Prostate cancer is the second most common cancer in men. Diagnosing it, however, can be more difficult than its frequency might suggest. “When a patient presents with suspicion of cancer, such as a high PSA (prostate-specific antigen) level and a positive digital rectal examination, a prostate biopsy may be requested,” said Samsun (Sem) Lampotang, Ph.D., professor of anesthesiology and urology. Sampling prostate cancer via biopsy can be a challenging procedure that relies on a practitioner’s skill and training. As director of the Center for Safety, Simulation & Advanced Learning Technologies (CSSALT), Lampotang recently contributed to the creation of a new mixed-reality simulator that helps train practitioners’ accuracy in performing prostate biopsies.
Systematic prostate biopsies involve taking a number (e.g., 12) of small tissue samples called cores and evenly distributing them in the prostate gland. If the cores are unevenly distributed, some areas of the prostate may not be sampled. “To diagnose the cancer during the pathology exam, the biopsy needle needs to sample the cancer,” said Lampotang. A false negative will occur if prostate cancer is present in regions that are not sampled. Studies report false negative rates of up to 47%.
To address this gap, a new mixed-reality prostate biopsy simulator has been developed to improve procedural accuracy. The simulator enables practitioners to practice and improve their accuracy with freehand systematic prostate biopsies. The simulator was designed, built, and validated by CSSALT. Its efficacy has been documented in the paper “Development and Validation of a Mixed-Reality Simulator for Reducing Biopsy Core Deviation During Simulated Freehand Systematic Prostate Biopsy,” recently published ahead of print in Simulation in Healthcare.
Lampotang’s interest in improving the procedural accuracy of prostate biopsies began nearly a decade ago. “Nine or ten years ago I was talking with Li-Ming Su, the chair of the Department of Urology, and he mentioned a Johns Hopkins paper that indicated uneven biopsy core distribution in a sample of five experienced practitioners. That uneven core distribution was unexpected. This simulator helps to train users how to perform prostate biopsies accurately by providing an opportunity to practice, a 3D perspective visualization of the procedure, and immediate graphical and numerical feedback on accuracy in core placement.”
The team developed a mixed-reality simulator that combines physical and virtual elements: a modular block with simulated anatomy, electromagnetically tracked transrectal ultrasound (TRUS) probe and biopsy needle that trainees can hold and steer, a 3D perspective display that acts as training wheels to help novice trainees visualize and guide the TRUS probe and biopsy needle, and audio prompts related to potential patient discomfort. CSSALT’s System of Modular, Mixed, and Augmented Reality Tracking Simulators (SMMARTS) software development kit was used in construction of the simulator.
To evaluate the simulator’s efficacy, researchers conducted a study involving urologists with varying levels of expertise. Participants performed freehand systematic prostate biopsies on the mixed-reality simulator. The study measured the deviation of each biopsy core from its intended location. The results demonstrated a significant reduction in core deviation when comparing before and after training, indicating that distribution of cores was more even after training. The participants also reported high levels of satisfaction with the training experience and found the 3D visualization helpful for accurate core placement. This new training tool improves the accuracy of systematic prostate biopsies, potentially leading to improved prostate cancer diagnoses and treatment outcomes for patients.