Augmented reality for guiding biopsies in rare retroperitoneal fibrosis cases.

Retroperitoneal fibrosis (RPF) is a rare immune-mediated fibro-inflammatory disorder that often encases retroperitoneal structures, posing diagnostic and procedural challenges. Conventional image-guided biopsy techniques using CT or MRI may lead to missed lesions, sampling errors, and repeated procedures. Augmented reality (AR) platforms, such as Microsoft HoloLens-based systems, overlay 3D patient-specific anatomy in real time, enabling clinicians to visualize biopsy needle trajectories without dividing attention between monitors and the procedural field. Phantom studies have shown AR guidance can reduce soft tissue biopsy error from 1.52 to 0.75 cm, and lung lesion biopsy error from 1.12 to 0.62 cm. Despite promising accuracy gains, challenges remain in atypical RPF cases, including irregular lesion morphology, proximity to vital structures, and diagnostic ambiguity. Prospective multicenter studies are needed to confirm AR's clinical utility, assess cost-effectiveness, optimize training, and ensure practical and ethical integration into routine biopsy practice.