A Dosimetric Comparison of CT- and Photogrammetry- Generated 3D Printed HDR Brachytherapy Surface Applicators

Abstract In this study, we investigate whether an acceptable dosimetric plan can be obtained for a surface applicator designed using photogrammetry and compare the plan quality to a CT-derived applicator. The nose region of a RANDO anthropomorphic phantom was selected as the treatment site due to its high curvature. Photographs were captured using a Nikon D5600 DSLR camera and reconstructed using Agisoft Metashape while CT data was obtained using a Canon Aquillion scanner. Virtual surface applicators were designed in Blender and printed with ABS plastic. Treatment plans with a prescription dose of 3.85 Gy x 10 fractions with 100 % dose to PTV on the bridge of the nose at 2 mm depth were generated separately using AcurosBV in the Varian BrachyVision TPS. PTV D98%, D90% and V100%, and OAR D0.1cc, D2cc and V50% dose metrics and dwell times were evaluated, with the applicator fit assessed by air-gap volume measurements. Both types of surface applicators were printed with minimal defects and visually fitted well to the target area. The measured air-gap volume between the photogrammetry applicator and phantom surface was 44 % larger than the CT-designed applicator, with a mean air gap thickness of 3.24 and 2.88 mm, respectively. The largest difference in the dose metric observed for the PTV and OAR was the PTV V100% of -1.27 % and skin D0.1cc of -0.28 %. PTV D98% and D90% and OAR D2cc and V50% for the photogrammetry based plan were all within 0.5 % of the CT based plan. Total dwell times were also within 5 %. A 3D printed surface applicator for the nose was successfully constructed using photogrammetry techniques. Although it produced a larger air gap between the surface applicator and phantom surface, a clinically acceptable dose plan was created with similar PTV and OAR dose metrics to the CT-designed applicator. Additional future work is required to comprehensively evaluate its suitability in a clinically environment.

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Impact of respiratory motion on breast tangential radiotherapy using the field-in-field technique compared to irradiation using physical wedges

Radiology and Oncology ◽

10.2478/raon-2013-0032 ◽

2014 ◽

Vol 48 (1) ◽

pp. 94-98 ◽

Cited By ~ 6

Author(s):

Hidekazu Tanaka ◽

Shinya Hayashi ◽

Kazuhiro Ohtakara ◽

Hiroaki Hoshi

Keyword(s):

Respiratory Motion ◽

Early Stage ◽

Free Breathing ◽

Ct Images ◽

Data Set ◽

Acceptable Range ◽

Treatment Plans ◽

Prescription Dose ◽

Ct Data ◽

The Impact

Abstract Background. This study aimed to evaluate whether the field-in-field (FIF) technique was more vulnerable to the impact of respiratory motion than irradiation using physical wedges (PWs). Patients and methods. Ten patients with early stage breast cancer were enrolled. Computed tomography (CT) was performed during free breathing (FB). After the FB-CT data set acquisition, 2 additional CT scans were obtained during a held breath after light inhalation (IN) and light exhalation (EX). Based on the FB-CT images, 2 different treatment plans were created for the entire breast for each patient and copied to the IN-CT and EX-CT images. The amount of change in the volume of the target receiving 107%, 95%, and 90% of the prescription dose (V107%, V95%, and V90%, respectively), on the IN-plan and EX-plan compared with the FB-plan were evaluated. Results. The V107%, V95%, and V90% were significantly larger for the IN-plan than for the FB-plan in both the FIF technique and PW technique. While the amount of change in the V107% was significantly smaller in the FIF than in the PW plan, the amount of change in the V95% and V90% was significantly larger in the FIF plan. Thus, the increase in the V107% was smaller while the increases in the V95% and V90% were larger in the FIF than in the PW plan. Conclusions. During respiratory motion, the dose parameters stay within acceptable range irrespective of irradiation technique used although the amount of change in dose parameters was smaller with FIF technique.

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What is plan quality in radiotherapy? The importance of evaluating dose metrics, complexity, and robustness of treatment plans

Radiotherapy and Oncology ◽

10.1016/j.radonc.2020.09.038 ◽

2020 ◽

Vol 153 ◽

pp. 26-33 ◽

Cited By ~ 2

Author(s):

Victor Hernandez ◽

Christian Rønn Hansen ◽

Lamberto Widesott ◽

Anna Bäck ◽

Richard Canters ◽

...

Keyword(s):

Plan Quality ◽

Dose Metrics ◽

Treatment Plans

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Optical fibre based real-time measurements during an LDR prostate brachytherapy implant simulation: using a 3D printed anthropomorphic phantom

Scientific Reports ◽

10.1038/s41598-021-90880-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

P. Woulfe ◽

F. J. Sullivan ◽

L. Byrne ◽

A. J. Doyle ◽

W. Kam ◽

...

Keyword(s):

Optical Fibre ◽

Planning System ◽

Treatment Planning System ◽

Prostate Brachytherapy ◽

Anthropomorphic Phantom ◽

Optical Fibre Sensor ◽

Ldr Brachytherapy ◽

3D Printed ◽

Average Activity ◽

Iodine 125

AbstractAn optical fibre sensor based on radioluminescence, using the scintillation material terbium doped gadolinium oxysulphide (Gd2O2S:Tb) is evaluated, using a 3D printed anthropomorphic phantom for applications in low dose-rate (LDR) prostate brachytherapy. The scintillation material is embedded in a 700 µm diameter cavity within a 1 mm plastic optical fibre that is fixed within a brachytherapy needle. The high spatial resolution dosimeter is used to measure the dose contribution from Iodine-125 (I-125) seeds. Initially, the effects of sterilisation on the sensors (1) repeatability, (2) response as a function of angle, and (3) response as a function of distance, are evaluated in a custom polymethyl methacrylate phantom. Results obtained in this study demonstrate that the output response of the sensor, pre- and post-sterilisation are within the acceptable measurement uncertainty ranging from a maximum standard deviation of 4.7% pre and 5.5% post respectively, indicating that the low temperature sterilisation process does not damage the sensor or reduce performance. Subsequently, an LDR brachytherapy plan reconstructed using the VariSeed treatment planning system, in an anthropomorphic 3D printed training phantom, was used to assess the suitability of the sensor for applications in LDR brachytherapy. This phantom was printed based on patient anatomy, with the volume and dimensions of the prostate designed to represent that of the patient. I-125 brachytherapy seeds, with an average activity of 0.410 mCi, were implanted into the prostate phantom under trans-rectal ultrasound guidance; following the same techniques as employed in clinical practice by an experienced radiation oncologist. This work has demonstrated that this sensor is capable of accurately identifying when radioactive I-125 sources are introduced into the prostate via a brachytherapy needle.

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Customised hybrid CT-MRI 3D-printed model for grade V spondylolisthesis in an adolescent

BMJ Case Reports ◽

10.1136/bcr-2020-239192 ◽

2021 ◽

Vol 14 (3) ◽

pp. e239192

Author(s):

Jayanthi Parthasarathy ◽

Eric A Sribnick ◽

Mai-Lan Ho ◽

Allan Beebe

Keyword(s):

Potential Benefit ◽

High Spatial Resolution ◽

Composite Model ◽

Added Value ◽

Patient Specific ◽

Team Approach ◽

Multidisciplinary Team Approach ◽

3D Printed ◽

Ct Data ◽

Ct And Mri

3D-printed patient-specific models provide added value for initial clinical diagnosis, preoperative surgical and implant planning and patient and trainee education. 3D spine models are usually designed using CT data, due to the ability to rapidly image osseous structures with high spatial resolution. Combining CT and MRI to derive a composite model of bony and neurological anatomy can potentially provide even more useful information for complex cases. We describe such a case involving an adolescent with a grade V spondylolisthesis in which a composite model was manufactured for preoperative and intraoperative evaluation and guidance. We provide a detailed workflow for creating such models and outline their potential benefit in guiding a multidisciplinary team approach.

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Abstract 17070: Engineering a Novel Ex Vivo Heart Simulator for Biomechanical Analysis of the Aortomitral Junction

Circulation ◽

10.1161/circ.142.suppl_3.17070 ◽

2020 ◽

Vol 142 (Suppl_3) ◽

Author(s):

Matthew H Park ◽

Annabel Imbrie-moore ◽

Yuanjia Zhu ◽

Hanjay Wang ◽

Michael J Paulsen ◽

...

Keyword(s):

Cardiac Output ◽

Ex Vivo ◽

Clinical Care ◽

Biomechanical Analysis ◽

Future Experimentation ◽

3D Printed ◽

Biomechanical Changes ◽

Predictive Risk ◽

Future Work

Introduction: Advances in ex vivo heart simulation have enabled the study of valvular biomechanics, disease pathologies, and repair strategies. However, these simulators test the valves in isolation, which does not fully replicate in vivo physiology. We hypothesize that by engineering a simulator that preserves the aortomitral junction, we can better recreate pathophysiologies such as systolic anterior motion (SAM). Here, we present a new heart simulator that preserves and manipulates the native aortomitral physiology. Methods: Our simulator is comprised of three subsystems: the ventricular chamber, atrial chamber, and aortic chamber (Fig A, B). The heart is excised at the apex to preserve the papillary muscles, and the left ventricle, atrial cuff, and aorta are fixed to their respective chambers via hemostatic suturing to 3D-printed elastomeric rings. The chambers are equipped with pressure and flow sensors, and a linear piston pump generates physiologic pressures and flows. The atrial and aortic chambers are mounted on 5-degree-of-freedom arms. To demonstrate system function, we manipulated the aortomitral angle and measured aortic cardiac output. Results: In our testing, we evaluated two unique configurations of an explanted porcine heart, of which the aortomitral angles spanned the SAM predictive risk threshold of <120° (Fig C, D). From the flow readings, we measured a 36% reduction in aortic cardiac output upon decreasing the aortomitral angle by 25°. Conclusions: This work highlights the design and development of an ex vivo heart simulator capable of modeling native aortomitral physiology. Our results point to a clear direction for future experimentation, particularly evaluating the biomechanical changes of the heart based on the aortomitral angle. Future work will utilize this platform to create new models and repair techniques to ultimately improve clinical care of valvular pathologies.

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Diagnostic Potential of 3D-Data–Based Reconstruction Software: An Analysis of the Rare Disease Pattern of Cherubism

The Cleft Palate-Craniofacial Journal ◽

10.1597/07-015.1 ◽

2009 ◽

Vol 46 (2) ◽

pp. 215-219 ◽

Cited By ~ 4

Author(s):

Alexandra Ioana Holst ◽

Ursula Hirschfelder ◽

Stefan Holst

Keyword(s):

3D Visualization ◽

Cone Beam Ct ◽

Permanent Tooth ◽

Individual Treatment ◽

Diagnostic Potential ◽

Disease Pattern ◽

Reconstruction Software ◽

Volume Measurements ◽

Ct Data ◽

Tooth Germs

Cherubism is an autosomal-dominant syndrome characterized by bilateral maxillomandibular bony degeneration, fibrous connective tissue hyperplasia, and displacement of permanent tooth germs. Reossification of the cystic lumen occurs spontaneously, but dislocated teeth must be realigned orthodontically. Advancements in virtual 3D reconstruction of anatomic structures based on computed tomography (CT) or cone beam CT data have provided for more predictable individual treatment planning. We evaluated two software programs for making densitometry and volume measurements of cystic areas in the mandibles, and for 3D visualization of permanent tooth germs within the cystic lumen, in two siblings with cherubism.

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Prosthetic treatment protocol with fixed dental constructions made on 3D printed cast patterns

Archives of Materials Science and Engineering ◽

10.5604/01.3001.0012.0611 ◽

2018 ◽

Vol 1 (90) ◽

pp. 33-40

Author(s):

Dzh. Dzhendov ◽

Iv. Katreva ◽

Ts. Dikova

Keyword(s):

Treatment Plan ◽

Treatment Protocol ◽

Production Method ◽

Conventional Technique ◽

Experimental Investigations ◽

Treatment Protocols ◽

Subjective Factor ◽

Cad Cam ◽

Treatment Plans ◽

3D Printed

Purpose: of the present paper is to develop prosthetic treatment protocol for fixed partial dentures made of 3D printed cast patterns. Design/methodology/approach: The clinical and laboratory protocols for manufacturing of fixed prosthetic constructions upon 3D cast patterns are developed on the basis of the literature review and our previous experimental investigations. Comparison between the conventional technique and innovative approach is made. Findings: The terms "semi-digital treatment plan" and "fully digital treatment plan" are defined according to the way of obtaining data for the virtual 3D model and the production method of the fixed prostheses. A classification of treatment protocols with non-removable partial dentures produced by additive technology is developed. Protocols for "semi" and "fully" digitized treatment plans with fixed partial dentures made by casting with 3D printed models are created. Research limitations/implications: Implementation of the fully digitized protocol for manufacturing of fixed prosthetic constructions via 3D printed prototypes requires specific equipment in the dental office and dental technician laboratory – intraoral scanner and CAD/ CAM system with 3D printing machine. Practical implications: Establishing of systematic clinical and laboratory protocols helps dental specialists to implement the innovative working approach in their practice with no risk of neglecting or omitting of some important procedures which increases the quality and long lasting effect of the dental constructions. Originality/value: Following the developed protocols reduces the role of the subjective factor in production technology of fixed prosthetic constructions while saving labour and time.

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Risk of breast fibrosis following irradiation using a breast-specific SBRT system compared with conventional APBI.

Journal of Clinical Oncology ◽

10.1200/jco.2011.29.27_suppl.116 ◽

2011 ◽

Vol 29 (27_suppl) ◽

pp. 116-116

Author(s):

Z. A. Husain ◽

S. J. Feigenberg ◽

E. Nichols ◽

J. Zhang ◽

C. Yu ◽

...

Keyword(s):

Normal Tissue Complication Probability ◽

Tumor Location ◽

Imaging Studies ◽

Ipsilateral Breast ◽

Treatment Plans ◽

Prescription Dose ◽

Irradiation Unit ◽

Immobilization Device ◽

Biologically Equivalent Dose ◽

Breast Dosimetry

116 Background: To determine the dosimetric characteristics and risk of breast fibrosis using a normal tissue complication probability (NTCP) model in conjunction with a novel preoperative stereotactic radiotherapy system called the GammaPod. Results are compared with linac based post-lumpectomy APBI plans for the same cohort. Methods: The GammaPod breast SBRT system consists of a Co-60 irradiation unit in combination with an immobilization device with embedded fiducials. Eight patients were enrolled in an IRB-approved protocol and underwent CT scans in the prone position with breast immobilization. A preoperative target (GTV) was synthesized to match the tumor location and volume reported in imaging studies obtained prior to surgery (0.3-2.4 cc). The GTV was expanded by 1.5 cm to create a CTV, and a PTV was created using an additional 0.3 cm margin. The PTV was prescribed 25.5 Gy in 3 fx, which is radiobiologically equivalent to conventional APBI doses of 38.5 Gy in 10 fx. Following the radioablative experience in NSCLC, we also planned to deliver 60.0 Gy to the GTV+0.3 cm as a simultaneous boost in conjunction with the 25.5 Gy PTV prescription dose. For comparison, linac-based treatment plans were created for the same cohort following NSABP B-39 guidelines. Whole breast dosimetry was analyzed in terms of biologically equivalent dose (BED) and Lyman NTCP analysis was performed. Results: The volume of ipsilateral breast receiving 10, 20, 50, and 100% of the prescribed dose was substantially smaller in GammaPod vs. APBI plans, with cohort averages of 19.3, 13.0, 7.1 and 4.0% vs. 75.8, 67.3, 48.1 and 27.6% respectively (p<0.001). Even though the PTV equivalent uniform BED (EUD) was substantially higher in GammaPod plans (87.9 Gy vs. 57.3 Gy), the ipsilateral breast EUD was still smaller in these plans, 18.9 ± 5.0 Gy vs. 47.2 ± 3.2 Gy (p<0.001). Corresponding NTCP predictions for breast fibrosis rates following GammaPod and APBI treatments were 0.2 ± 0.1% vs. 2.8 ± 0.8% (p<0.001), respectively. Conclusions: The GammaPod system improves upon traditional post-lumpectomy linac-based APBI by decreasing dose to the ipsilateral breast as well as the predicted rates of breast fibrosis.

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Open Source 3D Printed Lung Tumor Movement Simulator for Radiotherapy Quality Assurance

Materials ◽

10.3390/ma11081317 ◽

2018 ◽

Vol 11 (8) ◽

pp. 1317 ◽

Cited By ~ 3

Author(s):

Darío Quiñones ◽

David Soler-Egea ◽

Víctor González-Pérez ◽

Johanna Reibke ◽

Elena Simarro-Mondejar ◽

...

Keyword(s):

Lung Cancer ◽

Quality Assurance ◽

Side Effects ◽

Causes Of Death ◽

Human Lung ◽

Radiation Treatment ◽

Lung Tumor ◽

Moving Target ◽

Treatment Plans ◽

3D Printed

In OECD (Organization for Economic Co-operation and Development) countries, cancer is one of the main causes of death, lung cancer being one of the most aggressive. There are several techniques for the treatment of lung cancer, among which radiotherapy is one of the most effective and least invasive for the patient. However, it has associated difficulties due to the moving target tumor. It is possible to reduce the side effects of radiotherapy by effectively tracking a tumor and reducing target irradiation margins. This paper presents a custom electromechanical system that follows the movement of a lung tumor. For this purpose, a hysteresis loop of human lung movement during breathing was studied to obtain its characteristic movement equation. The system is controlled by an Arduino, steppers motors and a customized 3D printed mechanism to follow the characteristic human breathing, obtaining an accurate trajectory. The developed device helps the verification of individualized radiation treatment plans and permits the improvement of radiotherapy quality assurance procedures.

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The Clinical Application of 3D-Printed Boluses in Superficial Tumor Radiotherapy

Frontiers in Oncology ◽

10.3389/fonc.2021.698773 ◽

2021 ◽

Vol 11 ◽

Author(s):

Xiran Wang ◽

Xuetao Wang ◽

Zhongzheng Xiang ◽

Yuanyuan Zeng ◽

Fang Liu ◽

...

Keyword(s):

3D Printing ◽

Radiation Dose ◽

Material Selection ◽

Skin Surface ◽

High Energy ◽

Clinical Applications ◽

Physical Models ◽

Target Area ◽

Air Gaps ◽

3D Printed

During the procedure of radiotherapy for superficial tumors, the key to treatment is to ensure that the skin surface receives an adequate radiation dose. However, due to the presence of the built-up effect of high-energy rays, equivalent tissue compensators (boluses) with appropriate thickness should be placed on the skin surface to increase the target radiation dose. Traditional boluses do not usually fit the skin perfectly. Wet gauze is variable in thickness day to day which results in air gaps between the skin and the bolus. These unwanted but avoidable air gaps lead to a decrease of the radiation dose in the target area and can have a poor effect on the outcome. Three-dimensional (3D) printing, a new rising technology named “additive manufacturing” (AM), could create physical models with specific shapes from digital information by using special materials. It has been favored in many fields because of its advantages, including less waste, low-cost, and individualized design. It is not an exception in the field of radiotherapy, personalized boluses made through 3D printing technology also make up for a number of shortcomings of the traditional commercial bolus. Therefore, an increasing number of researchers have tried to use 3D-printed boluses for clinical applications rather than commercial boluses. Here, we review the 3D-printed bolus’s material selection and production process, its clinical applications, and potential radioactive dermatitis. Finally, we discuss some of the challenges that still need to be addressed with the 3D-printed boluses.

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