Preliminary study of the dosimetric characteristics of 3D-printed materials with megavoltage photons

Jeong, Seonghoon; Yoon, Myonggeun; Chung, Weon Kuu; Kim, Dong Wook

doi:10.3938/jkps.67.189

Cited by 7 publications

(3 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The pancreas and duodenal structures of the phantom were filled with radiochromic FXG (Fricke xylenol orange) gel (Lee et al 2018). This combination of filament and gel was chosen due to their tissueequivalent and radiological properties (Keall and Baldock 1999, Ehler et al 2014, Burleson et al 2015, Jeong et al 2015, Craft and Howell 2017, Craft et al 2018. An air-filled cavity within the duodenum was incorporated in the phantom design to induce the electron return effect at the duodenal wall during irradiation on a prototype Elekta MR-Linac (Elekta Instruments AB, Stockholm, Sweden) with orthogonal magnetic and irradiation fields.…”

Section: Phantom Targetmentioning

confidence: 99%

Simultaneous motion monitoring and truth-in-delivery analysis imaging framework for MR-guided radiotherapy

Mickevicius¹,

Chen²,

Boyd³

et al. 2018

Phys. Med. Biol.

View full text Add to dashboard Cite

Intrafraction motion (i.e., motion occurring during a treatment session) can play a pivotal role in the success of abdominal and thoracic radiation therapy. Hybrid magnetic resonance-guided radiotherapy systems have the potential to control for intrafraction motion. Recently, we introduced an MRI sequence capable of acquiring real-time cine imaging in two orthogonal planes (SOPI). We extend SOPI here to permit dynamic updating of slice positions in one plane while keeping the other plane position fixed. In this implementation, cine images from the static plane are used for motion monitoring and as image navigators to sort stepped images in the other plane, producing dynamic 4D image volumes for use in dose reconstruction. A custom 3D-printed target, designed to mimic the pancreas and duodenum and filled with radiochromic FXG gel, was interfaced to the dynamic motion phantom. 4D-SOPI was acquired in a dynamic motion phantom driven by an actual patient respiratory waveform displaying amplitude/frequency variations and drifting and in a healthy volunteer. Unique 4D-MRI epochs were reconstructed from a time series of phantom motion. Dose from a static 4cmx15cm field was calculated on each 4D respiratory phase bin and epoch image, scaled by the time spent in each bin, and then rigidly accumulated. The phantom was then positioned on an Elekta MR Linac and irradiated while moving. Following irradiation, actual dose deposited to the FXG gel was determined by applying a R1 versus dose calibration curve to R1 maps of the phantom. The 4D-SOPI cine images produced a respiratory motion navigator that was highly correlated with the actual phantom motion (CC=0.9981). The mean difference between the accumulated and measured dose inside the target was 4.4% of the maximum prescribed dose. These results provide early validation that 4D-SOPI simultaneously enables real-time motion monitoring and truth-in-delivery analysis for integrated MRguided radiation therapy (MR-gRT) systems.

show abstract

Section: Phantom Targetmentioning

confidence: 99%

Simultaneous motion monitoring and truth-in-delivery analysis imaging framework for MR-guided radiotherapy

Mickevicius¹,

Chen²,

Boyd³

et al. 2018

Phys. Med. Biol.

View full text Add to dashboard Cite

show abstract

“…Commonly used dose evaluations for AM-RDPs involve percentage depth dose evaluation and measurements of dose distributions through thermoluminiscent dosimeters, 61,62 ionization chambers, 63,64 and film dosimetry. [65][66][67][68][69] More recently, studies also utilize motor actuators 67,70 and readily available motion platforms 40 in combination with the printed imaging and dosimetry phantoms to evaluate tumor tracking (fiducials).…”

Section: Manufacture Of Am-rdpsmentioning

confidence: 99%

A Systematic Review on 3D-Printed Imaging and Dosimetry Phantoms in Radiation Therapy

Tino

Yeo

Leary

et al. 2019

Technol Cancer Res Treat

112

View full text Add to dashboard Cite

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.

show abstract

“…Thermoplastic polyurethane (TPU) was used as our printing material of choice.It offers improved flexibility compared to the rigid materials described in previous studies. [10][11][12][13][14][15] The resultant bolus is bespoke to the patient's surface anatomy offering the potential for improved conformality, comfort and ease of placement throughout the patient's treatment, compared to traditional bolus approaches. However, to our knowledge only individual case studies or studies with small sample sizes that assess the benefit of using 3D printed bolus have been presented.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of the quality of fit of flexible bolus material created using 3D printing technology

Malone¹,

Gill²,

Lott³

et al. 2022

J Applied Clin Med Phys

View full text Add to dashboard Cite

Aims To retrospectively evaluate the quality of fit of 3D printed bolus over four different treatment sites to determine whether certain sites favor a 3D printed approach and if the quality of fit changes over the course of treatment. Materials and methods A retrospective analysis of the first 60 cases treated using 3D printed bolus in our radiotherapy center was undertaken. All boluses were printed using flexible thermoplastic polyurethane (TPU) material. We developed a system of rating the quality of fit using four quality categories. The analysis of 60 patients consisted of a review of a total 627 treatment fractions for head and neck (H&N), scalp, pelvis, and extremity treatment sites. Results Out of 627 fractions evaluated, 75.1% were rated either “good” or “excellent”, 20.6% were rated as “acceptable” and 4.3% were rated “poor”. H&N, scalp, and extremity treatment regions were found to favor a 3D printed approach. However, pelvis cases had a higher proportion of “acceptable” and “poor” ratings. Trend analysis showed no notable change in the quality of 3D printed bolus fit over the course of treatment, except for pelvis cases which tended to change categories more than other treatment sites. Conclusion This evaluation demonstrates that 3D printed bolus, created using semi‐flexible materials such as TPU, is an effective and practical bolus choice for radiotherapy. In particular, using a 3D printed approach for H&N, scalp, and extremities was found to have a highly conformal fit.

show abstract

Preliminary study of the dosimetric characteristics of 3D-printed materials with megavoltage photons

Cited by 7 publications

References 18 publications

Simultaneous motion monitoring and truth-in-delivery analysis imaging framework for MR-guided radiotherapy

Simultaneous motion monitoring and truth-in-delivery analysis imaging framework for MR-guided radiotherapy

A Systematic Review on 3D-Printed Imaging and Dosimetry Phantoms in Radiation Therapy

Evaluation of the quality of fit of flexible bolus material created using 3D printing technology

Contact Info

Product

Resources

About