biostudies-literatureStockhoff MNIBIB NIH HHSNational Cancer InstituteNCI NIH HHSNational Institute of Biomedical Imaging and BioengineeringL1-L8https://www.ebi.ac.uk/biostudies/studies/S-EPMC9719735biostudies-literatureUnknown62(12)Typical PET detectors are composed of a scintillator coupled to a photodetector that detects scintillation photons produced when high energy gamma photons interact with the crystal. A critical performance factor is the collection efficiency of these scintillation photons, which can be optimized through simulation. Accurate modelling of photon interactions with crystal surfaces is essential in optical simulations, but the existing UNIFIED model in GATE is often inaccurate, especially for rough surfaces. Previously a new approach for modelling surface reflections based on measured surfaces was validated using custom Monte Carlo code. In this work, the LUT Davis model is implemented and validated in GATE and GEANT4, and is made accessible for all users in the nuclear imaging research communitPhysics in medicine and biologyAdvanced optical simulation of scintillation detectors in GATE V8.0: first implementation of a reflectance model based on measured data.PMC9719735197608R03 EB020097R35 CA197608R35 CA 197608Roncali EStockhoff MDubois ACherry SRJan SfalseAdvanced optical simulation of scintillation detectors in GATE V8.0: first implementation of a reflectance model based on measured data.Typical PET detectors are composed of a scintillator coupled to a photodetector that detects scintillation photons produced when high energy gamma photons interact with the crystal. A critical performance factor is the collection efficiency of these scintillation photons, which can be optimized through simulation. Accurate modelling of photon interactions with crystal surfaces is essential in optical simulations, but the existing UNIFIED model in GATE is often inaccurate, especially for rough surfaces. Previously a new approach for modelling surface reflections based on measured surfaces was validated using custom Monte Carlo code. In this work, the LUT Davis model is implemented and validated in GATE and GEANT4, and is made accessible for all users in the nuclear imaging research communit2017-01-01T00:00:00Z2017 Jun2025-04-19T04:42:17.357Z2025-04-19T04:42:17.357ZS-EPMC97197352845233910.1088/1361-6560/aa7007