scholarly journals Development of Patient Specific Conformal 3D-Printed Devices for Dose Verification in Radiotherapy

2021 ◽  
Vol 11 (18) ◽  
pp. 8657
Author(s):  
Antonio Jreije ◽  
Lalu Keshelava ◽  
Mindaugas Ilickas ◽  
Jurgita Laurikaitiene ◽  
Benas Gabrielis Urbonavicius ◽  
...  

In radiation therapy, a bolus is used to improve dose distribution in superficial tumors; however, commercial boluses lack conformity to patient surface leading to the formation of an air gap between the bolus and patient surface and suboptimal tumor control. The aim of this study was to explore 3D-printing technology for the development of patient-specific conformal 3D-printed devices, which can be used for the radiation treatment of superficial head and neck cancer (HNC). Two 3D boluses (0.5 and 1.0 cm thick) for surface dose build-up and patient-specific 3D phantom were printed based on reconstruction of computed tomography (CT) images of a patient with HNC. The 3D-printed patient-specific phantom indicated good tissue equivalency (HU = −32) and geometric accuracy (DSC = 0.957). Both boluses indicated high conformity to the irregular skin surface with minimal air gaps (0.4–2.1 mm for 0.5 cm bolus and 0.6–2.2 mm for 1.0 cm bolus). The performed dose assessment showed that boluses of both thicknesses have comparable effectiveness, increasing the dose that covers 99% of the target volume by 52% and 26% for single field and intensity modulated fields, respectively, when compared with no bolus case. The performed investigation showed the potential of 3D printing in development of cost effective, patient specific and patient friendly conformal devices for dose verification in radiotherapy.

Cancers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1063
Author(s):  
Antonella Castellano ◽  
Michele Bailo ◽  
Francesco Cicone ◽  
Luciano Carideo ◽  
Natale Quartuccio ◽  
...  

The accuracy of target delineation in radiation treatment (RT) planning of cerebral gliomas is crucial to achieve high tumor control, while minimizing treatment-related toxicity. Conventional magnetic resonance imaging (MRI), including contrast-enhanced T1-weighted and fluid-attenuated inversion recovery (FLAIR) sequences, represents the current standard imaging modality for target volume delineation of gliomas. However, conventional sequences have limited capability to discriminate treatment-related changes from viable tumors, owing to the low specificity of increased blood-brain barrier permeability and peritumoral edema. Advanced physiology-based MRI techniques, such as MR spectroscopy, diffusion MRI and perfusion MRI, have been developed for the biological characterization of gliomas and may circumvent these limitations, providing additional metabolic, structural, and hemodynamic information for treatment planning and monitoring. Radionuclide imaging techniques, such as positron emission tomography (PET) with amino acid radiopharmaceuticals, are also increasingly used in the workup of primary brain tumors, and their integration in RT planning is being evaluated in specialized centers. This review focuses on the basic principles and clinical results of advanced MRI and PET imaging techniques that have promise as a complement to RT planning of gliomas.


The Analyst ◽  
2021 ◽  
Author(s):  
Diwakar M. Awate ◽  
Cicero C. Pola ◽  
Erica Shumaker ◽  
Carmen L Gomes ◽  
Jaime Javier Juarez

Despite having widespread application in the biomedical sciences, flow cytometers have several limitations that prevent their application to point-of-care (POC) diagnostics in resource-limited environments. 3D printing provides a cost-effective approach...


2021 ◽  
Vol 7 ◽  
Author(s):  
Jasamine Coles-Black ◽  
Damien Bolton ◽  
Jason Chuen

Introduction: 3D printed patient-specific vascular phantoms provide superior anatomical insights for simulating complex endovascular procedures. Currently, lack of exposure to the technology poses a barrier for adoption. We offer an accessible, low-cost guide to producing vascular anatomical models using routine CT angiography, open source software packages and a variety of 3D printing technologies.Methods: Although applicable to all vascular territories, we illustrate our methodology using Abdominal Aortic Aneurysms (AAAs) due to the strong interest in this area. CT aortograms acquired as part of routine care were converted to representative patient-specific 3D models, and then printed using a variety of 3D printing technologies to assess their material suitability as aortic phantoms. Depending on the technology, phantoms cost $20–$1,000 and were produced in 12–48 h. This technique was used to generate hollow 3D printed thoracoabdominal aortas visible under fluoroscopy.Results: 3D printed AAA phantoms were a valuable addition to standard CT angiogram reconstructions in the simulation of complex cases, such as short or very angulated necks, or for positioning fenestrations in juxtarenal aneurysms. Hollow flexible models were particularly useful for device selection and in planning of fenestrated EVAR. In addition, these models have demonstrated utility other settings, such as patient education and engagement, and trainee and anatomical education. Further study is required to establish a material with optimal cost, haptic and fluoroscopic fidelity.Conclusion: We share our experiences and methodology for developing inexpensive 3D printed vascular phantoms which despite material limitations, successfully mimic the procedural challenges encountered during live endovascular surgery. As the technology continues to improve, 3D printed vascular phantoms have the potential to disrupt how endovascular procedures are planned and taught.


Symbrachydactyly is a genetical problem occurred to newborn where the newborn experienced underdeveloped or shorten fingers. This condition will limit their normal as even a simple task of holding an item or pushing a button. A device is needed to help them gain a better life. The aim of this project is to fabricate a customized prosthesis hand using 3D printing technology at minimum cost. The proposed prosthetic was not embedded with any electrical component. The patient can only use the wrist to control the prosthetic part which is the prosthetic fingers. The prosthetic hand was also being developed with the patient specific features, which the initial design stage was adapted from a person’s hand geometry using a 3D scanner. Next the model of the prosthesis was analyzed computationally to predict the performance of the product. Different material properties are considered in the analysis to present Polylactic Acid (PLA) and Acrylonitrile Butadiene Styrene (ABS) materials. Then, the prosthesis was fabricated using the 3D printing. The results suggested that PLA material indicated better findings and further be fabricated.


Author(s):  
Chia-An Wu ◽  
Andrew Squelch ◽  
Zhonghua Sun

Aim: To determine a printing material that has both elastic property and radiology equivalence close to real aorta for simulation of endovascular stent graft repair of aortic dissection. Background: With the rapid development of three-dimensional (3D) printing technology, a patient-specific 3D printed model is able to help surgeons to make better treatment plan for Type B aortic dissection patients. However, the radiological properties of most 3D printing materials have not been well characterized. This study aims to investigate the appropriate materials for printing human aorta with mechanical and radiological properties similar to the real aortic computed tomography (CT) attenuation. Objective: Quantitative assessment of CT attenuation of different materials used in 3D printed models of aortic dissection for developing patient-specific 3D printed aorta models to simulate type B aortic dissection. Method: A 25-mm length of aorta model was segmented from a patient’s image dataset with diagnosis of type B aortic dissection. Four different elastic commercial 3D printing materials, namely Agilus A40 and A50, Visijet CE-NT A30 and A70 were selected and printed with different hardness. Totally four models were printed out and conducted CT scanned twice on a 192-slice CT scanner using the standard aortic CT angiography protocol, with and without contrast inside the lumen.Five reference points with region of interest (ROI) of 1.77 mm2 were selected at the aortic wall and intimal flap and their Hounsfield units (HU) were measured and compared with the CT attenuation of original CT images. The comparison between the patient’s aorta and models was performed through a paired-sample t-test to determine if there is any significant difference. Result: The mean CT attenuation of aortic wall of the original CT images was 80.7 HU. Analysis of images without using contrast medium showed that the material of Agilus A50 produced the mean CT attenuation of 82.6 HU, which is similar to that of original CT images. The CT attenuation measured at images acquired with other three materials was significantly lower than that of original images (p<0.05). After adding contrast medium, Visijet CE-NT A30 had an average CT attenuation of 90.6 HU, which is close to that of the original images with statistically significant difference (p>0.05). In contrast, the CT attenuation measured at images acquired with other three materials (Agilus A40, A50 and Visiject CE-NT A70) was 129 HU, 135 HU and 129.6 HU, respectively, which is significantly higher than that of original CT images (p<0.05). Conclusion: Both Visijet CE-NT and Agilus have tensile strength and elongation close to real patient’s tissue properties producing similar CT attenuation. Visijet CE-NT A30 is considered the appropriate material for printing aorta to simulate contrast-enhanced CT imaging of type B aortic dissection. Due to lack of body phantom in the experiments, further research with simulation of realistic anatomical body environment should be conducted.


2020 ◽  
Vol 7 (1) ◽  
pp. 7 ◽  
Author(s):  
Elisa Mussi ◽  
Federico Mussa ◽  
Chiara Santarelli ◽  
Mirko Scagnet ◽  
Francesca Uccheddu ◽  
...  

In brain tumor surgery, an appropriate and careful surgical planning process is crucial for surgeons and can determine the success or failure of the surgery. A deep comprehension of spatial relationships between tumor borders and surrounding healthy tissues enables accurate surgical planning that leads to the identification of the optimal and patient-specific surgical strategy. A physical replica of the region of interest is a valuable aid for preoperative planning and simulation, allowing the physician to directly handle the patient’s anatomy and easily study the volumes involved in the surgery. In the literature, different anatomical models, produced with 3D technologies, are reported and several methodologies were proposed. Many of them share the idea that the employment of 3D printing technologies to produce anatomical models can be introduced into standard clinical practice since 3D printing is now considered to be a mature technology. Therefore, the main aim of the paper is to take into account the literature best practices and to describe the current workflow and methodology used to standardize the pre-operative virtual and physical simulation in neurosurgery. The main aim is also to introduce these practices and standards to neurosurgeons and clinical engineers interested in learning and implementing cost-effective in-house preoperative surgical planning processes. To assess the validity of the proposed scheme, four clinical cases of preoperative planning of brain cancer surgery are reported and discussed. Our preliminary results showed that the proposed methodology can be applied effectively in the neurosurgical clinical practice both in terms of affordability and in terms of simulation realism and efficacy.


Biomolecules ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1577
Author(s):  
Zhonghua Sun

Three-dimensional (3D) printing has been increasingly used in medicine with applications in many different fields ranging from orthopaedics and tumours to cardiovascular disease. Realistic 3D models can be printed with different materials to replicate anatomical structures and pathologies with high accuracy. 3D printed models generated from medical imaging data acquired with computed tomography, magnetic resonance imaging or ultrasound augment the understanding of complex anatomy and pathology, assist preoperative planning and simulate surgical or interventional procedures to achieve precision medicine for improvement of treatment outcomes, train young or junior doctors to gain their confidence in patient management and provide medical education to medical students or healthcare professionals as an effective training tool. This article provides an overview of patient-specific 3D printed models with a focus on the applications in cardiovascular disease including: 3D printed models in congenital heart disease, coronary artery disease, pulmonary embolism, aortic aneurysm and aortic dissection, and aortic valvular disease. Clinical value of the patient-specific 3D printed models in these areas is presented based on the current literature, while limitations and future research in 3D printing including bioprinting of cardiovascular disease are highlighted.


2017 ◽  
Vol 2 (2) ◽  
pp. 98 ◽  
Author(s):  
Guruprasad Kuppu Rao ◽  
Tanmay Shah ◽  
Vijay Dayanand Shetty ◽  
B. Ravi

<p>Management of bone and joint injuries is commonly done by immobilisation using plaster/fibreglass casts. This study describes design and fabrication of patient specific cast using 3D printing.  The 3D printed cast while being patient friendly is superior to earlier casts in healing efficacy and hence redefines the joint immobilisation practice. We present here a case of “walk on brace” design and fabrication using 3D printing. The custom design of ankle immobilisation cast was done for an 18-year-old boy having tibia bone fracture during gymnastic activity. The workflow comprises of anatomical data acquisition, CAD, 3D printing, post processing and clinical approval for use. Additional features such as straps, anti-slip inner surface and tread for floor grip were incorporated in the design. </p>


2021 ◽  
Author(s):  
◽  
Ana Morris

<p>Novel technologies that produce medical models which are synthetic equivalents to human tissue may forever change the way human anatomy and medicine are explored. Medical modelling using a bitmap-based additive manufacturing workflow offers exciting opportunities for medical education, informed consent practices, skills acquisition, pre-operative planning and surgical simulation. Moving medical data from the 2D-world to tactile, highly detailed 3D-printed anatomical models may significantly change how we comprehend the body; revamping everything – from medical education to clinical practice.  Research Problem The existing workflow for producing patient-specific anatomical models from biomedical imaging data involves image thresholding and iso-surface extraction techniques that result in surface meshes (also known as objects or parts). This process restricts shape specification to one colour and density, limiting material blending and resulting in anatomically inequivalent medical models. So, how can the use of 3D-printing go beyond static anatomical replication? Imagine pulling back the layers of tissue to reveal the complexity of a procedure, allowing a family to understand and discuss their diagnosis. Overcoming the disadvantages of static medical models could be a breakthrough in the areas of medical communication and simulation. Currently, patient specific models are either rigid or mesh-based and, therefore, are not equivalents of physiology.  Research Aim The aim of this research is to create tangible and visually compelling patient-specific prototypes of human anatomy, offering an insight into the capabilities of new bitmap-based 3D-printing technology. It proposes that full colour, multi-property, voxel-based 3D-printing can emulate physiology, creating a new format of visual and physical medical communication.  Data Collection and Procedure For this study, biomedical imaging data was converted into multi-property 3D-printed synthetic anatomy by bypassing the conversion steps of traditional segmentation. Bitmap-based 3D-printing allows for the precise control over every 14-micron material droplet or “voxel”.  Control over each voxel involves a process of sending bitmap images to a high-resolution and multi-property 3D-printer. Bitmap-based 3D-printed synthetic medical models – which mimicked the colour and density of human anatomy – were successfully produced.  Findings This research presented a novel and streamlined bitmap-based medical modelling workflow with the potential to save manufacturing time and labour cost. Moreover, this workflow produced highly accurate models with graduated densities, translucency, colour and flexion – overcoming complexities that arise due to our body’s opaqueness. The presented workflow may serve as an incentive for others to investigate bitmap-based 3D-printing workflows for different manufacturing applications.</p>


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