Eric Rountree, age 16, of Freeport, I11., for his question:
WHEN DID THE USE OF RADIOLOGY ORIGINATE?
Radiology in medicine is the branch of medical science that concerns the use of radiant energy in the diagnosis and treatment of disease. Radiology had its origin in the discovery of X rays in 1895 by a German physicist named Wilhelm Roentgen. Roentgen was awarded the first Nobel Prize in physics for his work.
Radiant energy, which can take the form of X rays or other types of radiation, is energy that results from atomic disintegration. Both diagnostic and therapeutic radiology, which are practiced by doctors of medicine and osteopathy, involve the use of ionizing radiation.
Therapeutic radiology, also referred to as radiation oncology, has as its principal basis the use of ionizing radiation. Increasingly common, however, is its use in conjunction with radiation therapy of other forms of treatment, such as hyperthermia (induced fever) and drugs.
Diagnostic radiology is the evaluation, by means of static or dynamic radiologic images, both of normal anatomy and physiology and of alterations of normal tissue resulting from disease or injury.
The great majority of these images are the result of passing a localized beam of X rays through the part of the body being examined, producing a static image on film. The image, called a radiograph, or X ray picture, can take several forms. It may be a plain radiograph, such as the common chest X ray; a tomograph, which is a radiograph obtained by timing the X ray exposure to coincide with simultaneous movement of the X ray tube and film in opposite or irregular directions around a predetermined plane in the body; or, finally, a computerized axial tomography scan, the computer analysis of a sharply limited, thin X ray beam passes circumferentially through an area of the body, producing a crosss section image.
Therapeutic radiology is the treatment of malignant disease with ionizing radiation, either alone or in conjunction with hyperthermia or drugs.
The practice of the use of therapeutic radiology stems from the discovery of naturally occurring radioactive elements in the late 19th century. Such treatment is often described in terms of the energy of the beam employed; superficial (less than 120 kilovolts, or kv), orthovoltage (120 to 1,000 kv) and megavoltage (greater than 1,000 kv).
Superficial radiation therapy is used in treating malignant diseases involving the skin, the eye or other body surfaces. Orthovoltage therapy has been largely replaced by megavoitage (cobalt, linear accelerator and betatron) therapy. This latter provides more efficient and effective delivery of the intended radiation dose to tumors deep within the body and, at the same time, spares the skin and surrounding normal tissue as much as possible.
Radiation therapy may be used alone as the treatment of choice in most cancers of the skin; in certain stages of cancer involving the cervix, uterus, breast and prostate; and in some types of leukemia and lymphoma, particularly Hodgkin's disease
When used alone, radiation therapy is intended to effect a cure. When radiation therapy is used in conjunction with cancer treatment drugs (combined modality therapy), however, it may be intended for either cure or the relief of symptoms.