A Primer on Radiopharmaceutical Therapy Radiobiology
Description
Radiopharmaceutical therapy (RPT) is re-shaping how radiation is used to combat cancer since it provides a way to deliver radiation systemically. Due to its impactful clinical applications, RPT has been approved by the FDA to treat patients with metastatic castration-resistant prostate cancer and gastroenteropancreactic neuroendocrine tumors. Dozens of RTP clinical trials are underway for several types of cancer. RPT relies on an initially nonradioactive precursor (e.g., synthetic molecules, antibodies, nanoparticles) labeled with a radionuclide to molecularly target radiation to cancer cells. Electrons from beta (β) particle decay, internal conversion (IC) or Auger effect (AE), or alpha (α) particles from α decay are the main radiation types used in RPT. Due to the different physical properties of RPT radioisotopes, they induce different types of cellular damages. These damages are also dependent on the spatial distribution of the radioisotope within the tissue (cancer or normal) for β emitters or even within the cell for IC, AE and α emitters. These contrasting differences on the physical properties among RPT emitters have different biological consequences. This symposium will discuss basic and clinical radiobiology of radioisotopes used in RPT, how they can be compared with external beam RT and gaps in our understanding of RPT radiobiology that need to be addressed to maximize the clinical potential of RPT, all in the context of recent FDA approved RPT agents and ongoing clinical trials.