Theragnosis is a patient management strategy involving the integration of diagnosis and therapy. In oncology, theragnosis combines the fields of tumour diagnosis and therapy in an attempt to improve upon existing techniques. The possibilities of identifying the disease, orienting treatment and conducting follow-up open up a new chapter in precision medicine.

In molecular nuclear medicine, theragnosis refers to the use of molecules labeled with radionuclides (positron or gamma radiation emitters) for diagnostic purposes, or molecules

labeled with therapeutic radionuclides (beta particle emitters) for the diagnosis and treatment of a given disease. Thus, molecular imaging and diagnosis of the disease can lead effectively to personalized treatment using the same study molecules.

One of the most common examples of theragnosis in nuclear medicine is the use of gallium 68 as a diagnostic tracer, followed by therapy with radionuclides such as lutetium 177 to label the same molecule in the context of personalized therapy.