Frequently Asked Questions

What is radiation therapy?

Radiation therapy (also called radiotherapy, x-ray therapy or irradiation) is a painless treatment, similar to an x-ray. It uses high energy x-rays to injure the DNA of cancer cells so that they are unable to grow or to repair themselves. Cancer cell populations often grow at a faster rate than do normal cell populations and this makes many cancers sensitive to radiation. Radiation also affects normal, healthy cells but, unlike cancer cells, these are often able to recover from radiation damage.

Radiation therapy can be used many ways:

• as a treatment on its own
• as a way of shrinking tumors prior to surgery, in order to improve the chances that the surgery will be successful
• after surgery to make sure that all tumor cells are destroyed
• in combination with chemotherapy

What is brachytherapy?

Brachytherapy is a form of radiation treatment in which tiny pellets or "seeds" containing radioactive material, such as Iodine-125, are implanted directly into the body to fight cancer. Over time, a calculated amount of radiation leaks out of the pellets, and into the surrounding tissue. Sometimes pellets are placed right inside the tumor tissue, as in the case of prostate cancer. Other times, brachytherapy is used to kill any remaining cancer cells left over after a tumor is surgically removed from the body. In this case, the pellets may be placed inside a body cavity, such as the uterus, vagina, or airway. Brachytherapy can deliver relatively high doses of radiation to the tumor site while minimizing the risk to adjacent organs.

What is stereotactic radiosurgery?

This technique delivers a well-defined beam of radiation to tumor cells. Because the technique is so precise, and normal tissue is avoided, a high dose can be delivered in a single treatment. Radiosurgery is a non-invasive procedure (that is, no cutting of tissue is involved), and is often used when the area to be treated cannot be safely reached by traditional surgery. Stereotactic radiosurgery is often used as a treatment for patients with abnormal blood vessels in the brain (arteriovenous malformations), brain tumors, or other special tumors of the head and neck regions. Stereotactic radiation therapy is accurate to one millimeter or less, does not require surgery, and can be done on an outpatient basis.

How does radiation therapy differ from chemotherapy in cancer treatment?

Radiation therapy is considered to be a "local" treatment, meaning that it affects only the area of the body to which it is directed. Radiation can be aimed at the part of the body affected by cancer with great accuracy, and so exposure of normal tissue is minimized. Chemotherapy differs because it is a systemic therapy. This means that the anticancer medicines travel throughout the whole body, rather than being confined to one area. Unlike radiation therapy, chemotherapy can reach cancer cells that may have spread to other parts of the body. In many cases, radiation therapy and chemotherapy are both part of a plan to treat a patients cancer.

Why can't all cancers be treated with radiation therapy?

Radiation therapy can be part of a treatment plan for most types of cancers, but it works better for some than others. Sometimes, radiation therapy is used instead of surgery to attack a tumor, as in prostate cancer. In many cases, radiation therapy is used in combination with surgery and chemotherapy. Surgery removes the tumor, and then radiation therapy is given to a larger, adjoining area to destroy any cancer cells that were not removed during surgery. Chemotherapy is then used to eliminate cancer cells that might have spread to the rest of the body. Radiation therapy can also be effective against small tumors that cannot be removed through surgery (i.e., bone or brain tumors that have spread). Cancers like leukemia that affect blood and bone marrow throughout the body are generally not initially treated with radiation therapy, but patients with these cancers may receive prophylactic (preventive) radiation therapy to the brain or spinal canal to treat cancer cells that may be present, but not yet detected.

What is the difference between external beam radiation and brachytherapy?

External beam radiation is treatment given from a machine at a distance from the body. Usually, this machine is a linear accelerator. The patient lies in a pre-determined position on the treatment table, and trained radiation therapists identify the area to be treated. Some external beam treatments can be focused on a very small area, and a higher dose with fewer fractions can be given. Stereotactic radiation therapy is focused treatment to a part of the brain and can be given in one or several doses. Brachytherapy (which DFCI patients receive at Brigham and Women's) is the placing of a radioactive source, or implant, within the body. The implant may be placed in a tumor or body cavity for a limited or indefinite period. Brachytherapy may be given at a high dose rate for some cancers, such as gynecological or lung cancers, or at a low dose rate, as in prostate cancer.

How does a patient prepare for radiation treatment?

Although radiation therapy is a painless procedure, patients can still take several steps to ready themselves for it. Therapy that takes place five days a week for several weeks can cause fatigue, so patients should get sufficient rest before, during, and after their treatments. Eating a balanced diet and informing nurses and doctors of any allergies or medication use is also important. On days they are scheduled to receive radiation therapy, patients should wear loose, soft cotton clothing over the treatment area. And, since the skin in this area will become more sensitive, it should not be scratched, rubbed, scrubbed, or exposed to the sun.

What are some side effects associated with radiation therapy?

Side effects for radiation differ depending on the patient and treatment type. You should discuss with your physician/nurse team the anticipated side effects of your specific treatment. As with chemotherapy, the most common adverse reaction to radiation is fatigue. The stress associated with daily hospital visits, coupled with the effects of this therapy on non-cancerous cells, often causes fatigue to set in after a few weeks. Patients are advised to "listen to their body" by resting as much as necessary and decreasing their workload. Red, irritated skin in the treatment area is another regular complaint; in addition to avoiding the urge to rub or scratch, patients can combat this side effect by washing with lukewarm water and mild soap. Although hair loss is far more common with chemotherapy, patients who receive radiation to their head can lose some or all of the hair on their scalp.

What follow-up care is necessary after completing radiation treatment?

Follow-up care after radiation depends on the type of cancer treated, as well as the number of radiation sessions patients have undergone. Additional cancer treatment, rehabilitation, and counseling are all follow-up options, and regular physician visits are also important so that side effects can be monitored and any recurrent disease can be caught at an early stage. Although a radiation oncologist often participates in follow-up care, some patients are referred to their original doctor, a surgeon, or a medical oncologist for such visits. Patients should also monitor their own situation in the weeks following therapy by taking steps to avoid skin irritation in the treatment area and by contacting their doctors if they experience any of the following: persistent pain (especially in one area); new or unusual lumps, bumps, or swelling; nausea, vomiting, diarrhea, or loss of appetite; unexplained weight loss; a fever or cough that won't go away; unusual rashes, bruises, or bleeding; or anything else they have been warned about or that troubles them.

What is simulation?

Simulation is part of the radiation therapy planning phase that takes place in a separate appointment before any radiation treatment begins. The patient is asked to lie very still on a table for up to an hour, and may need to wear a specially fitted mask, frame or board to immobilize the part of the body that is being mapped for treatment. While the patient lies still, a radiation therapist (a specially trained technologist) under the supervision of the radiation oncologist uses a special x-ray machine to pinpoint the treatment area, sometimes called the treatment portal or field. This is the exact place in the body where the radiation will be aimed. Ink lines are usually drawn on the skin to mark the area to be treated. Tattoos (tiny permanent skin markings the size of freckles) may also be placed at the time of simulation.

Do radiation therapy patients have to worry about being radioactive?

Patients receiving external beam radiation therapy are NOT radioactive and do not need to take special precautions to protect others from radiation. The radiation that they receive does not stay in the body and the treatments are given in special rooms that do not allow the radiation to escape.

With internal radiation therapy, or brachytherapy, tiny containers of radioactive material are placed inside the body. Patients who receive a temporary implant only need to take special precautions to avoid exposing others to radiation during the time that the implant is in place. In this case, the radiation therapy team will give more specific instructions. If an overnight stay in the hospital is required during implant therapy, the patient will probably need to stay in a private room. Although the nurses and other care-providers will not be able to spend a long time in the room, they will give all of the care that is needed. There will also be limits on visitors while a temporary implant is in place.

Permanent implants use weaker radiation, and patients can usually be discharged home after the procedure. If you have permanent implants, such as seed implants, you may need to refrain from close contact with other people for a few days while the radiation is most active.

Is radiation therapy safe?

The radiation that damages or destroys cancer cells can also injure or kill normal cells. It is this harm to normal cells that can cause treatment side effects. However, most side effects of radiation treatment are well known and, with the help of your doctor and nurse, easily treated. Radiation therapy is generally considered to be safe because the risk of side effects is usually less than the benefit of killing cancer cells. High-tech equipment and careful treatment planning ensure that the radiation is directed at the cancer and avoids healthy tissue as much as possible. In addition, every treatment plan is checked and re-checked by members of the treatment team and by computer monitoring equipment throughout the course of treatment.

Some patients worry that radiation therapy will cause cancer years after treatment. Although there is a very small chance of this, the risk is usually outweighed by the benefits of receiving the treatment and killing cancer cells. Your doctor will not advise you to have any treatment unless the benefits — control of disease and relief from symptoms — are greater than the known risks.

How does the patient know if the radiation worked?

Once radiation treatments are complete, the radiation oncologist will monitor the results of the therapy at regularly scheduled follow-up visits. During these checkups the doctor will examine the patient, note any changes in symptoms, and most likely order some lab tests and radiology studies (x-rays, CT scans, MRI scans, PET scans) to see if the cancer has responded to treatment. Because radiation works by making cancer cells unable to effectively divide and grow, it is often impossible see the cells dying until they attempt to divide. The effects of radiation treatment on cancer can occur over weeks and months after treatment stops.

Some types of cancers can also be measured in the blood with a "tumor marker". This is a chemical substance that is either made by the tumor or produced by the body in response to the tumor. In some cases, blood tests can show if the tumor marker has decreased, indicating that the tumor has shrunk. You should talk with your doctor or nurse about how your response to radiation therapy will be measured.