Theranostics in Cancer: Integration of Diagnosis and Therapy

Theranostics represents a transformative integration of two approaches, i.e., diagnostic and therapeutic, in modern oncology healthcare and a patient-centric framework. The modern theranostic approach enables real-time visualization of the tumor, therapeutic planning and response, and accurate stratification of patients’ dosimetry. Thereby, mitigating the limitations of “one-size-fits-all” for all conventional cancer therapeutics. This chapter reconnoitres the etymological and linguistic evolution alongside molecular components and principles and clinical translation with emphasis on radiotheranostics in cancer healthcare management. It also highlights the fundamental components (radionuclide, ligand, chelator, linker, and molecular target) and governing principles of radiotheranostics along with their possible mechanisms of action, such as ROS generation, cell cycle arrest, DNA damage, activation of antitumor immune response, induced apoptosis, and autophagic mechanisms of cell death. Clinically validated theranostic platforms targeting somatostatin receptors in neuroendocrine tumors and prostate-specific antigen in prostate cancer (PC) are also explored in this chapter, highlighting their emerging role in targeting molecular targets, such as HER2, CXCR4, CD20, and fibroblast activation protein. This chapter also explores the emerging and advancing role of nano-theranostics in sustained drug delivery with minimal toxicity to healthy cells. However, theranostic platforms often face challenges, such as tumor heterogeneity, toxicity, cost, safety, and regulatory concerns. Overcoming these limitations can make the theranostic platform a cornerstone of precision medicine and therapy.