However, because of the short path length travelled, the alpha particle needs to be delivered into or right next to the tumor cell. An advantage of the short path length is that only the cells in close proximity to the alpha particle are destroyed, sparing other healthy and normal tissues. The amount of energy is high enough so that only a small number (1-10) of alpha particles lead to lethal damage to cells. Alpha particles have the advantage of a very high amount of energy and a short path length.

In terms of attaching the radioactive isotopes, we can use both alpha and beta particles depending on the location and size of the tumor. We have engineered very specific monoclonal antibodies and molecules that will bind only to PSMA, leading to the opportunity for “molecularly targeted” (radio-)therapy. This lock sits on the surface of each prostate cancer cell. This is similar to a “lock and key” scenario, where the antibody or molecule resembles the key that will only recognize a very specific lock (the cancer-related molecule).Īs it turns out, essentially all prostate cancer cells have a specific “lock” called prostate-specific membrane antigen (PSMA). Radioimmunotherapy or radioligand therapy involves the practice of attaching a radioactive isotope to a cancer-targeting antibody or small molecule that binds only to a specific cancer-related molecule on a tumor cell. This generally occurs near tumor cells, and while we don’t know the exact mechanism of action, we suspect that in addition to being in close proximity to some tumor cells, this creates a less hospitable environment for the tumor cells that have spread to the bone.Īdditionally, we can now utilize different targeting agents to take radionuclides directly to the tumor cells. Radium-223 is an alpha particle that mimics calcium and is delivered and taken up by the bone cells. However, unlike the previous beta-emitting agents, radium-223 was FDA-approved because it leads to longer overall survival rather than just symptom relief. More recently, the alpha-emitting agent radium-223 (Xofigo) was approved for men with metastatic castration-resistant disease that has spread to the bone. For example, Strontium-89 (Metastron) and samarium-153 (Quadramet) are beta-emitters that are taken up like calcium into bone and were approved to decrease pain. Historically, bone-seeking radioisotopes were used for patients with painful tumors in the bone. Several radioisotopes – using both alpha and beta particles - have been approved by the Food and Drug Administration (FDA) for clinical use in cancer treatment. The two main categories of radiation particles used to kill cancer cells are alpha and beta particles.

This is a good thing when we’re using radiation as a way to kill cancer cells. The different particles they emit vary and some types emit damaging radiation (also called ionizing particles). Radionuclides, also known as radioisotopes, are particles that emit energy. Ukraintsev, Reactivity Effects in Power Reactors (Obninsk.

Plyaskin, Radiative Neutron Capture, Reference Book (Energoatomizdat, Moscow, 1986). Rubtsov, et al., Handbook of Beta and Antineutrino Radiation from Radioactive Nuclei (Energoatomizdat, Moscow, 1989).

Beta particles