Radiation therapy in treatment of cancer
Radiation therapy is a type of cancer treatment that destroys cancer cells using beams of intense radiation. Very commonly, radiation therapy uses X-rays, but it is also possible to use protons or other energy forms. Radiotherapy involves the use of radiation to treat cancer cells, usually x-rays. You might receive radiotherapy, called internal radiotherapy, from within the body. Or external radiotherapy that comes from outside the body.
Radiotherapy may be used to try to treat cancer, to decrease the risk of cancer returning, or to help alleviate symptoms. You can have it on your own or with other therapies, such as surgery or chemotherapy.
During their cancer treatment, almost 50 out of 100 (50 percent) individuals have radiotherapy at some stage.
Photons are used for most radiotherapy types. Yet you can have protons or more rarely, electrons. Your doctor will determine what kind you’re going to need.
By destroying the structure of dividing cells, radiotherapy kills cancer cells and shrinks tumors. Usually, cancer cells divide more rapidly than in normal tissue, so they are especially susceptible to radiotherapy.
Radiotherapy is used to kill malignant tumors, improve surgical or other treatment outcomes (adjuvant therapy), relieve symptoms, and decrease metastases. At any point in their recovery, about half of cancer patients undergo radiotherapy.
Typically, radiotherapy is specifically targeted at the tumor or metastases. Radiotherapy can often be provided in the upper body for the treatment of widely spread cancer.
By injecting a radioactive source into the body in various ways, radiotherapy may be performed externally by a computer or internally. There are a number of internal radiotherapy techniques. Radioactive medication is administered intravenously or orally into the body by radioisotope therapy or radiopharmaceutical therapy. The tumour is directly affected by nuclear medication, and healthy tissue is just marginally damaged. For example, one type of radioisotope therapy is radioiodine, which is used to treat thyroid cancer.
The preference between surgery and radiotherapy depends on the efficacy of the procedure and its disadvantages if the cancer is localized. In particular, with the advancement of conservation methods of treatment, the importance of radiotherapy in cancer treatment has increased.
How radiotherapy works ?
Radiotherapy is a form of ionizing radiation (high energy) that, by damaging the DNA of these cells, destroys the cancer cells in the treated region. Radiation also affects cells that are normal. In the treatment area, this can cause side effects.
A few weeks after treatment, side effects typically improve, but some can persist in the long term. Before you start treatment, the doctor will talk things through with you and explore potential ways to handle side effects.
At high doses, by destroying their DNA, radiation therapy destroys cancer cells or delays their development. Cancer cells whose DNA is damaged stop dividing or die beyond repair. When the weakened cells die, the body breaks them down and replaces them.
Radiation therapy does not immediately destroy cancer cells. Before DNA is weakened enough for cancer cells to die, it requires days or weeks of care. Then for weeks or months after radiation therapy finishes, cancer cells keep dying.
Types of Radiation Therapy
There are two main types of radiation therapy, external beam and internal beam.
The type of radiation therapy that you may have depends on many factors, including:
- The type of cancer
- The size of the tumor
- The tumor’s location in the body
- How close the tumor is to normal tissues that are sensitive to radiation?
- Your general health and medical history
- Whether you will have other types of cancer treatment
- Other factors, such as your age and other medical conditions,
External Beam Radiation Therapy
External radiation therapy for the beam comes from a computer that targets the cancer with radiation. The unit is big and can be noisy. It does not contact you, but can travel around you, sending radiation from several directions to a portion of your body.
A local treatment is external beam radiation therapy, which means it treats a particular part of the body. If you have lung cancer, for example, you have radiation just to your chest, not to your entire body.
Internal Radiation Therapy
Internal radiation therapy is a procedure in which the body is placed inside a radiation source. It may be solid or liquid from the source of radiation.
Brachytherapy is called internal radiation therapy with a solid source. Seeds, ribbons, or capsules containing a source of radiation are inserted in your body, in or near the tumor, in this form of treatment. Brachytherapy is a local procedure, much like external beam radiation therapy, which targets only a small part of the body.
The radiation source in your body can emit radiation for a while with brachytherapy.
Systematic therapy is called internal radiation therapy with a liquid source. Systemic means that the drug spreads to tissues in the body in the blood, looking for cancer cells and killing them. By swallowing, via a vein through an IV line, or by an injection, you get systemic radiation therapy.
With systemic radiation, for a time, the body fluids can give off radiation, such as urine, sweat, and saliva.
Why people with cancer receive radiation therapy ?
To cure cancer and relieve cancer symptoms, radiation therapy is used.
Radiation therapy can cure cancer, keep it from coming back or stop or delay its growth when used to treat cancer.
They are classified as palliative procedures when treatments are used to relieve symptoms. Radiation from the external beam can shrink tumors to treat discomfort and other complications caused by the tumor, such as difficulty breathing or loss of control of the bowel and bladder. Pain from cancer that has spread to the bone can be treated with radiopharmaceuticals called systemic radiation therapy medications.
Types of cancer that are treated with radiation therapy
External beam radiation therapy is used to treat many types of cancer.
Brachytherapy is most often used to treat cancers of the head and neck, breast, cervix, prostate, and eye.
A systemic radiation therapy called radioactive iodine, or I-131, is most often used to treat certain types of thyroid cancer.
Another type of systemic radiation therapy, called targeted radionuclide therapy, is used to treat some patients who have advanced prostate cancer or gastroenteropancreatic neuroendocrine tumors (GEP-NET). This type of treatment may also be referred to as molecular radiotherapy.
How is radiation Is used with other cancer treatment?
Radiation may be the only treatment you need for certain individuals. But most often, for other cancer therapies, such as surgery, chemotherapy, and immunotherapy, you can get radiation therapy. Before, during, or after these other procedures, radiation therapy may be provided to increase the chances that the treatment will succeed. The timing of radiation therapy depends on the type of cancer being treated and whether cancer treatment or symptoms are the aim of radiation therapy.
It can be given when radiation is associated with surgery:
- Shrink the size of the cancer before treatment so that it can be removed by surgery and be less likely to return.
- So that it goes directly to the cancer during surgery without going through the skin. Intraoperative radiation is referred to as radiation therapy in this manner. Physicians can more effectively shield surrounding normal tissues from radiation with this procedure.
- To destroy any living cancer cells after surgery.
Lifetime Dose Limits
The amount of radiation that an area of your body can safely receive over the course of your lifetime is limited. You will not be allowed to get radiation treatment for that area a second time, depending on how much radiation that area has already been treated with. However, if the safe lifetime dose of radiation has already been received by one area of the body, another area might still be treated if the distance between the two areas is large enough.
Side effects of radiotherapy
Radiotherapy affects normal cells and not just cancer cells in the body. For the most part, the impact on healthy tissue depends on the size of the dose of radiation, the duration of treatment, and which part of the body is receiving radiation. Adverse side effects appear only in the area where the radiation is applied to your body.
Radiotherapy side effects may already occur during the treatment period, immediately after treatment or later, even after a few years. In the division of tissue, such as in the skin, mucous membranes and bone marrow, the immediate side effects of radiotherapy are quickly apparent. Most side effects can be effectively avoided and treated nowadays.
We list the most common radiotherapy side effects below. You will be able to get more detailed information from the medical staff treating you about the side effects and their treatment.
Damage to the mouth and pharynx mucosa
Almost all patients receiving head and neck radiotherapy suffer damage to their mouth and to the mucosa of the pharynx. This is painful, makes it hard to eat, is prone to infection, and puts dental health at risk. Dry mouth may also cause radiation therapy given to the area of the saliva glands.
It is possible to treat damage to the mucosa in your mouth with preventive dental care, by treating infections, by using painkillers and by ensuring that you get enough nutrition.
Intestinal damage
Radiotherapy easily produces immediate side effects in the intestinal tract. Nausea, diarrhoea and irritation of the bowel and rectal area may be caused by radiation given to the abdominal and pelvic areas.
Depending on the composition of the area being treated and the size of the single and total radiation dosage, the degree of damage depends on the composition. Chemotherapy given at the same moment increases the side effects and complicates them. Radiotherapy given to the oesophagus, as well as pain and difficulty swallowing, can cause a sense of burning below the sternum.
Skin
Your skin may be reddened and peeling after radiotherapy. Redness of the skin may begin after 2-3 weeks and peel after 4-5 weeks after the start of radiotherapy in general. Your skin may turn darker as well. Protecting the skin area from sunlight under radiotherapy is important, as your skin remembers the radiotherapy dose it receives for your entire lifetime.
Bone marrow
In the bone marrow contained in your larger bones, blood cells are produced. A drop in the number of white blood cells, blood platelets and haemoglobin may be caused by radiotherapy given to the pelvic and spinal areas. Usually, this is temporary and your blood count will improve gradually.
External genital and bladder irritation
If the vulva and mucous membrane areas of a woman are treated with radiotherapy, it may cause soreness. The areas are painful, and they may get infected.
In the treatment of bladder cancer, endometrial cancer or prostate cancer, acute bladder irritation from radiotherapy occurs. You may feel a frequent need to urinate in this situation, blood may be in your urine, and you may have a distended lower stomach. It may also be painful to urinate.
Radiotherapy sequelae
In organs where tissue regeneration is slow, late side effects of radiotherapy may occur. Doctors and physicists planning your radiotherapy are aware of the sensitivity of different organs to radiation and plan treatment so that it is possible to avoid late side effects. But sometimes there are late side effects from radiotherapy in patients.
Radiation-induced pneumonitis is the most common late-act lung symptom. This may occur after radiotherapy has been carried out on lung tissue. Coughing, shortness of breath, and fever are the symptoms. Pneumonitis induced by radiation occurs 1 to 6 months after radiotherapy. In order to alleviate the symptoms, Cortisone is used. Usually, the symptoms disappear completely.
Another late effect that may arise in the lungs is radiation induced pulmonary fibrosis.
Brain radiotherapy patients may experience a syndrome that includes fatigue and headaches 2 to 6 months after treatment. Radiotherapy can also cause damage to the heart and blood vessels that may lead to the development of arterial disease years or decades later.
