Khashayar Nattagh1, Timmy Siauw2, Jean Pouliot2, I-Chow Hsu2, J Adam Cunha2. 1. Department of Radiation Oncology, University of California, San Francisco, CA; Department of Physics, University of California, Berkeley, CA. Electronic address: knattagh@gmail.com. 2. Department of Radiation Oncology, University of California, San Francisco, CA.
Abstract
PURPOSE: During gynecologic brachytherapy (BT), suturing and image-guided needle insertions are highly skill-dependent tasks. Medical residents often have to practice these techniques in the operating room; this is sub-optimal for many reasons. We present a fast and low-cost method of building realistic and disposable gynecologic phantoms, which can be used to train physicians new to gynecologic BT. METHODS: Phantoms comprised a rectal cavity large enough to accommodate a standard transrectal ultrasound (US) probe, a vaginal cavity, a uterus, a uterine canal, and a cervix, all embedded in a gelatin matrix. The uterus was made of gelatin and coated with rubber to mimic the texture of soft tissue and for computed tomography (CT) and US image contrast. The phantom's durability, longevity, construction times, materials costs, CT, and US image quality were recorded. The speed of sound in the gelatin was measured using pulse echo measurements. RESULTS: Anatomic structures were distinguishable using CT and US. For the first phantom, material costs were under $200, curing time was approximately 48 hours, and active participation time was 3 hours. Reusable parts allowed for reduction in time and cost for subsequent phantoms: under $20, 24 hours curing time, and 1 hour active participation time. The speed of sound in the gelatin ranged from 1495 to 1506 m/s. CONCLUSION: A method for constructing gelatin gynecologic phantoms was developed. It can be used for training in image-guided BT needle insertion, placing a suture on the vaginal wall, and suturing the cervical lip.
PURPOSE: During gynecologic brachytherapy (BT), suturing and image-guided needle insertions are highly skill-dependent tasks. Medical residents often have to practice these techniques in the operating room; this is sub-optimal for many reasons. We present a fast and low-cost method of building realistic and disposable gynecologic phantoms, which can be used to train physicians new to gynecologic BT. METHODS: Phantoms comprised a rectal cavity large enough to accommodate a standard transrectal ultrasound (US) probe, a vaginal cavity, a uterus, a uterine canal, and a cervix, all embedded in a gelatin matrix. The uterus was made of gelatin and coated with rubber to mimic the texture of soft tissue and for computed tomography (CT) and US image contrast. The phantom's durability, longevity, construction times, materials costs, CT, and US image quality were recorded. The speed of sound in the gelatin was measured using pulse echo measurements. RESULTS: Anatomic structures were distinguishable using CT and US. For the first phantom, material costs were under $200, curing time was approximately 48 hours, and active participation time was 3 hours. Reusable parts allowed for reduction in time and cost for subsequent phantoms: under $20, 24 hours curing time, and 1 hour active participation time. The speed of sound in the gelatin ranged from 1495 to 1506 m/s. CONCLUSION: A method for constructing gelatin gynecologic phantoms was developed. It can be used for training in image-guided BT needle insertion, placing a suture on the vaginal wall, and suturing the cervical lip.
Authors: Michael K Rooney; David M Rosenberg; Steve Braunstein; Adam Cunha; Antonio L Damato; Eric Ehler; Todd Pawlicki; James Robar; Ken Tatebe; Daniel W Golden Journal: J Appl Clin Med Phys Date: 2020-05-27 Impact factor: 2.102