surface on PLA and ABS by Fused Deposition Modeling. Polymers (Basel) 2020; 12:polym12071539. [PMID: 32664645 PMCID: PMC7407596 DOI: 10.3390/polym12071539] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 07/02/2020] [Accepted: 07/07/2020] [Indexed: 11/30/2022] Open
Abstract
In the fields of agriculture, medical treatment, food, and packaging, polymers are required to have the characteristics of self-cleaning, anti-icing, and anti-corrosion. The traditional preparation method of hydrophobic coatings is costly and the process is complex, which has special requirements on the surface of the part. In this study, fused deposition modeling (FDM) 3D printing technology with design and processing flexibility was applied to the preparation of hydrophobic coatings on polylactic acid (PLA) and acrylonitrile butadiene styrene (ABS) parts, and the relationship between the printing process parameters and the surface roughness and wettability of the printed test parts was discussed. The experimental results show that the layer thickness and filling method have a significant effect on the surface roughness of the 3D-printed parts, while the printing speed has no effect on the surface roughness. The orthogonal experiment analysis method was used to perform the wettability experiment analysis, and the optimal preparation process parameters were found to be a layer thickness of 0.25 mm, the Grid filling method, and a printing speed of 150 mm/s.
Collapse
|
40
|
Okkalidis N, Marinakis G. Technical Note: Accurate replication of soft and bone tissues with 3D printing. Med Phys 2020; 47:2206-2211. [DOI: 10.1002/mp.14100] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 02/12/2020] [Accepted: 02/12/2020] [Indexed: 12/20/2022] Open
Affiliation(s)
- Nikiforos Okkalidis
- Centre for Biomedical Cybernetics Faculty of Engineering University of Malta Msida MSD2080Malta
| | - George Marinakis
- Rehabilitation Engineering Unit National Rehabilitation Centre 13122Ilion Attica Greece
| |
Collapse
|
41
|
3D printer-based novel intensity-modulated vaginal brachytherapy applicator: feasibility study. J Contemp Brachytherapy 2020; 12:17-26. [PMID: 32190066 PMCID: PMC7073342 DOI: 10.5114/jcb.2020.92407] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 12/18/2019] [Indexed: 12/14/2022] Open
Abstract
Purpose To design a novel high-dose-rate intracavitary applicator which may lead to enhanced dose modulation in the brachytherapy of gynecological cancers. Material and methods A novel brachytherapy applicator, auxiliary equipment and quality control phantom were modeled in SketchUp Pro 2017 modeling software and printed out from a MakerBot Replicator Z18 three-dimensional printer. As a printing material polylactic acid (PLA) filament was used and compensator materials including aluminum, stainless-steel and Cerrobend alloy were selected according to their radiation attenuation properties. To evaluate the feasibility of the novel applicator, two sets of measurements were performed in a Varian GammaMed iX Plus high-dose rate iridium-192 (192Ir) brachytherapy unit and all of the treatment plans were calculated in Varian BrachyVision treatment planning system v.8.9 with TG43-based formalism. In the first step, catheter and source-dwell positioning accuracy, reproducibility of catheter and source positions, linearity of relative dose with changing dwell times and compensator materials were tested to evaluate the mechanical stability of the designed applicator. In the second step, to validate the dosimetric accuracy of the novel applicator measured point dose and two-dimensional dose distributions in homogeneous medium were compared with calculated data in the treatment planning system using PTW VeriSoft v.5.1 software. Results In mechanical quality control tests source-dwell positioning accuracy and linearity of the designed applicator were measured as ≤ 0.5 mm and ≤ 1.5%, respectively. Reproducibility of the treatment planning was ≥ 97.7% for gamma evaluation criteria of 1 mm distance to agreement and 1% dose difference of local dose. In dosimetric quality control tests, maximum difference between measured and calculated point dose was found as 3.8% in homogeneous medium. In two-dimensional analysis, the number of passing points was greater than 90% for all measurements using gamma evaluation criteria of 3 mm distance to agreement and 3% dose difference of local dose. Conclusions The novel brachytherapy applicator met the necessary requirements in quality control tests.
Collapse
|
42
|
Tino R, Yeo A, Leary M, Brandt M, Kron T. A Systematic Review on 3D-Printed Imaging and Dosimetry Phantoms in Radiation Therapy. Technol Cancer Res Treat 2020; 18:1533033819870208. [PMID: 31514632 PMCID: PMC6856980 DOI: 10.1177/1533033819870208] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
INTRODUCTION Additive manufacturing or 3-dimensional printing has become a widespread technology with many applications in medicine. We have conducted a systematic review of its application in radiation oncology with a particular emphasis on the creation of phantoms for image quality assessment and radiation dosimetry. Traditionally used phantoms for quality assurance in radiotherapy are often constraint by simplified geometry and homogenous nature to perform imaging analysis or pretreatment dosimetric verification. Such phantoms are limited due to their ability in only representing the average human body, not only in proportion and radiation properties but also do not accommodate pathological features. These limiting factors restrict the patient-specific quality assurance process to verify image-guided positioning accuracy and/or dose accuracy in "water-like" condition. METHODS AND RESULTS English speaking manuscripts published since 2008 were searched in 5 databases (Google Scholar, Scopus, PubMed, IEEE Xplore, and Web of Science). A significant increase in publications over the 10 years was observed with imaging and dosimetry phantoms about the same total number (52 vs 50). Key features of additive manufacturing are the customization with creation of realistic pathology as well as the ability to vary density and as such contrast. Commonly used printing materials, such as polylactic acid, acrylonitrile butadiene styrene, high-impact polystyrene and many more, are utilized to achieve a wide range of achievable X-ray attenuation values from -1000 HU to 500 HU and higher. Not surprisingly, multimaterial printing using the polymer jetting technology is emerging as an important printing process with its ability to create heterogeneous phantoms for dosimetry in radiotherapy. CONCLUSION Given the flexibility and increasing availability and low cost of additive manufacturing, it can be expected that its applications for radiation medicine will continue to increase.
Collapse
Affiliation(s)
- Rance Tino
- RMIT Centre for Additive Manufacture, Innovative Manufacturing Research Group (Medical Manufacturing), RMIT University, Melbourne, Australia.,ARC Industrial Transformation Training Centre in Additive Biomanufacturing, Queensland University of Technology, Brisbane, Australia.,Physical Sciences Department, Peter MacCallum Cancer Centre, Melbourne, Australia
| | - Adam Yeo
- Physical Sciences Department, Peter MacCallum Cancer Centre, Melbourne, Australia
| | - Martin Leary
- RMIT Centre for Additive Manufacture, Innovative Manufacturing Research Group (Medical Manufacturing), RMIT University, Melbourne, Australia.,ARC Industrial Transformation Training Centre in Additive Biomanufacturing, Queensland University of Technology, Brisbane, Australia
| | - Milan Brandt
- RMIT Centre for Additive Manufacture, Innovative Manufacturing Research Group (Medical Manufacturing), RMIT University, Melbourne, Australia.,ARC Industrial Transformation Training Centre in Additive Biomanufacturing, Queensland University of Technology, Brisbane, Australia
| | - Tomas Kron
- ARC Industrial Transformation Training Centre in Additive Biomanufacturing, Queensland University of Technology, Brisbane, Australia.,Physical Sciences Department, Peter MacCallum Cancer Centre, Melbourne, Australia
| |
Collapse
|
43
|
Anwari V, Lai A, Ursani A, Rego K, Karasfi B, Sajja S, Paul N. 3D printed CT-based abdominal structure mannequin for enabling research. 3D Print Med 2020; 6:3. [PMID: 32026130 PMCID: PMC7003364 DOI: 10.1186/s41205-020-0056-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 01/23/2020] [Indexed: 12/29/2022] Open
Abstract
An anthropomorphic phantom is a radiologically accurate, tissue realistic model of the human body that can be used for research into innovative imaging and interventional techniques, education simulation and calibration of medical imaging equipment. Currently available CT phantoms are appropriate tools for calibration of medical imaging equipment but have major disadvantages for research and educational simulation. They are expensive, lacking the realistic appearance and characteristics of anatomical organs when visualized during X-ray based image scanning. In addition, CT phantoms are not modular hence users are not able to remove specific organs from inside the phantom for research or training purposes. 3D printing technology has evolved and can be used to print anatomically accurate abdominal organs for a modular anthropomorphic mannequin to address limitations of existing phantoms. In this study, CT images from a clinical patient were used to 3D print the following organ shells: liver, kidneys, spleen, and large and small intestines. In addition, fatty tissue was made using modelling beeswax and musculature was modeled using liquid urethane rubber to match the radiological density of real tissue in CT Hounsfield Units at 120kVp. Similarly, all 3D printed organ shells were filled with an agar-based solution to mimic the radiological density of real tissue in CT Hounsfield Units at 120kVp. The mannequin has scope for applications in various aspects of medical imaging and education, allowing us to address key areas of clinical importance without the need for scanning patients.
Collapse
Affiliation(s)
- Vahid Anwari
- Joint Department of Medical Imaging, University Health Network, Toronto, Ontario Canada
- University of Toronto, Toronto, Ontario Canada
| | - Ashley Lai
- Joint Department of Medical Imaging, University Health Network, Toronto, Ontario Canada
| | - Ali Ursani
- Joint Department of Medical Imaging, University Health Network, Toronto, Ontario Canada
| | | | - Behruz Karasfi
- Joint Department of Medical Imaging, University Health Network, Toronto, Ontario Canada
| | - Shailaja Sajja
- Quantitative Imaging for Personalized Cancer Medicine (QIPCM) Advanced Imaging Core Lab, Techna Institute, University Health Network, Toronto, Ontario Canada
| | - Narinder Paul
- Joint Department of Medical Imaging, University Health Network, Toronto, Ontario Canada
- Western University, London, Ontario Canada
- Department of Medical Imaging, London Health Sciences Centre, London, Ontario Canada
| |
Collapse
|
44
|
PLA as a suitable 3D printing thermoplastic for use in external beam radiotherapy. AUSTRALASIAN PHYSICAL & ENGINEERING SCIENCES IN MEDICINE 2019; 42:1165-1176. [DOI: 10.1007/s13246-019-00818-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 11/05/2019] [Indexed: 11/26/2022]
|
45
|
Tino R, Leary M, Yeo A, Brandt M, Kron T. Gyroid structures for 3D-printed heterogeneous radiotherapy phantoms. ACTA ACUST UNITED AC 2019; 64:21NT05. [DOI: 10.1088/1361-6560/ab48ab] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
|
46
|
Irnstorfer N, Unger E, Hojreh A, Homolka P. An anthropomorphic phantom representing a prematurely born neonate for digital x-ray imaging using 3D printing: Proof of concept and comparison of image quality from different systems. Sci Rep 2019; 9:14357. [PMID: 31591433 PMCID: PMC6779877 DOI: 10.1038/s41598-019-50925-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Accepted: 09/19/2019] [Indexed: 02/06/2023] Open
Abstract
An anthropomorphic phantom for image optimization in neonatal radiography was developed, and its usability in optimizing image acquisition and processing demonstrated. The phantom was designed to mimic a patient image of a prematurely born neonate. A clinical x-ray (neonate <1 kg) taken with an effective dose of 11 µSv on a needle-crystal storage phosphor system was retrospectively selected from anonymized images as an appropriate template representing a standard case in neonatology imaging. The low dose level used in clinical imaging results in high image noise content. Therefore, the image had to be processed using structure preserving noise reduction. Pixel values were related to printing material thickness to result in a similar attenuation pattern as the original patient including support mattress. A 3D model generating a similar x-ray attenuation pattern on an image detector as a patient was derived accounting for beam hardening and perspective, and printed using different printing technologies. Best printing quality was achieved using a laser stereolithography printer. Phantom images from different digital radiography systems used in neonatal imaging were compared. Effects of technology, image processing, and radiation dose on diagnostic image quality can be assessed for otherwise identical anthropomorphic neonatal images not possible with patient images, facilitating optimization and standardization of imaging parameters and image appearance.
Collapse
Affiliation(s)
- Nikolaus Irnstorfer
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Ewald Unger
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Azadeh Hojreh
- Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Peter Homolka
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria.
| |
Collapse
|
47
|
Mathew E, Domínguez-Robles J, Stewart SA, Mancuso E, O'Donnell K, Larrañeta E, Lamprou DA. Fused Deposition Modeling as an Effective Tool for Anti-Infective Dialysis Catheter Fabrication. ACS Biomater Sci Eng 2019; 5:6300-6310. [PMID: 33405537 DOI: 10.1021/acsbiomaterials.9b01185] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Catheter-associated infections are a common complication that occurs in dialysis patients. Current strategies to prevent infection include catheter coatings containing heparin, pyrogallol, or silver nanoparticles, which all have an increased risk of causing resistance in bacteria. Therefore, a novel approach for manufacture, such as the use of additive manufacturing (AM), also known as three-dimensional (3D) printing, is required. Filaments were produced by extrusion using thermoplastic polyurethane (TPU) and tetracycline hydrochloride (TC) in various concentrations (e.g., 0, 0.25, 0.5, and 1%). The extruded filaments were used in a fused deposition modeling (FDM) 3D printer to print catheter constructs at varying concentrations. Release studies in phosphate-buffered saline, microbiology studies, thermal analysis, contact angle, attenuated total reflection-Fourier transform infrared, scanning electron microscopy, and X-ray microcomputer tomography (μCT) analysis were conducted on the printed catheters. The results suggested that TC was uniformly distributed within the TPU matrix. The microbiology testing of the catheters showed that devices containing TC had an inhibitory effect on the growth of Staphylococcus aureus NCTC 10788 bacteria. Catheters containing 1% TC maintained inhibitory effect after 10 day release studies. After an initial burst release in the first 24 h, there was a steady release of TC in all concentrations of catheters. 3D-printed antibiotic catheters were successfully printed with inhibitory effect on S. aureus bacteria. Finally, TC containing catheters showed resistance to S. aureus adherence to their surfaces when compared with catheters containing no TC. Catheters containing 1% of TC showed a bacterial adherence reduction of up to 99.97%. Accordingly, the incorporation of TC to TPU materials can be effectively used to prepare anti-infective catheters using FDM. This study highlights the potential for drug-impregnated medical devices to be created through AM.
Collapse
Affiliation(s)
- Essyrose Mathew
- School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, U.K
| | - Juan Domínguez-Robles
- School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, U.K
| | - Sarah A Stewart
- School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, U.K
| | - Elena Mancuso
- Nanotechnology and Integrated Bio-Engineering Centre (NIBEC), Ulster University, Jordanstown Campus BT37 0QB, U.K
| | - Kieran O'Donnell
- Nanotechnology and Integrated Bio-Engineering Centre (NIBEC), Ulster University, Jordanstown Campus BT37 0QB, U.K
| | - Eneko Larrañeta
- School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, U.K
| | - Dimitrios A Lamprou
- School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, U.K
| |
Collapse
|
48
|
Brivio D, Naumann L, Albert S, Sajo E, Zygmanski P. 3D printing for rapid prototyping of low-Z/density ionization chamber arrays. Med Phys 2019; 46:5770-5779. [PMID: 31571224 DOI: 10.1002/mp.13841] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 09/12/2019] [Accepted: 09/12/2019] [Indexed: 12/31/2022] Open
Abstract
PURPOSE To explore 3D printing for rapid development of prototype thin slab low-Z/density ionization chamber arrays viable for custom needs in radiotherapy dosimetry and quality assurance (QA). MATERIALS AND METHODS We designed and fabricated parallel plate ionization chambers and ionization chamber arrays using an off-the-shelf 3D printing equipment. Conductive components of the detectors were made of conductive polylactic acid (cPLA) and insulating components were made of acrylonitrile butadiene styrene (ABS). We characterized the detector responses using a Varian TrueBeam linac at 95 cm SSD in slab solid water phantom at 5 cm depth. We measured the current-voltage (IV) curves, the response to different energy beam lines (2.5 MV, 6 MV, 6 MV FFF) for various dose rates and compared them to responses of a commercial Exradin A12 ionization chamber. We measured off-axis ratio (OAR) for several small field static multi-leaf collimators field sizes (0.5-3 cm) and compared them to OAR data obtained for commissioning of stereotactic radiotherapy. RESULTS We identified the printing capability and the limitations of a low-cost off-the-shelf 3D printer for rapid prototyping of detector arrays. The design of the array with sub-millimeter size features conformed to the 3D printing capabilities. IV-curve for the array showed a strong polarity effect (8%) due to the design. Results for the parallel plate and the array compared well with A12 chamber: monitor unit (MU) dependence for the array was within a few % and the response to different energy beam lines was within 1%. Off-axis dose profiles measured with the array were comparable to dose profiles obtained in water tank and stereotactic diode after accounting for the size of the chambers. Dose error was within 2% at the center of the profile and slightly larger at the penumbra. CONCLUSIONS Rapid prototyping of ion chambers by means of low-cost 3D printing is feasible with certain limitations in the design and spatial accuracy of the printed details.
Collapse
Affiliation(s)
- Davide Brivio
- Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Louise Naumann
- Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Steffen Albert
- Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.,Heidelberg University, Heidelberg, Germany.,University of Massachusetts Lowell, Lowell, MA, USA
| | - Erno Sajo
- University of Massachusetts Lowell, Lowell, MA, USA
| | - Piotr Zygmanski
- Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| |
Collapse
|
49
|
Sasaki DK, McGeachy P, Alpuche Aviles JE, McCurdy B, Koul R, Dubey A. A modern mold room: Meshing 3D surface scanning, digital design, and 3D printing with bolus fabrication. J Appl Clin Med Phys 2019; 20:78-85. [PMID: 31454148 PMCID: PMC6753733 DOI: 10.1002/acm2.12703] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 07/30/2019] [Accepted: 08/01/2019] [Indexed: 11/28/2022] Open
Abstract
Purpose This case series represents an initial experience with implementing 3‐dimensional (3D) surface scanning, digital design, and 3D printing for bolus fabrication for patients with complex surface anatomy where traditional approaches are challenging. Methods and Materials For 10 patients requiring bolus in regions with complex contours, bolus was designed digitally from 3D surface scanning data or computed tomography (CT) images using either a treatment planning system or mesh editing software. Boluses were printed using a fused deposition modeling printer with polylactic acid. Quality assurance tests were performed for each printed bolus to verify density and shape. Results For 9 of 10 patients, digitally designed boluses were used for treatment with no issues. In 1 case, the bolus was not used because dosimetric requirements were met without the bolus. QA tests revealed that the bulk density was within 3% of the reference value for 9 of 12 prints, and with more judicious selection of print settings this could be increased. For these 9 prints, density uniformity was as good as or better than our traditional sheet bolus material. The average shape error of the pieces was less than 0.5 mm, and no issues with fit or comfort were encountered during use. Conclusions This study demonstrates that new technologies such as 3D surface scanning, digital design and 3D printing can be safely and effectively used to modernize bolus fabrication.
Collapse
Affiliation(s)
- David Kiyoshi Sasaki
- Department of Medical Physics, CancerCare Manitoba, Winnipeg, Manitoba, Canada.,Department of Radiology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Philip McGeachy
- Department of Medical Physics, Tom Baker Cancer Centre, Calgary, Alberta, Canada
| | - Jorge E Alpuche Aviles
- Department of Medical Physics, CancerCare Manitoba, Winnipeg, Manitoba, Canada.,Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Boyd McCurdy
- Department of Medical Physics, CancerCare Manitoba, Winnipeg, Manitoba, Canada.,Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba, Canada.,Department of Radiology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Rashmi Koul
- Department of Radiology, University of Manitoba, Winnipeg, Manitoba, Canada.,Department of Radiation Oncology, CancerCare Manitoba, Winnipeg, Manitoba, Canada
| | - Arbind Dubey
- Department of Radiology, University of Manitoba, Winnipeg, Manitoba, Canada.,Department of Radiation Oncology, CancerCare Manitoba, Winnipeg, Manitoba, Canada
| |
Collapse
|
50
|
Kadoya N, Abe K, Nemoto H, Sato K, Ieko Y, Ito K, Dobashi S, Takeda K, Jingu K. Evaluation of a 3D-printed heterogeneous anthropomorphic head and neck phantom for patient-specific quality assurance in intensity-modulated radiation therapy. Radiol Phys Technol 2019; 12:351-356. [PMID: 31364005 DOI: 10.1007/s12194-019-00527-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Revised: 07/21/2019] [Accepted: 07/22/2019] [Indexed: 11/28/2022]
Abstract
We evaluated an anthropomorphic head and neck phantom with tissue heterogeneity, produced using a personal 3D printer, with quality assurance (QA), specific to patients undergoing intensity-modulated radiation therapy (IMRT). Using semi-automatic segmentation, 3D models of bone, soft tissue, and an air-filled cavity were created based on computed tomography (CT) images from patients with head and neck cancer treated with IMRT. For the 3D printer settings, polylactide was used for soft tissue with 100% infill. Bone was reproduced by pouring plaster into the cavity created by the 3D printer. The average CT values for soft tissue and bone were 13.0 ± 144.3 HU and 439.5 ± 137.0 HU, respectively, for the phantom and 12.1 ± 124.5 HU and 771.5 ± 405.3 HU, respectively, for the patient. The gamma passing rate (3%/3 mm) was 96.1% for a nine-field IMRT plan. Thus, this phantom may be used instead of a standard shape phantom for patient-specific QA in IMRT.
Collapse
Affiliation(s)
- Noriyuki Kadoya
- Department of Radiation Oncology, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8574, Japan.
| | - Kota Abe
- Department of Radiation Oncology, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8574, Japan.,Department of Radiation Oncology, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, Tokyo, 113-8677, Japan
| | - Hikaru Nemoto
- Department of Radiation Oncology, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8574, Japan
| | - Kiyokazu Sato
- Department of Radiology, Tohoku University Hospital, Sendai, Miyagi, 980-8574, Japan
| | - Yoshiro Ieko
- Department of Radiation Oncology, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8574, Japan.,Department of Radiation Oncology, Yamagata University Faculty of Medicine, Yamagata, Japan
| | - Kengo Ito
- Department of Radiation Oncology, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8574, Japan
| | - Suguru Dobashi
- Department of Radiological Technology, School of Health Sciences, Faculty of Medicine, Tohoku University, Miyagi, 980-8574, Japan
| | - Ken Takeda
- Department of Radiological Technology, School of Health Sciences, Faculty of Medicine, Tohoku University, Miyagi, 980-8574, Japan
| | - Keiichi Jingu
- Department of Radiation Oncology, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8574, Japan
| |
Collapse
|