"The treatment using ionizing radiation, generally provided as part of cancer therapy, to either kill or control the growth of malignant cells."
The use of radiation to treat cancer and other medical conditions.
Basics of radiation: Radiation is energy in the form of waves or particles. It is emitted by radioactive materials and can have both beneficial and harmful effects.
Types of radiation: There are three types of radiation: alpha, beta, and gamma. Alpha particles are the heaviest and least penetrating, while gamma rays are the lightest and most penetrating.
Radiation detection: Radiation can be detected and measured using instruments such as Geiger counters, dosimeters, and scintillation detectors.
Radioactive decay: Radioactive materials decay over time, releasing radiation in the process. The decay rate is measured in half-life, or the time it takes for half the material to decay.
Radiation safety: Proper safety measures must be taken when working with radioactive materials to minimize exposure and prevent harm to people and the environment.
Radiation therapy: Radiation therapy is a form of treatment for cancer that uses high-energy radiation to destroy cancer cells.
Radiation dose: The amount of radiation delivered to a patient during radiation therapy is carefully measured to ensure the optimal dose is delivered while minimizing harm to healthy tissue.
Radiation sources: Radiation sources used in radiation therapy include x-rays, gamma rays, and electron beams.
Radiation planning: Before radiation therapy begins, a team of health professionals works together to develop a treatment plan that ensures the radiation is delivered to the right area and at the right dose.
Radiation side effects: Radiation therapy can cause side effects, such as fatigue, skin changes, and nausea. These side effects can be managed with medication and other treatments.
Radiation oncology: Radiation oncology is the medical specialty that focuses on the use of radiation therapy to treat cancer.
Radiobiology: Radiobiology is the study of the biological effects of radiation on living things.
Radiopharmaceuticals: Radiopharmaceuticals are drugs that contain a radioactive substance and are used in nuclear medicine to diagnose and treat disease.
Radiation exposure: Both natural and human-made sources of radiation can expose people to radiation. This exposure can be harmful if levels are too high.
Radiation regulations: Governments around the world have established regulations to ensure that radiation exposure is kept at safe levels for both people and the environment.
External beam radiation therapy: This is the most common type of radiation therapy, in which high-energy X-rays or other types of radiation beams are used to destroy cancer cells. The radiation is directed from a machine outside the body and is carefully aimed at the tumor location.
Internal radiation therapy (Brachytherapy): This therapy delivers radiation directly into the tumor site by placing a small radioactive source in or near the tumor using needles or catheters. This type of therapy is often used for prostate cancer.
Stereotactic body radiotherapy (SBRT): This is a highly precise form of external radiation therapy that delivers a high dose of radiation to a specific target in the body. It is commonly used to treat small tumors or metastases in the lungs, liver, and bones.
Intensity-modulated radiation therapy (IMRT): This is a highly advanced form of external radiation therapy, which uses computer-controlled X-ray beams that can be modulated in intensity and direction to conform to the shape of the tumor while sparing surrounding healthy tissue.
Proton therapy: This is a type of external radiation therapy that uses protons instead of X-rays to target cancerous cells. The beams are highly targeted and can minimize damage to surrounding healthy tissue.
Radiopharmaceutical therapy: This uses radioactive isotopes that are injected into the patient’s bloodstream, which travels to cancer cells throughout the body. This type of therapy is commonly used to treat thyroid, bone, and neuroendocrine tumors.
Radioimmunotherapy: This is a type of cancer treatment that combines radiation therapy and immunotherapy. A radioactive marker is attached to an antibody that targets specific cancer cells. The radiation destroys the cancer cells while the antibodies activate the patient’s immune system to attack the remaining cancer cells.
Tomotherapy: This is a type of external beam radiation therapy that combines image-guided intensity-modulated radiation therapy (IMRT) with computed tomography (CT) scanning. It delivers targeted radiation to the tumor while minimizing exposure to surrounding healthy tissue.
Gamma knife radiosurgery: This is a form of stereotactic radiation therapy that uses highly focused gamma rays to target tumors or other abnormalities in the brain. It is a non-invasive procedure and does not require incisions or anesthesia.
Electromagnetic radiation therapy: This type of cancer treatment uses electromagnetic fields to destroy cancer cells. It is still considered experimental and is not widely used in clinical practice.
"It is normally delivered by a linear particle accelerator."
"Radiation therapy may be curative in a number of types of cancer if they are localized to one area of the body and have not spread to other parts."
"It may also be used as part of adjuvant therapy, to prevent tumor recurrence after surgery to remove a primary malignant tumor."
"Ionizing radiation works by damaging the DNA of cancerous tissue leading to cellular death."
"To spare normal tissues... shaped radiation beams are aimed from several angles of exposure to intersect at the tumor, providing a much larger absorbed dose there than in the surrounding healthy tissue."
"The radiation fields may also include the draining lymph nodes if they are clinically or radiologically involved with the tumor, or if there is thought to be a risk of subclinical malignant spread."
"These uncertainties can be caused by internal movement (for example, respiration, and bladder filling) and movement of external skin marks relative to the tumor position."
"Radiation oncology is the medical specialty concerned with prescribing radiation, and is distinct from radiology, the use of radiation in medical imaging and diagnosis."
"It is also common to combine radiation therapy with surgery, chemotherapy, hormone therapy, immunotherapy or some mixture of the four."
"The precise treatment intent (curative, adjuvant, neoadjuvant therapeutic, or palliative) will depend on the tumor type, location, and stage, as well as the general health of the patient."
"Total body irradiation (TBI) is a radiation therapy technique used to prepare the body to receive a bone marrow transplant."
"Brachytherapy, in which a radioactive source is placed inside or next to the area requiring treatment, is another form of radiation therapy that minimizes exposure to healthy tissue during procedures to treat cancers of the breast, prostate, and other organs."
"Radiation therapy has several applications in non-malignant conditions."
"The treatment of trigeminal neuralgia, acoustic neuromas, severe thyroid eye disease, pterygium, pigmented villonodular synovitis, and prevention of keloid scar growth, vascular restenosis, and heterotopic ossification."
"The use of radiation therapy in non-malignant conditions is limited partly by worries about the risk of radiation-induced cancers."
"The subspecialty of oncology concerned with radiotherapy is called radiation oncology."
"A physician who practices in this subspecialty is a radiation oncologist."
"Radiation therapy is synergistic with chemotherapy, and has been used before, during, and after chemotherapy in susceptible cancers."
"Most common cancer types can be treated with radiation therapy in some way."