3D-Printed Phantom to Simulate Ultrasound-Guided High-Dose-Rate (HDR) Interstitial Prostate Brachytherapy for the Training of Medical Physics Residents
Abstract
Purpose
Ultrasound-guided high-dose-rate (HDR) interstitial prostate brachytherapy is a technically demanding procedure requiring proficiency in imaging, catheter reconstruction, contouring, treatment planning, and quality assurance under time-constrained conditions. Training opportunities for deliberate practice are limited because instruction is typically tied to live clinical cases, where patient safety, workflow constraints, and the need to minimize procedure time restrict repetition of key skills. This work developed and implemented a low-cost prostate phantom to support realistic ultrasound-based HDR prostate brachytherapy training of medical physics residents outside the stressful clinical environment.
Methods
A modular phantom system was designed using accessible fabrication methods, including 3D-printing and inexpensive, widely available materials. The system consists of a water-sealed external housing with a gridded cradle, a silicone-encased gelatin prostate model, and an embedded Foley catheter to simulate the urethra and bladder. The phantom is compatible with standard clinical hardware (e.g., ultrasound stepper, template, and commercial treatment planning system). Needle insertion, imaging, contouring, and treatment planning workflows were performed using the phantom to evaluate its realism, consistency, and suitability for hands-on training.
Results
Ultrasound imaging demonstrated clear visualization of prostate boundaries, urethral structures, and needle positions in both axial and sagittal planes. Needle insertion, reconstruction, contouring, and treatment planning closely mirrored clinical workflows. The phantom supported repeated practice for medical physics residents of key procedural and planning tasks in a non-clinical environment, enabling deliberate skills development without reliance on live patient cases.
Conclusion
This low-cost prostate phantom provides a practical educational platform for ultrasound-guided HDR interstitial prostate brachytherapy training outside time-constrained clinical settings. By enabling realistic, repeatable practice using standard clinical equipment and workflows, the model supports proficiency development while reducing barriers associated with operating room–based training. The simplicity, affordability, and compatibility of the design facilitate adoption by other residency training programs and clinics, including those in resource-limited environments.