Theranostics

Theranostics is a medical approach that combines therapy and diagnostics within a single framework to tailor treatment to individual patients. In practice, theranostics relies on molecular targets that can be visualized and then attacked with targeted therapy, often using radiopharmaceuticals that enable both imaging and treatment.

In nuclear medicine, theranostics relies on paired diagnostic and therapeutic agents that share the same molecular target. Examples include neuroendocrine tumors treated with a diagnostic Ga-68 DOTATATE PET scan and a therapeutic Lu-177 DOTATATE, and prostate cancer where Ga-68-PSMA-11 PET imaging guides the use of Lu-177-PSMA-617 therapy. Thyroid cancers historically illustrate the concept with diagnostic scans using I-123 or I-131 and therapeutic I-131. Dosimetry and serial imaging help select patients, determine dosing, and monitor response.

Beyond radiopharmaceuticals, theranostics also encompasses non-radioactive approaches, including targeted drug delivery and image-guided therapies. Nanoparticles and antibody-drug conjugates are explored to provide simultaneous diagnostic signals and therapeutic action, an area often referred to as nanotheranostics.

Theranostics aims to improve patient outcomes by selecting appropriate therapies, sparing nonresponders, and enabling real-time monitoring of treatment effects. While widely used in oncology, the field is expanding to other diseases and involves ongoing challenges such as regulatory pathways, cost, standardization of procedures, and the need for robust clinical evidence.