What is radiation therapy?

In order to kill or shrink cancer cells, radiation therapy uses high-energy particles or waves like X-rays, gamma rays, or charged particles. Radiation therapy disrupts the DNA within cancer cells, preventing them from proliferating and dividing, ultimately causing them to die. Radiation therapy can be applied independently or with other therapies like surgery and chemotherapy. The type of radiation therapy used and the length of the course of treatment are determined by the type and stage of cancer, the location of the tumour, the patient's age and general health, and other medical concerns. Radiation treatment aims to treat cancer with the appropriate radiation dose while causing the least harm to neighbouring healthy tissues.

What is radiation therapy made of?

X-rays, gamma rays, or charged particles like protons or electrons are examples of high-energy particles or waves commonly used in radiation therapy. These particles or waves are generated by linear accelerators, which deliver the radiation to the cancerous tissue. A kind of radiation therapy called ionising radiation has sufficient energy to free securely bonded electrons from atoms or molecules, producing charged particles known as ions. Cancer cells may die due to the DNA damage caused by this ionisation process. Internal radioactive sources, such as radioactive seeds or pellets, can also be used to administer radiation therapy to a tumour. The term for this procedure is referred to as brachytherapy.

How do you administer radiation therapy?

Depending on the type and area of cancer, radiation therapy can be delivered in various methods. Here are a few popular techniques:

  • Brachytherapy
    In order to perform brachytherapy, a radiation source must be put inside or close to the tumour. The source of the radiation can be a tiny radioactive seed or pellet, a tube or wire that transmits radiation, or both. Brachytherapy may be temporary or permanent, depending on the type of cancer being treated.
  • External beam radiation therapy (EBRT)
    entails aiming high-energy radiation beams from the exterior of the body at the tumour. A device known as a linear accelerator administers radiation to the affected area while the patient is lying on a treatment table. Over the course of several weeks, treatment sessions are often arranged daily and last only a few minutes.
  • Image-guided radiation therapy (IGRT)
    In order to precisely pinpoint the tumour before each radiation therapy, imaging methods, such as CT scans, MRIs, or PET scans, are used. By doing this, the radiation exposure to neighbouring healthy tissues is reduced, and the radiation is administered to the intended location.
  • Intensity-modulated radiation therapy (IMRT)
    is a specific type of external beam radiation therapy that uses radiation beams that are controlled by computers to target the tumour from various angles. The strength of the beams can be changed to provide the tumour with a more potent dosage of radiation while exposing healthy tissue to the least amount of radiation possible.
  • Stereotactic body radiation therapy (SBRT)
    In this specialised form of radiation therapy, large radiation doses are administered across a few sessions, which typically last one to five days. It is frequently used to treat tiny spine, liver, and lung tumours.

What is the outcome of radiation therapy?

Radiation therapy is often very effective at treating cancer and can have the following effects:

  • Cancer control
  • Cure
  • Tumour shrinkage



Are there side effects of radiation therapy?

The adverse effects of radiation therapy include exhaustion, rashes on the skin, nausea, and diarrhoea. These side effects can be treated with medicine or other treatments. Additionally, radiation therapy can have long-term adverse effects, such as harming healthy tissues, but overall, the advantages of the treatment exceed the dangers.


How often do I need radiation therapy?

Radiation therapy is often administered five days a week for several weeks.


At what stage of cancer is radiation therapy recommended?

The following are a few stages at which radiation therapy might be suggested:

  • Early-stage cancer
  • Locally advanced cancer
  • Metastatic cancer
  • Palliative care
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