How does radiation therapy work?
All of your cells, both normal and malignant, must reproduce in order to survive. In order to reproduce, cells must have healthy genetic material, called DNA. The radiation given to patients damages the DNA in cancer cells. When cancer cells try to reproduce with their damaged DNA, they die.
Why does radiation therapy cause side effects?
Healthy normal cells are unavoidably treated by the radiation. The damage to normal cells causes radiation side effects. Even though some normal tissue is injured during radiation treatment, this tissue usually recovers while cancer cells are killed. Radiation side effects are strictly limited to those tissues that are actually being treated. For example, a patient treated with radiation for prostate cancer or breast cancer won't experience hair loss from the head area.
Why does radiation therapy take so long?
Normal cells are able to repair DNA damage far better after small doses of radiation than after large doses. Dividing a large total dose of radiation into smaller daily doses delivered over several weeks – rather than giving a few massive doses in several days – minimizes side effects. Between each of your daily doses, the normal cells are repairing their damaged DNA, resulting in fewer side effects. Although it seems very inconvenient to give treatment over such a long period of time, this is the only way to deliver enough total radiation to permanently destroy your cancer without also permanently hurting normal tissues.
Why do I feel fatigued?
Some patients undergoing radiation therapy feel fatigue during treatment. There are different reasons for this fatigue, depending upon the part of the body being treated. Remember that fatigue is temporary and, in most cases, a patient will recover to his or her pre-treatment level within a few weeks of the completion of treatment.
Will I become radioactive?
The vast majority of our patients are treated with external beam radiotherapy – a radiation emitted from a machine outside of the body. At no time does the body become radioactive. Patients under treatment with external radiotherapy can interact with family and loved ones with the complete assurance that they are not placing anyone at risk.
Few patients are treated with radioactive implants that do emit radiation during the treatment period. These patients are usually kept in the hospital during treatment and are prevented from exposing others to radiation. These patients emit no further radiation when the implants are removed.
How long will the side effects last?
Treatment-induced side effects result from radiation damage to normal organs during radiation. Those organs that can replace radiation-damaged cells – such as the skin, intestine and bone marrow – experience only temporary side effects. Other organs such as the salivary glands usually cannot replace cells damaged during the treatment of head and neck cancers. The side effect of mouth dryness is therefore frequently permanent. It is best to consult with your radiation oncologist as to which radiation-induced side effects are temporary and which are permanent.
Will my hair fall out during radiation therapy?
If a patient does not receive radiation to the scalp, he or she will not lose hair on the head. Radiation only affects those parts of the body that receive radiation. Patients that do receive radiation to the scalp often have regrowth of their hair, although it may take several months.
Can I continue to take my vitamins and mineral supplements during my treatment?
In general, patients are encouraged to take vitamin or mineral supplements they may have taken prior to radiation therapy. The only exception to this is vitamin E, which should be discussed individually with your physician. Inform your physician of all medications and vitamins that you are taking.
Do I need to stay out of the sun or avoid taking sauna baths?
Proper protection from the sun's damaging UV radiation is important for everybody. For radiation therapy patients, it is particularly important to keep the part of the body receiving radiation covered and protected from the sun's rays. Areas of the body not treated by radiation are no more sensitive to the sun's rays than before radiation treatment. All patients should avoid heated saunas and hot tubs during radiation therapy because skin can be especially sensitive to heat. Patients should consult with their physicians at their first follow-up visit before they resume these types of heated baths.
Can I receive radiation treatments more than once?
Generally a patient can receive radiation therapy to a given area only once. This is because further radiation therapy to that same area might cause unacceptable side effects or permanent damage. Occasionally, if the radiation tolerance has not been exceeded, someone can receive more radiation even to an area that was already treated. Because the effects of radiation are local, most patients can receive radiation to another part of the body just as if they had no previous radiation.
If my blood count is low, can I still receive radiation treatments?
If you are receiving radiation treatments that include a significant portion of your active bone marrow, the radiation will probably be delayed for several days until your blood count comes up. This occurs most commonly when the spine or pelvis is being treated. When one area of bone marrow is treated with radiation, the other areas can usually produce enough extra blood cells that the counts will not drop significantly.
How does taking radiation and chemotherapy at the same time affect my body?
For certain types of cancer, a combination of radiation and chemotherapy is more effective than either one alone. Chemotherapy is a systemic treatment that acts on the whole body as it travels through the bloodstream. When it is given at the same time as radiation, it often increases the effect of radiation on cancer cells.
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