Radiotherapy refers to treatment of various malignant and benign diseases by ionizing radiations. The effect of radiotherapy on malignant cells compared to normal cells, is related to the sensitivity of the cells to radiation. Malignant cells are radiosensitive when compared to normally proliferating cells such as fibroblasts, lymphocytes. That is why radiotherapy is used effectively in treating cancerous and noncancerous malignancies. In contrast, it is less effective in halting proliferation of tissues such as bone and other tissues where abnormal cell proliferation plays a vital role in framing healthy bone remodeling process
What is radiotherapy?
Radiation Therapy (or radiotherapy) is the use of ionizing radiation to treat a disease. The ionizing radiation can be from X-rays, gamma rays or charged particles. In medicine, the term is usually used to refer to the treatment of malignant tumors with the purpose of cure. The treatment itself is called radiotherapy, radiation therapy, irradiation or simply XRT.
Radiation therapy can be used alone (called primary radiation therapy) or in combination with surgery and/or chemotherapy (called adjuvant), as part of a curative intent (with aim to cure), a palliative treatment (to control symptoms, pain and bleeding but not cure) or as a result of an experimental protocol (such as in clinical trials).
Radiotherapy can be delivered externally, using a linear accelerator machine that produces high energy photons and electrons that are directed at the tumor site. Alternatively it can be delivered internally, using either sealed radioactive sources that are placed close to or inside the cancerous tumor or by injecting a liquid that contains radioactive material directly into the bloodstream close to where the cancerous cells are located.
How does radiotherapy work?
Radiation therapy uses high-energy x-rays to destroy cancer cells. The x-rays are produced by a machine outside the body and are aimed at the cancer. Healthy cells can also be affected by radiotherapy, but they usually recover.
In some cases, radiotherapy can be given as the only treatment for cancer (for example, in cases of early prostate cancer). In other cases, it is used alongside other treatments such as chemotherapy or surgery.
Radiotherapy is most commonly used to treat solid tumours such as cancers of the breast, lung or prostate. It can also be used to treat non-cancerous growths such as thyroid nodules or acoustic neuromas.
Sometimes radiotherapy is used to prevent cancer from returning after an operation (adjuvant radiotherapy) or to relieve symptoms of advanced cancer (palliative radiotherapy).
Is radiotherapy effective?
Radiotherapy, also known as radiation therapy, is an effective treatment for cancer. It is commonly used in conjunction with other cancer treatments such as chemotherapy.
How does radiotherapy work to treat cancer?
The cells in our body grow at different rates. For example, skin cells divide slowly, but blood cells divide very quickly.
Cancer cells are abnormal and divide rapidly to form a tumour. The DNA gets damaged by the radiation and can no longer control how the cell grows or divides.
Over time, the healthy cells in the treatment area can recover from the effects of radiotherapy and go back to functioning normally. However, some types of cells are more sensitive to radiation and may not be able to repair themselves completely. This can cause side effects
How do I prepare for radiotherapy?
You may need to take a series of blood tests and have an ECG before you have radiotherapy. You may be asked to fast for 6 hours before the treatment. This simply means not eating or drinking anything except water during this time.
Your radiotherapy team will advise you about the specific side effects you may experience from your treatment. They will also give you advice on how to manage these side effects, including suggesting the best ways to relieve pain and discomfort.
It is important to tell your doctor or nurse if you are in any pain or discomfort, as soon as it starts. There are many different medicines that can help control pain and other symptoms.
Types of radiotherapy
There are two main types of radiotherapy:
External beam radiotherapy uses high energy x-rays which are generated by a machine outside the body and carefully aimed at a tumor inside the body.
Internal radiotherapy uses sealed radioactive sources which are either inserted into the tumor or placed close to it (“interstitial”), or swallowed (“endocavitary”), or which give off their radiation directly into a specific organ (“intraluminal”), or implanted under the skin (“interstitial brachytherapy”). The sources used for internal Brachytherapy.
External beam radiotherapy (EBRT)
External beam radiotherapy (EBRT) uses radiation beams from a linear accelerator to treat cancer, which can destroy cancer cells or slow their growthThe therapy can be used as a treatment for some types of cancer. These include tumors in the brain, prostate gland, lungs, breast and cervix. It also can be used to treat cancers of the head and neck, liver, bladder and rectum. EBRT is used alone or in combination with chemotherapy or surgery.
There are different types of EBRT.
Conformal radiation therapy (CRT) treats specific areas, while reducing exposure to nearby healthy tissue.
Intensity-modulated radiation therapy (IMRT) targets specific areas by changing the intensity of the beams during treatment.
Image-guided radiation therapy (IGRT) uses imaging techniques during treatment to make sure the radiation is precisely targeting your tumor.
Stereotactic radiosurgery (SRS) delivers multiple beams at once from different directions to target a small area such as brain tissue that may not be reachable with other types of EBRT. This approach requires very precise
Radio therapy is a method of administering high energy beams of radiations from an external point source to the patient through the use of a machine to treat various diseases. The machine consists of high energy source of radio frequency and antenna which are used as source for incisive radiations.
