Modern radiation therapy
Radiation therapy for children and teenagers has advanced a great deal over the years.
In the past, the size of the area on the body that the radiation was pointed at had to be bigger. This meant that large amounts of healthy cells had to be included and were damaged when treating cancer and tumours. Today, modern radiation techniques allow doctors to define the area to be treated much more accurately so that it is much smaller and damages fewer healthy cells. Through the use of better imaging technology, we can now make a much more accurate plan to guide the radiation beams directly at the tumours.
You may hear terms like "3D radiation", "intensity modification radiation therapy", and "image guided radiation therapy". They are all methods of performing radiation to try to get as many tumour cells and as few healthy cells as possible. Most of the machines used for radiation therapy look a lot like X-ray, CT and MRI machines you may have seen before.
Unfortunately, even with the best available imaging technology, it is still impossible to identify the exact outer edge of a tumour. As a result, some normal tissue may need to be included in the treatment area to make sure all the tumour cells are treated. Fortunately, most normal cells are less sensitive to the effects of radiation, and they can recover more easily than tumour cells from radiation damage.
Total body irradiation
With total body irradiation, the radiation is given over the entire body instead of just targeting a small area where the cancer is located. This kind of radiation is specifically used to wipe out your bone marrow in order to treat certain kinds of cancer (such as leukemia). Total body irradiation is used before some bone marrow transplants. In these cases, the radiation is given in separate small treatments (fractions) twice each day, for three days.
