Radiation therapy

Radiation therapy (or radiotherapy) is the medical use of ionizing radiation as part of cancer treatment to control malignant cells (not to be confused with radiology, the use of radiation in medical imaging and diagnosis). Although radiotherapy is often used as part of curative therapy, it is occasionally used as a palliative treatment, where cure is not possible and the aim is for symptomatic relief. Other rare uses are to wipe out the immune system prior to transplant to reduce the incidence of tissue rejection, called total body irradiation (TBI); to calm hyperactive muscles—such as might cause twitchy eyes—with mild superficial treatments; and to form scar tissue around a stent to reinforce the vascular wall.

Application

Radiotherapy is commonly used for the treatment of tumors. It may be used as the primary therapy. It is also common to combine radiotherapy with surgery and/or chemotherapy and/or hormone therapy. The most common tumors treated with radiotherapy are breast cancer, prostate cancer, lung cancer, colorectal cancer, head & neck cancers, gynaecological tumors, bladder cancer and lymphoma, although the cancer's stage (progress) and invasion into lymph nodes, as well as other health and (unfortunately) monetary factors affect which treatment will have the greatest possibility of success.

Related Topics:
Tumor - Surgery - Chemotherapy - Hormone therapy - Breast cancer - Prostate cancer - Lung cancer - Colorectal cancer - Head & neck cancers - Gynaecological tumors - Bladder cancer - Lymphoma - Stage

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Radiation therapy is commonly applied just to the localised area involved with the tumor. Often the radiation fields also include the draining lymph nodes. It is possible but uncommon to give radiotherapy to the whole body, or entire skin surface.

Related Topics:
Tumor - Skin

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

In order to spare interstitial tissue (such as skin or organs which radiation must pass through in order to treat the tumor) several angles of exposure are utilized such that the radiation beams overlap on top of each other at the tumor, providing a much larger absorbed dose there than in the surrounding, healthy tissue.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

In the past, before immunosuppressive drugs were developed, radiation therapy was also used to prevent unwanted immune reactions following organ transplantation or in autoimmune diseases. Total body irradiation may be given as a preparative regimen for an allogeneic bone marrow transplant.

Related Topics:
Immunosuppressive drug - Immune reaction - Organ transplantation - Autoimmune disease - Bone marrow transplant

~ ~ ~ ~ ~ ~ ~ ~ ~ ~