Overview of Radiopharmaceutical Therapy

This talk will review the current and future state of Radiopharmaceutical therapy (RPT). RPT is a form of cancer treatment in which radioactive drugs are used to target and deliver radiation to cancer cells while minimizing radiation exposure of healthy tissue. Whether a radionuclide is appropriate for RPT depends on the half-life, the emitted particles, and the energies of those particles. However, the radionuclide must also be attached to a molecular targeting agent which causes it to be primarily deposited in cancerous rather than healthy tissue. Alpha and beta-emitting radionuclides deposit high energy at short ranges ideal for RPT, but when photons or positrons are also emitted during decay, those particles may be used to create a volumetric image. Calculating the absorbed dose to specific tissues (RPT dosimetry) using volumetric images is an active area of investigation, and must also include modeling of the biological effects of the RPT. Examples of current RPTs include 131-I for thyroid ablation, 90-Y microspheres for the treatment of liver cancer, 223-Ra for bony metastases, and 177-Lu-DOTATATE for neuroendocrine tumors. RPT has great potential to provide targeted cancer treatment which spares healthy tissue when the current challenges are better addressed.