Links & Glossary

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• Nuclear Med. Glossary A-D
• Nuclear Med. Glossary E-H
• Nuclear Med. Glossary I-O
• Nuclear Med. Glossary P-R
• Nuclear Med. Glossary S-Z

Nuclear Med. Glossary I-O

The Nuclear Medicine Glossary by Richard Zimmerman, IBA Letters I to O

Incidence:

Number of new cases of a disease appearing during a certain period of time (usually one year).

IND:

Investigational New Drug (dossier) - dossier containing all data gathered so far and required to obtain the authorization to perform a clinical trial.

Internal radiotherapy:

method of therapy by irradiation using a sealed radioactive source inserted into a natural cavity or implanted, temporarily or permanently, into the tissues. Synonym for curietherapy. Domain of the radiotherapist.

Intracavity radiation:

the emission of rays from a source placed inside a cavity: uterus, throat.

Intraoperative radiation:

irradiation during a surgical operation.

Ionizing:

(radiation): electromagnetic or corpuscular radiation capable of producing ions (positively or negatively charged atoms or molecules) directly or indirectly during its passage through matter. This transformation of the molecules is considered to be destructive and induces a biological change. X-, β⁺-, and γ-rays are considered weak ionizers compared with β^-- and above all with α-rays.

Irradiation:

exposure to radiation, without physical contact with the radioactive material; not to be confused with contamination in which there is a transfer of radioactive material. Once outside the radioactive field, the person is no longer exposed to the effects of the radiation.

Isotope:

All the atoms, the nucleid of which have the same number of protons, form a chemical element. There are 92 natural elements, to which 17 known artificial elements must be added. When a given number of protons are associated in an atom with different numbers of neutrons, they represent variant chemical elements called isotopes. In most cases only a few forms are stable; the other unstable forms are called radioisotopes or radionuclides. Of the 109 currently known elements, 28 exist only in an unstable, that is to say radioactive, form. This is the case for uranium, plutonium, and radium. There are more than 3,000 known radionuclides.

Label:

an entity (simple or complex) which, due to its radiation or its color, can be monitored in a complex biological system.

Labeling:

method of chemical fixation of a radioisotope on a non-radioactive molecule.

Ligand:

part of the molecule joining the vector to the central radioactive atom and which can also confer particular properties on the whole, such as better solubility or better ability to be absorbed by cells.

Metabolic radiotherapy:

method of therapy by selective irradiation of a target zone by a molecule participating in the metabolism and labeled with a radioisotope, injected into the patient. Domain of the nuclear physician.

MRI:

magnetic resonance imaging; another name for medical nuclear magnetic resonance.

NDA:

New Drug Application - dossier containing all data generated during the development of a drug that has to be filed in order to obtain a Marketing Authorization.

Neutron:

a neutral elementary particle (with no electrical charge), a constituent of the nucleus of the atom together with the proton.

Neutron therapy:

external radiotherapy using a neutron beam.

Nuclide:

atomic nucleus.

Oncology (or cancerology):

medical science covering the field of prevention, detection, and treatment of cancers.

Orphan drug:

substance that has been developed for a disease that is rare, an orphan disease, that would not be considered a high priority by industry without incentives. Depending on the country, a disease can be considered as an orphan if it affects less than 5 out of 10,000 individuals in the population.