放射性標識ビタミンおよびナノシステムのがん治療診断薬としての可能性：開発アプローチと将来展望

Theranostic approaches employing radioactive materials have emerged as innovative strategies that integrate molecular imaging with targeted therapy using nanosystems, thereby advancing the paradigm of precision medicine in oncology. Each year, substantial research efforts are dedicated to developing molecular probes capable of detecting early-stage tumors, with improved efficacy and reduced toxicity to the surrounding healthy tissues. Radiopharmaceuticals based on vitamins and nanoparticles are among the most promising developments in this field, as they possess a high level of specificity and low toxicity. Vitamin B9 and vitamin B12 represent notable examples, as their targeting properties exploit the overexpression of corresponding receptors in tumor cells. In this context, future directions may include the radiolabeling of nanoparticles functionalized with these vitamins using isotopes such as [⁶⁸Ga] and [¹⁷⁷Lu], thereby enabling both diagnostic imaging and therapeutic applications. Despite the encouraging preclinical evidence, many in vitro and in vivo studies employing these strategies do not sufficiently address their translational applicability to radiotheranostics. This review highlights the most promising advances in the diagnostic and therapeutic potential of vitamin and nanoparticle-based systems. It aims to critically evaluate current findings and propose hypotheses for further study in the emerging field of radiopharmaceutical theranostics.