Sharpening the surgeon’s eye: an adaptable dual-mode gamma probe architecture optimized for high-resolution and high-sensitivity radio-guided surgery

Abstract Objective. To design and validate a single, reconfigurable gamma probe that overcomes the static compromise between spatial resolution and sensitivity in radio-guided surgery, enabling both rapid lesion detection and precise margin delineation. Approach. A dual-layer lead collimator was designed for a LaBr₃(Ce)-SiPM detector. A validated analytical model coupled with a multi-objective genetic algorithm (NSGA-II) was used to explore the theoretical performance limits and identify optimal geometries. A two-phase computational search identified a single, universal geometry that can be switched intraoperatively between a high-sensitivity (HS) mode and a high-resolution (HR) mode by adjusting collimator positions. Main results. The universal design, at a 30 mm distance, achieves a spatial resolution of 6.41 mm full width at half maximum (FWHM) in HR mode and a sensitivity of 1483 counts per second (cps)/MBq in HS mode. The optimization framework identified specialized, distance-specific theoretical designs with resolutions as fine as 3.26 mm FWHM. The underlying detector’s energy resolution is sufficient to distinguish between ⁹⁹ m Tc (140.5 keV) and 123 I (159 keV). Significance. This work presents a practical, single-instrument solution that offers surgeons the intraoperative flexibility to prioritize either rapid detection or precise delineation. The developed design methodology provides a robust framework for creating next-generation, application-specific surgical guidance tools.