Principles of Molecular Targeting for Radionuclide Therapy

Abstract

Molecular targeting requires assessing several factors that come into play such as the location of the target, the choice of radionuclide, the inertness of the bifunctional chelate and stability of the covalently bound halogens, matching the residence time in the tumor with the physical half-life of the radionuclide, the scale and scope of the disease, and the absorbed dose sensitivity of the targeted tumor compared to normal tissue. The principles of molecular targeting are well established, but a paradigm shift from designing a medium-affinity radiotracer used to determine target density to designing a high-affinity, high-target density radioligand to maximize the target-to-nontarget ratio should increase the probability of detecting lesions smaller than the instrument resolution.Developing and validating a therapeutic radiopharmaceutical for a single target is Keywords Alpha particles • Beta particles • Auger electrons • Molecular targeting • Therapeutic radionuclides • Theranostics • Double-strand breaks • Bystander effects • Residence time W.C. Eckelman (*) Molecular Tracer,

Radiolabeling of Theranostic Nanosystems

“…Subpar effects will be seen in a small tumor treated with long-range (low LET) irradiation (A) or in a large mass treated with a short-range (high LET) irradiation with heterogenous distribution (B), whereas optimal results are achieved when a relatively homogenous distribution of an intermediate LET radioisotope is attained (C). Figure adapted from reference [2].…”