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Glossary

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  1. Ra
  2. Rb
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  27. R0-9
 

List of terms beginning with Ra

Radiation

Means giving off energy particles or waves, including heat or light (see ' electromagnetic radiation'). But often used to mean radioactive radiation, in other words gamma rays or alpha or beta particles from a radioactive source. The radioactivity comes from the breakdown of atoms. The source can be natural or made in a nuclear reactor. Uncontrolled radiation can be dangerous and cause cancer. Controlled exposure to radiation can be used in medicine for diagnosis (for example X-rays) or to treat cancer ( radiotherapy).

Radiation necrosis

Damage to normal tissue that may occur after radiotherapy or exposure to other ionising radiation.

Radical cystectomy

Surgery to remove the bladder and nearby lymph nodes to treat bladder cancer.

Radical hysterectomy

Surgery to remove the uterus, cervix and part of the vagina.

Radical mastectomy

Surgery to remove the breast, lymph glands under the arm and muscles of the chest wall. Only done if a breast cancer has spread to the muscles of the chest wall.

Radioactive

A substance that is capable apable of emitting high-energy rays or particles as radiation.

Radiotherapy

Cancer treatment that uses high-energy electromagnetic radiation such as x-rays to kill cancer cells. During radiotherapy, a significant amount of healthy normal tissue is sometimes irradiated. To reduce the side effects caused by this, the radiation dose is often split into a number of treatments, enabling the normal healthy tissue to recover before the next treatment is given.

Radium

One of the earliest known radioactive metals. Radiotherapy used to be called 'radium treatment' because all radiotherapy used to be given using radium.

Randomised controlled trials

Participants are randomly split into groups. One group is given the treatment being tested while another group - the control group - is given an alternative treatment or placebo. Researchers then compare the effects of the different treatments.

Rate

Expresses how frequently something (such as a cancer) occurs in a given population (such as the UK) over a given period of time (usually a year). For example, the UK has a population of about 60 million and each year in the UK about 270,000 people are diagnosed with cancer. To get the rate, the number of people diagnosed each year (270,000) is divided by the size of the population (60 million) and multiplied by 100,000. This gives us a crude rate of around 450 cancers per 100,000 population.

Ratio(s)

Relationship between two groups or amounts that expresses how much bigger one is than the other. For example, the ratio of men to women at the conference was ten to one (or 10:1).