How does a cell regulate the repair of its damaged DNA?

Human DNA can be modified or damaged in a variety of ways that can alter its sequence and potentially change the information that it encodes, from UV radiation to chemicals in our own bodies. One way the body can accurately ...

Terahertz radiation can disrupt proteins in living cells

Researchers from the RIKEN Center for Advanced Photonics and collaborators have discovered that terahertz radiation, contradicting conventional belief, can disrupt proteins in living cells without killing them.

Chemotherapy drugs react differently to radiation while in water

Cancer treatment often involves a combination of chemotherapy and radiotherapy. Chemotherapy uses medication to stop cancer cells reproducing, but the medication affects the entire body. Radiotherapy uses radiation to kill ...

Climate change could decrease Sun's ability to disinfect lakes

Increasing organic runoff as a result of climate change may be reducing the penetration of pathogen-killing ultraviolet (UV) sunlight in inland lakes, rivers, and coastal waters, according to a new study in the journal Scientific ...

Chip packets help make safer water in Papua New Guinea

University of Adelaide mechanical engineering students and staff have designed a low-cost and easily made drinking water treatment system suitable for remote communities in Papua New Guinea (PNG) – using foil chip packets ...

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Radiation therapy

Radiation therapy (also radiotherapy or radiation oncology, sometimes abbreviated to XRT) 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). Radiotherapy may be used for curative or adjuvant cancer treatment. It is used as palliative treatment (where cure is not possible and the aim is for local disease control or symptomatic relief) or as therapeutic treatment (where the therapy has survival benefit and it can be curative). Total body irradiation (TBI) is a radiotherapy technique used to prepare the body to receive a bone marrow transplant. Radiotherapy has several applications in non-malignant conditions, such as the treatment of trigeminal neuralgia, severe thyroid eye disease, pterygium, pigmented villonodular synovitis, prevention of keloid scar growth, and prevention of heterotopic ossification. The use of radiotherapy in non-malignant conditions is limited partly by worries about the risk of radiation-induced cancers.

Radiotherapy is used for the treatment of malignant tumors (cancer), and may be used as the primary therapy. It is also common to combine radiotherapy with surgery, chemotherapy, hormone therapy or some mixture of the three. Most common cancer types can be treated with radiotherapy in some way. The precise treatment intent (curative, adjuvant, neoadjuvant, therapeutic, or palliative) will depend on the tumour type, location, and stage, as well as the general health of the patient.

Radiation therapy is commonly applied to the cancerous tumour. The radiation fields may also include the draining lymph nodes if they are clinically or radiologically involved with tumour, or if there is thought to be a risk of subclinical malignant spread. It is necessary to include a margin of normal tissue around the tumour to allow for uncertainties in daily set-up and internal tumor motion. These uncertainties can be caused by internal movement (for example, respiration and bladder filling) and movement of external skin marks relative to the tumour position.

To spare normal tissues (such as skin or organs which radiation must pass through in order to treat the tumour), shaped radiation beams are aimed from several angles of exposure to intersect at the tumour, providing a much larger absorbed dose there than in the surrounding, healthy tissue.

This text uses material from Wikipedia, licensed under CC BY-SA