Intensity modulated radiation therapy (IMRT) is like 3D-CRT, but it also changes the strength of some of the beams in certain areas. This allows the radiation oncologist to adjust the position of the patient or re-focus the radiation as needed to be sure that the radiation beams are focused on the tumor exactly and that exposure to normal tissues is limited. Image guided radiation therapy (IGRT) is a form of 3D-CRT where imaging scans (like a CT scan) are done before each treatment. This helps to reduce radiation damage to normal tissues and better kill the cancer by focusing the radiation dose on the tumor's exact shape and size. Three-dimensional conformal radiation therapy (3D-CRT) delivers radiation beams from different directions designed to match the shape of the tumor. Your cancer care team will help decide how much radiation is needed to treat your cancer and how often you need to get it. But some people may need to go to the treatment center twice a day for a fewer number of weeks. Usually, they visit the treatment center every weekday (Monday through Friday) for a certain number of weeks.

Most people get external radiation therapy over many weeks. These machines focus the radiation on the exact location where it needs to be, so that normal tissues are affected as little as possible.Įxternal radiation is usually done during outpatient visits to a hospital or treatment center. Radiation technology allows the very careful delivery of external beam radiation therapy. A machine is used to aim high-energy rays (or beams) from outside the body into the tumor. External radiation (or external beam radiation) is the most common type of radiation therapy used for cancer treatment.

180 lead tc accurate 5