Diagnostics

What Is Radiotherapy? What Is Radiation Therapy?

Radiotherapy is also known as radiation therapy, radiation oncology and XRT. It is used for treating cancer, thyroid disorders and some blood disorders. Approximately 40% of cancer patients undergo some kind of radiotherapy. It involves the use of beams of high-energy X-rays or particles (radiation) to destroy cancer cells. Radiotherapy works by damaging the DNA inside the tumor cells, destroying their ability to reproduce. According to Medilexicon"s medical dictionary, radiation oncology is "1. the medical specialty concerned with the use of ionizing radiation in the treatment of disease; 2. the medical specialty of radiation therapy; 3. the use of radiation in the treatment of neoplasms (tumors). Radiotherapy can be used for different reasons *Total cure Interesting articles What is radiation? What is cancer? What causes cancer? What is chemotherapy? What are the side effects of chemotherapy? What is skin cancer? What is melanoma? What is anal cancer? What causes anal cancer? What is colorectal cancer? What causes colorectal cancer? What is colon cancer? What causes colon cancer? What is lymphoma? Lymphoma causes and treatments. What is leukemia? What causes leukemia? What is breast cancer? What is function of the lymph nodes? To cure the patient by completely destroying the tumor. *To alleviate symptoms Radiotherapy is often used to relieve pain in more advanced cancers. *Neo-adjuvant radiotherapy (before surgery) If a tumor is large, radiotherapy can shrink it, making it easier and less harmful to then surgically remove it. *Adjuvant radiotherapy - given after surgery The aim is to eliminate the cancer cells that remained behind. Doctors at St Jude Children"s Research Hospital, TN, USA reported that aggressive surgery followed by targeted radiotherapy is the optimal means by which a rare form of childhood brain cancer (Ependymoma) should be treated, as it significantly improved survival rates, compared to children who received surgery alone. *Combination therapy - radiotherapy combined with another type of therapy In some cases, chemoradiation - radiotherapy combined with chemotherapy - is more effective. A Canadian-European study found that giving patients with glioblastoma the chemotherapy drug temozolomide in combination with radiotherapy increases their survival rate, compared with those receiving radiotherapy alone, and this improvement persists for up to 5 years. Radiotherapy combined with hormone therapy has been shown to significantly reduce mortality in men with prostate cancer, according to The Prostate Cancer Charity, UK. *Total body irradiation (TBI) The whole body receives radiation. This may be used for leukemia or lymphoma before a bone marrow transplant - the aim is to destroy the bone marrow cells. Researchers from the Institut Louis Bugnard found that TBI may damage fat tissue. Sometimes radiotherapy is an effective alternative to surgery Researchers in Leeds, England, reported that radiotherapy is as effective as surgery in treating bladder cancer. They found that survival rates for patients who underwent a radical cystectomy (surgical removal of the bladder) were the same as for those who just received radiotherapy. When to administer radiation therapy? Some cancers develop faster than others. Whether to administer radiotherapy promptly often depends on this, as well as other characteristics of some cancers. For cancers, such as breast and head and neck cancers, the risk of the cancer recurring increases if radiotherapy is delayed, according to scientists at the Cancer Research Institute, Kingston, Ontario, Canada, and Cross Cancer Institute, Edmonton, Alta, Canada. How long does a course of radiation last? A course of radiotherapy may last from less than a day to a number of weeks. According to the National Health Service (NHS), UK, most patients will undergo one fraction (session) per day from Monday to Friday with a break at the weekend to allow the body to recuperate. What is "a fraction" in radiation? In each case the radiologist will decide what the full dose for the treatment should be. This cannot be given all in one go because it would harm the patient. So, it is divided up into fractions. During each session the patient will receive a fraction of the total dose. A session is often called a fraction. Types of radiation therapies External beam radiation See our specialized news channels Radiology / Nuclear Medicine News Asbestos / Mesothelioma News Breast Cancer News Cancer / Oncology News Colorectal Cancer News Lung Cancer News Lymphoma / Leukemia News Melanoma / Skin Cancer News Ovarian Cancer News Pancreatic Cancer News Prostate Cancer News High-energy beams come from a device outside the human body - this could be in the form of X-rays, cobalt irradiation, electrons and protons. The beams are aimed at a specific point in the body - where the tumor is. The radiation destroys the genetic material that controls how cancer cells grow and divide. A certain number of healthy cells are also damaged by this kind of treatment. The aim is to hit as many cancer cells as possible while damaging the minimum number of healthy ones. Most damaged healthy cells are able to repair themselves. The patient will feel no pain during each session. However, he/she may experience temporary side-effects later on, which may include pain or discomfort. External radiation may be given in other forms: *Conformal radiotherapy - the standard external radiotherapy machine is used, but metal blocks are placed in front of the radiation beam. This changes the beam"s shape. The aim is to make the beam "conform" to the shape of the tumor. If the beam is shaped like the tumor fewer healthy cells will be damaged when doses are high. This results in side effects being less severe and not so long-lasting. *Intensity modulated radiotherapy (IMRT) - computers regulate the machine"s emission so that very precise radiation doses are aimed at certain parts of the tumor. A 3-D scan of the tumor is done beforehand so that the radiologist can work out the exact intensity of the dose according to the tumor"s shape. The tumor receives a high dose of radiation, leaving nearby healthy cells exposed to very low doses. Patients undergoing IMRT tend to have fewer side effects, compared to those on standard treatments. US scientists reported in a study that the application of modulated radiotherapy in the treatment of bowel cancer can enhance the results obtained by means of other conventional therapies without increasing toxicity. What happens during an external radiation session? Unless the patient is also receiving chemotherapy as well, or is not well, he/she will go home as soon as the session is over. The patient will be positioned on a treatment table and the radiotherapy machine will direct the high-energy rays at a specific part of the body. While this happens it is important to keep completely still so that the targeting is as perfect as possible. The radiology team will be in another room. They can see the patient at all times and the patient can communicate with them. They stay in another room because a lifetime of light radiation exposure would gradually build up eventually start to harm them. The whole process should not take more than a few minutes. Internal Radiotherapy The radiotherapy is given from inside the body. The patient may drink a liquid which is absorbed by cancer cells, or radioactive material may be placed near the tumor. The two types of internal radiation therapies include: *Radioactive liquids - these are either consumed as a drink or injected into the patient. For cancers of the blood the liquid will contain phosphorous, secondary bone cancer patients will be given strontium, while iodine will be used for thyroid cancer. *Radioactive implants (brachytherapy) - this may be in the form of metal seeds (pellets), tubes or wires. They are placed very near to the tumor. The implant may stay in the body for just few minutes or a number of days - this depends on the type of cancer and tumor. There are cases when the implants are never taken out. If the patient is hospitalized and has radioactive implants or liquids, the hospital will take measures to protect staff and visitors from radiation exposure. Some patients may become alarmed at these measures; wondering about the safety of what they have subjected themselves to. It is important to remember that the high radiation doses are aimed at the cancer, while the other healthy cells receive a much lower dose - even if some are damaged, most will recover. The medical team has determined that the benefits of the radiotherapy are greater than the risks. As soon as an implant is taken out the patient has no more radioactivity in his/her body - it does not linger. The radioactivity in liquid treatments takes a few days to disappear. In both cases, when the radiation is gone the patient is not a risk to anyone around him/her. In most countries the patient will stay in hospital until the implant is removed or the effects of the liquid have gone. Those with permanent implants have such a low dose that they are not usually a risk to others. The radiology team will advise the patient on safety steps. Some studies have indicated that internal radiotherapy results in a better quality of life for the patient whose cancer is in the pelvic region, compared to external therapy. Dutch researchers said that this quality of life benefit would be an important factor to take into account when comparing the risks and benefits of using vaginal brachytherapy or external beam pelvic radiotherapy after surgery for endometrial cancer patients. Combining magnetic resonance imaging (MRI) with radiotherapy Real-time image-guided radiotherapy, combining radiation treatment with non-invasive MR imaging, is far less harmful for patients as it leaves less healthy tissue damaged and gives radiation oncologists the possibility

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