Theranostics 2.0: The Expanding Clinical Applications of Radioligand Therapy Beyond Oncology—A Narrative Review

Theranostics, the convergence of molecular imaging and targeted therapy, has revolutionized cancer care and is now expanding into nononcologic domains. Increasing evidence supports its clinical potential in cardiovascular, inflammatory, and neurological diseases. This review explores emerging theranostic strategies in conditions such as atherosclerosis, rheumatoid arthritis (RA), cardiac amyloidosis, myocardial inflammation, Alzheimer’s disease (AD), and multiple sclerosis. Key advancements include radioligands such as ⁶8Ga-DOTATATE for vascular inflammation, ⁹9mTc-labeled anti-TNF agents for autoimmune arthritis, and ¹8F-florbetapir for cardiac amyloid imaging. Nanotechnology-based delivery systems are enhancing precision, enabling selective drug targeting, and improving imaging contrast, particularly in autoimmune and neurodegenerative conditions. The integration of artificial intelligence further refines image analysis and dosimetry, paving the way for personalized interventions. However, several challenges remain, including limited radionuclide access, regulatory complexities, and the difficulty of crossing the blood–brain barrier. Despite these hurdles, ongoing clinical trials and translational research underscore the growing viability of theranostics beyond oncology. Continued interdisciplinary collaboration, technological innovation, and standardized validation protocols will be crucial for transforming these targeted approaches into routine care for complex chronic diseases.