Room: AAPM ePoster Library
To design and manufacture a cost effective gynecologic phantom to support training opportunities to improve procedure proficiency in ultrasound-guided interstitial gynecologic brachytherapy.
Two materials were tested and evaluated for material selection for gynecologic phantom fabrication, Ecoflex 00-30 silicone (Smooth-on, PA), and PVC (M-F Manufacturing Co., TX). The phantom was designed in Autodesk Inventor, and comprised of a simulated rectum, vagina, cervix, uterus, bladder, and surrounding tissue. Each component was cast in 3D printed molds using an EVO22 3D printer (Airwolf 3D, CA) with acrylonitrile-butadiene-styrene (ABS) filament. The phantom's durability, longevity, fabrication time, material cost, and ultrasound image quality were determined. The ultrasound-guided gynecologic interstitial brachytherapy simulation study was implemented using a BK 3000 ultrasound system with an E14CL4b transrectal probe for the phantom imaging evaluation.
The speed of sound was measured using pulse echo measurements for silicone and PVC. PVC was found to be most similar to soft tissue in ultrasound characteristics with 1415.0 m/s speed of sound compared to 1540 m/s for soft tissue. The final phantom design was 20x20x10 cm³ using PVC. Anatomic structures were distinguishable on ultrasound images. The rectum, vaginal wall, and uterus were identified as hyperechoic while the water filled bladder was hypoechoic. The thickness of rectum and vaginal walls were measured at 11 and 12.2 mm, respectively. A complete phantom may be fabricated in 2 to 3 hours with material cost for each phantom estimated at $102. Reusable casting accessories are approximated at $108.
A novel low-cost ultrasound-based gynecologic phantom was developed by casting PVC into 3D-printed molds. The proposed educational gynecologic phantom is an ideal, cost-effective platform for building confidence in fundamental interstitial brachytherapy procedural skills as a supplement patient caseloads.