THERANOSTICS DICTIONARY

ALPHA RADIATION: are radioactive particles that are very heavy so alpha particles can only travel a very short distance and they are unable to penetrate most matter. Alpha radiation can’t travel through skin or even a piece of paper. Alpha particles do however emit a high amount of radiation. It only takes 2-10 hits from an alpha particle to damage DNA. Alpha radiation can be used to treat cancers.

ATOMS: the basic building block of all matter. It consists of a nucleus that contains neutrons and protons. The atoms are surrounded by electrons in orbit.

BECQUERELS: a measure of quantity of radioactivity to be administered. Becquerel is commonly a measure used internationally.

BETA RADIATION: are radioactive particles that are smaller, travel a greater distance, and can penetrate through a body. Beta radiation emits less energy than alpha. It takes 1,500-2,000 hits from a beta particle to damage DNA. Beta radiation can be used to treat cancers.

CHELATOR: a critical component of the radioligand construct that binds the radioisotope in a tight stable coordination so it can be properly directed to the desirable target.

CURIES: a measure of the quantity of radioactivity to be administered. Curie is commonly a U.S. measure.

GAMMA RADIATION: a high energy electromagnetic radiation without mass. Gamma radiation travels a long distance and is commonly used for imaging purposes.

GRAY: is an international unit to describe the absorbed dose of radiation to a given organ or bodily tissue.

HALF-LIFE (t ½): the amount of time that it takes for half of the radioactive atoms of a radioisotope to decay. Typically, a radioisotope is considered non-radioactive after 10 half-lives.

IONIZING RADIATION: a type of radiation that emits enough energy that it can make other atoms in its path unstable and radioactive.

LIGAND: a component of a radioligand construct. The ligand has the ability to connect with a radioisotope and deliver the radioisotope to a specific target. Ligands used is Theranostics are typically either an Antibody or a Small Molecule each of which have different properties.

LINKER: a critical component of the radioligand construct that links the ligand to the radioisotope. The linker determines the stability of the RLT while in circulation, prevents premature release of the radioisotope before it reaches the target, and also provides an efficient release of the radioisotope at the target.

MOLECULAR IMAGING: a theranostic that utilizes a Positron (Beta+) radioisotope combined with a ligand that delivers the radioisotope to a specific target on a cancer cell. This is commonly referred to as Positron Emission Tomography (PET Scan) and is used for imaging a cancer.

NEUTRON PARTICLES: a form of ionizing radiation that presents as free neutrons. Typically produced during a phenomena called nuclear fission or nuclear fusion. Neutron radiation is very penetrating. It can take several feet of concrete to stop neutron radiation.

NON-IONIZING RADIATION: a type of radiation that does not emit enough energy to make other atoms in its path unstable or radioactive. Forms of Non-ionizing radiation include: light, microwaves, and radiowaves.

PRECISION MEDICINE: the ability to deliver a treatment or imaging agent to a specific target on a cancer cell. Precision Medicine allows for higher effectiveness of a treatment or image with fewer side effects since it is not affecting other cells.

RADIATION: energy that travels through space. Radiation is caused by unstable atoms that emit energy as they decay in an attempt to become stable. Radiation may be non-Ionizing, which gives off less energy and unable to destabilize another atom. Examples of non-ionizing include: light, heat, and radio waves. Radiation may also be ionizing, which gives off more energy and is able to destabilize other atoms.

RADIOACTIVE DECAY: the process where an unstable atom loses particles which give off energy (radiation) in an attempt to become stable (non-radioactive)

RADIOISOTOPES: the unstable for an element that is emitting radiation during its decay mode in an attempt to become stable

RADIOLIGAND TARGET: a specific protein or receptor that is expressed on a cancer cell that the radioligand is targeting. Ideal targets are abundant on a cancer cell and specific to only cancer cells and not normal cells. This minimizes side effects from the radioligand affecting non-cancer cells. For example, PSMA is a target common for prostate cancer. However, PSMA is also found on salivary glands. So RLTs targeting PSMA on prostate cancer will also affect the salivary glands leading to dry mouth as one potential side effect.

REM: a measure of equivalency of the amount of radiation absorbed used commonly in the U.S.

SIEVERTS: a measure of equivalency of the amount of radiation absorbed used internationally.

TARGETED RADIOLIGAND THERAPEUTIC: a theranostic that utilizes an Alpha or Beta radioisotope with a ligand that delivers the radioisotope to a specific target on a cancer cell. This is a form of treatment for the cancer.

THERANOSTICS: the combination of a radioisotope to a ligand that binds to a specific target on a cancer cell. Theranostics can provide imaging or therapeutic results depending on which radioisotope is used. Theranostics is the combination of 2 words THERApeutic & diagNOSTIC.

X-RAY RADIATION: a high energy electromagnetic radiation without mass. X-Ray radiation travels a long distance and can be used for imaging or treatment of a cancer.