Radioluminescence microscopy of tumor organoids enabled by a reconfigurable high-resolution imaging setup

Background: This study aims to construct and implement an experimental radioluminescence microscopy (RLM) setup using a standard light microscope to visualize tumor organoids with high resolution. This approach seeks to address the challenges of imaging organoids, facilitating advancements in precision medicine for cancer research. Tumor organoids grown in collagen were incubated with 100 MBq to 120 MBq of 18F-fluorodeoxyglucose to visualize metabolic activity within their structures. Imaging was performed using a sensitive electron-multiplying charge-coupled device in conjunction with a scintillator crystal and an optical system with a high light collection efficiency and adapted magnification. Results: The constructed RLM setup demonstrated high-resolution imaging of organoid samples, significantly exceeding the resolution achievable with positron-emission tomography. The combination of RLM with brightfield and fluorescence microscopy provided comprehensive morphologic and metabolic characterization of the organoids at sub-organoid spatial resolution. Conclusion: The study successfully illustrates the feasibility of using a modified light microscope for RLM to achieve imaging of tumor cell metabolism in organoids with a spatial resolution on the order of tens of micrometers. This approach opens new avenues for studies of tumor cell metabolism during tumor progression and during therapeutic interventions.