(redirected from radiotherapists)
Also found in: Dictionary, Thesaurus, Medical.


the treatment of disease, esp cancer, by means of alpha or beta particles emitted from an implanted or ingested radioisotope, or by means of a beam of high-energy radiation
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.



the therapeutic use of several kinds of ionizing radiation of varying energies.

Radioactivity was found to have a biological effect on the body shortly after the discovery of radioactive substances by A. Becquerel in 1896 and the study of them by P. Curie. (Originally, radiotherapy was called curietherapy.) The French physicians E. Benier and H. Denlaut were the first to use irradiation with radium for therapeutic purposes (1897). Further research revealed that young, rapidly growing and multiplying cells were the most sensitive to the process; this became the basis for using radioactive radiation to destroy malignant tumors, which consist of such cells.

There are many kinds of radiotherapy, including alpha, beta, gamma, neutron, pi-meson, proton, X-ray, and electron. The use of radiotherapy is based on a number of factors. First, ionizing radiation induces functional and anatomical changes in tissues, organs, and the body as a whole. It suppresses the capacity of cells for growth and multiplication and causes the death of tissue elements of the irradiated organ. (The extent of injury to the irradiated tissues is directly proportional to the dose absorbed.) Second, pathologically altered tissues (tumorous, degenerative, or inflamed) are more sensitive to radiation than are normal tissues. Finally, the use of radiotherapy is based on the response of the body and of the individual organs and tissues to irradiation.

Slight radiation injury is reversible, and the response of irradiated tissue is manifested in compensation for or even intensification of the diminished or lost function. With deep anatomical injuries to irradiated tissues, however, the process is irreversible, and the dead elements are replaced by nonfunctional connective tissue. Therefore, in some cases, the purpose of radiotherapy is either to intensify or to suppress the function of the given organ. In other cases (for example, with such malignant tumors as cancer or sarcoma) the intention is to suppress vital activity completely and destroy the pathologically altered tissues.

An important prerequisite for effective radiotherapy is the choice of radiant energy and the dose to be absorbed by the tissues. Radioisotopes (60Co, 137Cs, 32P, 198Au, 137I, 192Ir), X-ray equipment, gamma-ray sources, and charged-particle accelerators (linear accelerators, cyclotrons, and betatrons) are used as sources of ionizing radiation.

Depending on the location of the source of radiation in relation to the irradiated organ, irradiation is described as internal or external. Internal irradiation is produced by introducing a radioactive substance orally or intravenously; the substance, which emits charged particles and gamma rays, gradually distributes itself in the various organs and tissues. External irradiation may be general (whole-body) or local. Whole-body irradiation is used only rarely; the local irradiation of an organ or a limited part thereof (with the other parts shielded) is the principal method of radiotherapy.

Remote irradiation (teletherapy) is used to treat deep-lying foci. The radiation source (gamma sources, X-ray machines, accelerators) is placed at a considerable distance from the skin (30-120 cm). Short-focus irradiation, in which the source (X-ray machines or devices with a 60Co or 192Ir charge) is kept no more than 3-7 cm from the skin, is the method generally used to treat skin diseases, especially malignant tumors. Skin diseases are also treated by contact irradiation or by the application to the skin or mucous membrane of radioactive preparations emitting alpha or beta particles.

Various methods are used for intracavitary irradiation. The small tube of a special close-focus X-ray machine is inserted directly into a body cavity, such as the mouth, vagina, or rectum. A rubber balloon filled with a solution of the radioactive substance, a metal case with tubes containing a radioisotope, or beads of 60Co are inserted into cavitary or tubular organs, such as the urinary bladder, uterus, or bronchus. A solution or suspension of a radioactive isotope can be injected into an organ or into the pleural or abdominal body cavity.

Interstitial irradiation is achieved by introducing needles or tubes containing 60Co or 192Ir into the tissues. Colloidal solutions containing 198Au or granules of 198Au can also be introduced into the tissues. Radiotherapy is commonly combined with surgery, drug therapy, hormonal preparations, dietary regulation, and other types of treatment, since a combination of methods is most effective.


Domshlak, M. P. Ocherki klinicheskoi radiologii. Moscow, 1960.
Kozlova, A. V. Metodika primeneniia radioaktivnykh izotopov s lechebnoi tsel’iu. Moscow, 1960.
Kozlova, A. V. Luchevaia terapiia zlokachestvennykh opukholei. Moscow, 1971.
Luchevaia terapiia s pomoshch’iu izluchennii vysokoi energii. Moscow, 1964. (Translated from German.)
Fizicheskie osnovy luchevoi terapii i radiobiologii. Moscow, 1969. (Translated from French.)
Spravochnik po rentgenologii i radiologii. Edited by G. A. Zedgenidze. Moscow, 1972.


The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.


McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
There is only one radiotherapy machine for 20,000 patients, one medical oncologist for 20,000 patients, a radiotherapist for 12,500 patients, an indoor bed for 427 patients and a cancer specialist is available for 7,692 patients.
Characteristic Frequency Percentage (%) Age group (years) <45 325 85.8 >45 54 14.2 Sex Male 157 41.4 Female 222 58.6 Hospital Amana 102 26.9 Temeke 104 26.9 MNH 99 26.2 ORCI 74 19.5 Department/ward Medical wards 203 53.6 Surgical wards 171 45.1 ICU 5 1.3 Profession Doctors 182 48.0 Nurses 169 44.6 Others * 28 7.4 Duration in health care services <5 years 171 45.1 >5 years 208 54.9 History of antibiotic use Yes 185 48.7 No 194 51.3 History of chronic illness Yes 42 11.1 No 337 88.8 Hand washing Frequently 360 9.1 Occasionally 17 4.5 No 2 0.5 MNH, Muhimbili National Hospital; ORCI, Ocean Road Cancer Institute; ICU, intensive care unit; * anesthesiologist and radiotherapist. Table 2: Characteristics of study participants by MRSA or MSSA carriage status.
The specialist team - made up of radiotherapists, radiographers and physicists - from the Papillon department has seen a 30% increase in patients treated, rising from 100 patients per year to 130.
The PET-CT facility being equipped with state of the art 427 slice /sec CT scanner, Ultra HDPET with highly specialized 4D respiratory Gating software is a boon for cancer patients as the radiotherapists would be able to deliver highly precise radiation dose, synchronized with patients' breathing pattern.
Following completion of the chemotherapy phase, patients with complete or partial response would be seen every 3-6 months by oncologists and radiotherapists only.
We have received a request from The Association of Radiologists and Radiotherapists of Zimbabwe for member status of the RSSA for their diagnostic radiologists.
Thank you to James Cook University Hospital, Dr Aynesley and her team, the radiotherapists and the doctors and nurses on Wards 2, 9 and 15.
Besides the examination and making right diagnosis with adequate treatment in young children requires availability of other specialists: anesthesiologists, radiologists, chemotherapists and radiotherapists.
Written by radiation oncologists and radiotherapists from the US, Europe, and Canada, articles cover the history of local treatment for breast cancer; the role of radiation therapy in ductal carcinoma in situ and after neoadjuvant chemotherapy for operable breast cancer; advances in accelerated partial breast irradiation; proton radiation; hypofractionation; the role of postmastectomy radiotherapy and breast reconstruction; local recurrence and biological subtypes of breast cancer; intensity-modulated radiation therapy; radiation-induced heart disease; individualizing the risk of locoregional recurrence with molecular and genomic classifiers; and the current and future state of breast radiation therapy.
An oncologist also works together with cancer surgeons and radiotherapists.
LISTENING Labour leader Ed Miliband with radiotherapists at University College Hospital in London yesterday