Position-tracked handheld optical coherence tomography guided by projected wide-field near-infrared autofluorescence imaging for breast tumor margin assessment.

Breast tumor margin assessment requires rapid identification of regions of interest (ROIs) and detailed visualization of their microstructural alterations. Here, we report position-tracked handheld optical coherence tomography (PH-OCT) guided by projected wide-field near-infrared autofluorescence (PW-NIRAF) imaging to meet these requirements. The PW-NIRAF system comprises a near-infrared (NIR) imaging camera and a projector with calibrated fields of view, enabling ROI identification and projection of the corresponding ROI map over a 10 × 10 cm2 field of view (FOV). The PH-OCT system consists of a handheld gradient-index-rod-lens-based OCT probe for volumetric visualization of ROI microstructure, with each OCT volume covering 4 × 4 × 1 mm3 at 9.66 μm axial and 17.54 μm lateral resolution. Blue and green tapes used as color markers on the OCT-probe housing, together with a color camera and a deep-learning-based YOLOv11-pose model, enable real-time probe-tip localization for OCT volume acquisition across PW-NIRAF-projected ROIs, providing depth-resolved microstructural information beyond wide-field NIRAF contrast. Color-camera/projector calibration further enables back-projection of OCT-derived tumor-region maps onto the tissue surface. Validation on ex vivo breast tissue lays the foundation for future intraoperative breast tumor margin assessment using PW-NIRAF-guided PH-OCT.