Recent Advancement in MRI-Based Nanotheranostic Agents for Tumor Diagnosis and Therapy Integration.

Cancer remains one of the leading causes of mortality worldwide. Although conventional treatment strategies such as chemotherapy, radiotherapy, and surgery have demonstrated therapeutic potential, their clinical effectiveness is often limited by poor targeting specificity, systemic toxicity, and inadequate treatment monitoring. Magnetic resonance imaging (MRI) has emerged as a powerful diagnostic modality owing to its non-invasive nature, high spatial resolution, deep tissue penetration, and real-time imaging capabilities, making it particularly suitable for guiding and evaluating cancer therapies. Recent advances have led to the development of MRI-based nanotheranostic platforms that integrate diagnostic and therapeutic functions within a single system, enabling precise tumor imaging alongside targeted treatment. This review presents a comprehensive overview of recent progress in MRI-guided nanotheranostic agents for cancer diagnosis and therapy, with a focus on their structural design, functional mechanisms, and biomedical applications in both single treatment approaches such as photothermal therapy, photodynamic therapy, chemodynamic therapy, immunotherapy, and ferroptosis, as well as combined therapeutic strategies. In addition, the contribution of MRI to improving treatment precision through image-guided delivery, real-time therapeutic monitoring, and stimulus-responsive activation is discussed. Key challenges including biosafety, design complexity, and barriers to clinical translation are also examined, along with perspectives on future directions for developing intelligent and clinically viable MRI-integrated therapeutic systems.