Development of An Original Multi-Modality Gynecologic Brachytherapy Phantom
B Eckroate1*, J Raffi2, R Venkataraman3, Y Kim4, D Ayala-peacock5, O Craciunescu6, (1) Duke University, Durham, NC, (2) Duke University Medical Center, Durham, NC, (3) Eigen Health Services Llc, Grass Valley, CA, (4) Duke University Medical Center, Durham, NC, (5) Duke University Medical Center, Durham, NC, (6) Duke University Medical Center, Durham, NC
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PO-GePV-T-26 (Sunday, 7/10/2022) [Eastern Time (GMT-4)]
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Purpose: To develop a realistic female pelvic phantom using 3D printing and molding techniques that can be imaged with MRI, CT, and transrectal ultrasound (TRUS) and intended for clinical training of needle insertion in TRUS-guided gynecologic interstitial brachytherapy.
Methods: The pelvic phantom was designed using 3D Slicer and Autodesk Fusion360 to model female anatomy collected from a patient data study1. A vaginal canal and rectum were modeled from the physical dimensions of a KleenSpec speculum and BK8848 US probe, respectively. Anatomy was Boolean subtracted from solids to create a negative space mold. A Stratasys J750 was used to print cost-effective 3D molds to cast anatomy. Smooth-On Silicone 20T, which has mechanical properties similar to female pelvic anatomy, was selected as a casting material for the vaginal canal, cervix, uterus, and rectum wall. The designed anatomy was housed in a 3D printed box designed to allow for speculum, applicator, needle, and US probe insertion. Gelatin and agar formulations were tested as tissue-equivalent media to support anatomy and for ultrasound propagation. The imaging systems used were a BK FlexFocus ultrasound system with BK8848 probe at 6MHz, Siemens Biograph mCT with a slice thickness of 1mm, and a Siemens Skyra 3T MRI with a slice thickness of 2mm, following clinical imaging protocols for gynecological HDR brachytherapy patients.
Results: The MRI, CT and US images show the pelvic anatomy and inserted needle. Compared to gelatin, the agar formulation can be adjusted to be stiffer to maintain structural integrity during needle insertion.
Conclusion: An initial prototype of a multi-modality phantom for TRUS-guided gynecologic HDR applications was constructed. Further improvements are needed for better visualization of applicators within the silicone anatomy. This pelvic phantom will be used to investigate needle tracking capabilities of a motorized ultrasound stepper. 1. Campelo, et al. (2020). Brachytherapy, 19(6), 767–776
Keywords
Taxonomy
TH- Brachytherapy: Development (new technology and techniques)
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