First Clinical Evaluation of Nanophotonic Scintillators for Radiation Dosimetry
Abstract
Purpose
Recent advances in nanophotonic engineering have enabled subwavelength nanostructures to be patterned onto conventional scintillating materials, significantly enhancing light yield by both amplifying and directing emission toward the detector. This study represents the first clinical evaluation of nanophotonic scintillators for radiation dosimetry.
Methods
A YAG:Ce scintillator with surface-patterned nanophotonic structures was coupled to a CMOS camera within a 3D-printed light-tight enclosure. Dose linearity was evaluated across 6, 10, and 15 MV photons and 6, 9, 12, 16, and 20 MeV electrons. Gafchromic film served as the reference standard for absolute dose calibration. Dose rate dependence was characterized up to 2400 Monitor Unit/min to assess suitability for ultra-high dose rate (UHDR) monitoring. Contrast-to-noise ratio (CNR) was quantified and benchmarked against conventional scintillators. Finally, the system was validated in a clinical total body irradiation (TBI) setup using an anthropomorphic phantom.
Results
The nanophotonic scintillator demonstrated 6-fold enhancement in light yield and 4-fold improvement in CNR compared to conventional YAG:Ce scintillators. Dose-response linearity was excellent (R² > 0.99) across all electron and photon energies tested. Scintillation signal was independent of dose rate up to 2400 MU/minute, indicating its potential for UHDR monitoring. In the TBI setup under ambient room lighting, the nanophotonic scintillator produced signal detectable (SNR>4) with the CMOS camera as well as consumer smartphone camera, whereas conventional scintillators generated no measurable signal under identical conditions, demonstrating potential for robust real-time dosimetry under ambient room lighting, circumventing the requirement for expensive time-gated acquisition.
Conclusion
This work provides the first clinical characterization of nanophotonic scintillators for medical physics applications. The technology exhibits substantial light enhancement while maintaining dose rate independence and linearity, demonstrating promises for both UHDR applications (FLASH radiotherapy) and low dose rate conditions (TBI), as well as applications in reducing doses in kV imaging.