Radiolabeled exosomes for theranostics: Personalized tailored therapy through imaging

Radiolabeled exosomes have emerged as a transformative platform at the intersection of nanomedicine, molecular imaging, and precision theranostics. These nanoscale extracellular vesicles exhibit intrinsic biocompatibility, low immunogenicity, and inherent targeting capabilities, making them highly attractive for both diagnostic and therapeutic applications. The integration of radiochemistry with exosome biology enables noninvasive, real-time tracking of biodistribution, pharmacokinetics, and target engagement using advanced imaging modalities such as positron emission tomography and single-photon emission computed tomography. This minireview comprehensively summarizes current radiolabeling strategies for exosomes, including direct and indirect approaches, highlighting their advantages, limitations, and impact on vesicle integrity and imaging accuracy. Furthermore, we discuss key imaging platforms, in vivo biodistribution patterns, and pharmacokinetic profiles that influence therapeutic efficacy. Critical challenges such as rapid clearance by the mononuclear phagocyte system, labeling instability, and the lack of standardized protocols are also addressed. Finally, we outline future perspectives focusing on advanced bioengineering, multimodal imaging integration, and clinical translation frameworks. Radiolabeled exosomes represent a promising next-generation theranostic system with the potential to enable personalized, image-guided therapies across oncology and regenerative medicine.