June 4, 2015
There has been growing discussion and excitement surrounding the possibility of personalized medicine and targeted radionuclide therapy (TRT) in recent years.1 TRT refers to the use of one or more radionuclides that may be incorporated into a conjugate or attached to a ligand for targeted therapy at the cellular or molecular level. Radioimmunotherapy refers to targeted therapy with a radiolabeled monoclonal antibody. TRT has actually been part of routine medical therapy for several years.
Indeed, physicians have been imaging and treating patients with thyroid disease using radioactive iodine since 1946.2 The first use of iodine-131 (I-131) radioimmunotherapy occurred in 1982.3 Theranostics is a process of therapy for individual patients where treatment can be tailored based on imaging results using the same molecule and targets on tumor cells. Using the same or similar radiopharmaceutical for both imaging and therapy provides the opportunity to image disease sites that will be targeted both before and after therapy. It also provides the possibility of seeing what will be treated, estimating the amount of radioactivity that will be taken up at sites of disease versus the amount that will be taken up by normal tissue and calculating the specific amount of radioactivity needed to achieve maximum efficacy with limited toxicity.