A High-Fidelity Agar-Based Phantom for Ultrasonography-Guided Brain Biopsy Simulation: A Novel Training Prototype with Visual Feedback

A novel agar-based phantom was developed and assessed for ultrasonography (USG)-guided brain biopsy training. The phantom provides visual cues combined with sonologic cues, allowing multimodal training. Impact of multimodal training is evaluated through pretraining and posttraining trials.

Twenty-five participants were divided based on experience with USG-based procedures into familiar (≥3 procedures performed in the past) (n = 14) and unfamiliar (<3 procedures performed) (n = 11). Agar phantoms with an opaque top and transparent middle layer were constructed in transparent glass bowls, each having 12 embedded targets. Participants underwent 2 supervised trials of USG-guided biopsy with aluminum foil covering the glass bowls, eliminating visual cues. Between 2 trials, participants underwent unsupervised self-training on a phantom without foil cover, providing visual cues. Performance was measured through insonation efficiency (EfI), biopsy efficiency (EfB), efficiency score (Ef), error score (Er), and performance score (PS). Scores were compared between and within the 2 groups before and after training. Impact of the self-training session on subjective comfort levels with the procedure was assessed through feedback forms.

Familiars had better pretraining EfB, Ef, Er, and PS (P < 0.001) compared with unfamiliars. After training, both performed similarly on all metrics. After training, familiars improved only in EfI (P = 0.001), with the unfamiliars showing significance in all metrics except EfI.

Simulation and phantom-based models can never supplant training through supervised skill application in vivo but our model supplements training by enabling technical skill acquisition, especially for beginners in USG-guided brain biopsy.