When Is Internal Radiation Therapy Used?
Your doctor may decide that a high dose of radiation given to a small area of your body is the best way to treat your cancer. Internal radiation therapy allows the doctor to give a higher total dose of radiation in a shorter time than is possible with external treatment.

Internal radiation therapy places the radiation source as close as possible to the cancer cells. Instead of using a large radiation machine, the radioactive material, sealed in a thin wire, catheter, or tube (implant), is placed directly into the affected tissue. This method of treatment concentrates the radiation on the cancer cells and lessens radiation damage to some of the normal tissue near the cancer. Some of the radioactive substances used for internal radiation treatment include cesium, iridium, iodine, phosphorus, and palladium.

Internal radiation therapy may be used for cancers of the head and neck, breast, uterus, thyroid, cervix, and prostate. Your doctor may suggest using both internal and external radiation therapy.

In this booklet, 'internal radiation treatment' refers to implant radiation. Health professionals prefer to use the term "brachytherapy" for implant radiation therapy. You may hear your doctor or nurse use the terms, interstitial radiation or intracavitary radiation; each is a form of internal radiation therapy. Sometimes radioactive implants are called "capsules" or "seeds."

How Is the Implant Placed in the Body?
The type of implant and the method of placing it depend on the size and location of the cancer. Implants may be put right into the tumor (interstitial radiation), in special applicators inside a body cavity (intracavitary radiation) or passage (intraluminal radiation), on the surface of a tumor, or in the area from which the tumor has been removed. Implants may be removed after a short time or left in place permanently. If they are to be left in place, the radioactive substance used will lose radiation quickly and become non-radioactive in a short time.

When interstitial radiation is given, the radiation source is placed in the tumor in atheters, seeds, or capsules. When intracavitary radiation is used, a container or applicator of radioactive material is placed in a body cavity such as the uterus. In surface brachytherapy the radioactive source is sealed in a small holder and placed in or against the tumor. In intraluminal brachytherapy the radioactive source is placed in a body lumen or tube, such as the bronchus or esophagus.

Internal radiation also may be given by injecting a solution of radioactive substance into the bloodstream or a body cavity. This form of radiation therapy may be called unsealed internal radiation therapy.

For most types of implants, you will need to be in the hospital. You will be given general or local anesthesia so that you will not feel any pain when the doctor places the holder for the radioactive material in your body. In many hospitals, the radioactive material is placed in its holder or applicator after you return to your room so that other patients, staff, and visitors are not exposed to radiation.

How Are Other People Protected From Radiation While the Implant is in Place?
Sometimes the radiation source in your implant sends its high energy rays outside your body. To protect others while you are having implant therapy, the hospital will have you stay in a private room. Although the nurses and other people caring for you will not be able to spend a long time in your room, they will give you all of the care you need. You should call for a nurse when you need one, but keep in mind that the nurse will work quickly and speak to you from the doorway more often than from your bedside. In most cases, your urine and stool will contain no radioactivity unless you are having unsealed internal radiation therapy.

There also will be limits on visitors while your implant is in place. Children younger than 18 or pregnant women should not visit patients who are having internal radiation therapy. Be sure to tell your visitors to ask the hospital staff for any special instructions before they come into your room. Visitors should sit at least 6 feet from your bed and the radiation oncology staff will determine how long your visitors may stay. The time can vary from 30 minutes to several hours per day. In some hospitals a rolling lead shield is placed beside the bed and kept between the patient and visitors or staff members.

What Are the Side Effects of Internal Radiation Therapy?
The side effects of implant therapy depend on the area being treated. You are not likely to have severe pain or feel ill during implant therapy. However, if an applicator is holding your implant in place, it may be somewhat uncomfortable. If you need it, the doctor will order medicine to help you relax or to relieve pain. If general anesthesia was used while your implant was put in place, you may feel drowsy, weak, or nauseated but these effects do not last long. If necessary, medications can be ordered to relieve nausea.

Be sure to tell the nurse about any symptoms that concern you. In Section 4, "Managing Side Effects," you will find tips on how to deal with problems that might occur after implant therapy.

How Long Does the Implant Stay in Place?
Your doctor will decide the amount of time that an implant is to be left in place. It depends on the dose (amount) of radioactivity needed for effective treatment. Your treatment schedule will depend on the type of cancer, where it is located, your general health, and other cancer treatments you have had. Depending on where the implant is placed, you may have to keep it from shifting by staying in bed and lying fairly still.

Temporary implants may be either low dose-rate (LDR) or high dose-rate (HDR). Low dose-rate implants are left in place for several days; high dose-rate implants are removed after a few minutes.

For some cancer sites, the implant is left in place permanently. If your implant is permanent, you may need to stay in your hospital room away from other people for a few days while the radiation is most active. The implant becomes less radioactive each day; by the time you are ready to go home, the radiation in your body will be much weaker. Your doctor will advise you if there are any special precautions you need to use at home.

What Happens After the Implant Is Removed?
Usually, an anesthetic is not needed when the doctor removes a temporary implant. Most can be taken out right in the patient's hospital room. Once the implant is removed, there is no radioactivity in your body. The hospital staff and your visitors will no longer have to limit the time they stay with you.

Your doctor will tell you if you need to limit your activities after you leave the hospital. Most patients are allowed to do as much as they feel like doing. You may need some extra sleep or rest breaks during your days at home, but you should feel stronger quickly.

The area that has been treated with an implant may be sore or sensitive for some time. If any particular activity such as sports or sexual intercourse cause irritation in the treatment area, your doctor may suggest that you limit these activities for a while.