The Gamma radiation intensity decreases exponentially with the depth of penetration. They damage the cancerous cells' DNA, causing them to die or reproduce more slowly. The image represents the technique called Radiotherapy to treat Gamma Rays. They do this by targeting the cancer cells with a beam of radiation then rotating the beam like it is shown in the picture.
Normal cells in the radiotherapy area may also be damaged but they can usually repair themselves. Another result of the use of gamma rays could be an abnormal mitosis, implies a change of DNA, which leads to genetic damage and to DNA mutations in other cells that survive the radiation.
This may lead to the development of a second cancer. A small amount of radioactivity is administered usually through intra-venous injection. The radioactive chemical is chosen so that e. Then, a special device named a gamma-camera detects the gamma photons stemming from the body, creates images and allows the physician to locate the cancer cells.
The radiographer puts a detector around the body to detect any gamma rays that pass out of the patient's body Radioisotopes with short half-lives are chosen to make sure that the tracer does not stay radioactive in the body for long periods. The free radicals made inside a cell's nucleus can cause damage to the cell's components and breaks in the DNA structure.
The cell cannot longer reproduce and the result is cell death. Whoever comes into contact with gamma radiation, must be very careful. Preparation for radiation therapy is focused on targeting the radiation dose to the cancer as precisely as possible to minimize side effects and avoid damaging normal cells. Imaging tests may be used to help determine the exact shape and location of your tumor and define its boundaries. Your doctor will give you specific instructions based on the type of exam being performed.
An increasing number of patients have their cancers treated successfully using radiation therapy. Modern technology has combined the use of three-dimensional imaging technology, computerized treatment planning and high-energy x-ray machines to make more precise treatment possible.
Professionals involved in radiation therapy treatment include:. More than half of cancer patients are treated with radiation at some time during their course of treatment. Radiation therapy is the use of high-energy radiation to treat cancer. A radiation oncologist may use radiation to cure cancer or to relieve a cancer patient's pain or alleviate other symptoms due to the cancer.
Radiation therapy works because the radiation destroys the cancer cells' ability to reproduce, and the body naturally gets rid of these cells. Radiation affects cancer cells by damaging their DNA, so that the cancer cells can no longer divide and grow.
Radiation is most effective at killing cells that are actively dividing. Cancer cells are more vulnerable to radiation for two reasons:. A radiation oncologist may use external beam radiation therapy or brachytherapy to treat cancer. External beam radiation therapy can be generated by a linear accelerator a machine that accelerates electrons to produce x-rays or gamma rays. Proton therapy is another form of external beam radiation therapy that uses cyclotrons or synchrotrons to produce charged atoms that destroy tumors.
Radiation therapy given by radioactive sources that are put inside the patient is called brachytherapy. The radioactive sources are sealed in needles, seeds, wires, or catheters, and implanted directly into or near a tumor on a temporary or permanent basis. Brachytherapy is a common treatment for cancers of the prostate , uterus, cervix or breast. Some cancer patients may be treated with radiation as their primary treatment. In some cases, radiation therapy is given at the same time as chemotherapy.
Chemotherapy used with radiation therapy can improve the local response and reduce metastatic disease. In other cases, radiation therapy is given before neoadjuvant treatment or after adjuvant treatment surgery. The staff working with the radiation oncologist including physicists and dosimetrists use sophisticated computers to design the details of the exact radiation plan that will be used.
After approving the plan, the radiation oncologist authorizes the start of treatment. On the first day of treatment, and usually at least weekly after that, many checks are made to ensure that the treatments are being delivered exactly the way they were planned.
Radiation doses for cancer treatment are measured in a unit called a gray Gy , which is a measure of the amount of radiation energy absorbed by 1 kilogram of human tissue. Different doses of radiation are needed to kill different types of cancer cells.
Show More. Login Register. Enjoying our content? Thanks for visiting Oncology Nurse Advisor. If you wish to read unlimited content, please log in or register below. Registration is free. Register for free and gain unlimited access to:. What is radiation therapy? Continue Reading. Please login or register first to view this content.
0コメント