Understanding Radiation, X-Rays, Mammograms, & CT Scans

As with chemotherapy, certain forms of medicalthese women and generally recommend that they
radiation can lead to an increased risk of cancer. Thehave vigilant lifetime screening for breast cancer.
benefits of using these types of medical radiation,However, most studies of individuals with Hodgkin's
however, generally far outweigh the risks associateddisease have found no increased breast cancer risk
with them.among women who receive radiation at 30 years and
Radiation Therapy: Radiation therapy usesolder.
high-energy ionizing radiation to destroy cancer cellsX-rays and Mammography: Many people are
and treat or control cancer. Radiation therapy'sconcerned about their exposure to x-rays. X-rays
cancer-causing potential was recognized many years(including mammograms, x-rays of the breast) use
ago. In fact, much of our knowledge about ionizingdoses of radiation that are many times lower than
radiation has come from studying the survivors ofthose used in radiation therapy. As with radiation
the atomic bombs and their radiation in Japan, fromtherapy, studies in the past have shown that there
workers' occupational exposure to radiation, and fromappears to be some risk in receiving many x-ray
patients treated with radiation therapy for malignantexaminations, particularly for children who have
and nonmalignant disease. Despite being relativelymultiple x-rays. The level of radiation in modern
rare, the development of a second cancer is morex-rays is much lower than that used even 25 years
common among those who receive radiation therapyago and poses much less of a risk. While it's a good
than those who do not.idea to minimize repeat exposures whenever
It's a fine balance. You have to weigh the risk againstpossible, especially in children, it's important not to
the medical benefit. If you have a cancer and you'reavoid necessary x-rays.
going to be treated with radiation, you should beCT Scans: Computed tomography (CT) scans use
concerned about the risk of developing a secondlarger doses of radiation than those found in
cancer, but not to the extent that you turn downconventional x-rays. Again, concern has been raised
possible treatment. On the other hand, you shouldover the possibility of an increased cancer risk in
certainly discuss the treatment options fully with yourchildren who receive multiple CT scans. Ways to
doctor.lower radiation doses without compromising medical
Most cases of leukemia related to radiation exposurevalue are encouraged.
develop within a few years of exposure, peaking atAnother potential source of exposure to radiation are
five to nine years then slowly declining. Most otherwhole-body CT scans, which some people are now
forms of cancer do not occur until ten years afterrequesting as part of a regular health checkup as a
radiation exposure, and some cancers are diagnosedway to screen for cancer and other diseases. Many
even fifteen or more years later. Radiation-relatedgroups, including the PDA, have expressed concern
leukemia risk depends on a number of factors, suchover this practice because there is little evidence of
as the amount of radiation received, the percentageits usefulness, and it exposes people to unnecessary
of bone marrow exposed to radiation, and whetherradiation. Sometimes CT scans are available in
the patient was also treated with chemotherapy.shopping malls. They are advertising for healthy
Studies of radiation-related breast cancer have foundpeople to come in and get whole-body scans. This is
the greatest risk in women who were irradiated asunnecessary and inappropriate.
children and adolescents for other conditions. (TheHowever, whole-body CT scans do have their place.
most common reason for adolescents to have chestThey can save the lives of accident victims who
radiation is Hodgkin's disease, a type of lymphoma.)need quick evaluation to determine if they have a
Oncologists (doctors specializing in cancer treatment)ruptured spleen or punctured lung. They are also
know about the increased risk of breast cancer ineffective in diagnosing some chronic conditions.