Radiation: External Beam (Stevie JoEllie's Cancer Care Fund )

Radiation: External Beam

Contents

1 External Beam Radiation Facts
2 Possible Side Effects
3 Mouth Care
4 Follow-Up Testing
5 Testing may include:
6 Other tests sometimes used:

External beam radiation is sometimes given as an adjuvant treatment in addition to the primary treatment, or as a curative treatment when the cancer cannot be removed by surgery, or as a palliative approach to relieve symptoms and improve quality of life.

External Beam Radiation Facts

External beam radiation therapy involves a series of daily outpatient treatments to accurately deliver radiation to the cancer.

Painless radiation therapy treatments are delivered in a series of daily sessions. Radiation treatments take only a few minutes, but each session takes about half an hour to get checked in, change clothes, get into position and receive the radiation. For some conditions, radiation is given twice a day, with a four to six hour gap between treatments.

Treatments are usually scheduled Monday through Friday, for five to eight weeks. However, your radiation oncologist may schedule your treatments more or less often depending on your cancer.

3-dimensional conformal radiotherapy (3D-CRT) combines multiple radiation treatment fields to deliver precise doses of radiation to the affected area. Tailoring each of the radiation beams to accurately focus on the patient's tumor allows coverage of the cancer while at the same time keeping radiation away from nearby healthy tissue.

Intensity modulated radiation therapy (IMRT) is a form of 3D-CRT that further modifies the radiation by varying the intensity of each radiation beam. This technique allows a precise adjustment of radiation doses to the tissue within the target area. IMRT may allow doctors to direct a higher radiation dose to the affected area and keep more radiation away from nearby healthy tissue.

To help you keep still during treatment, your doctor may use a plastic head or shoulder mask. These devices are specially fitted for you and are painless to use.

Possible Side Effects

Side effects of radiation therapy are limited to the area that is receiving treatment.

Side effects can include redness of the skin, sore throat, dry mouth, alteration of taste, pain on swallowing and possible hair loss in the treated area. Fatigue is also very common.

Side effects are different for each patient. Medications and nutritional supplements may be prescribed to make you as comfortable as possible.

If at any time during your treatment you feel discomfort, tell your doctor or nurse. They may be able to alter the treatment or prescribe a drug to help you feel better.

Mouth Care

It is important to take care of your mouth, teeth and gums during radiation.

1. Careful brushing of your teeth can help prevent tooth decay, gum disease, mouth sores and jaw infections.

2. Be sure to tell your dentist that you received radiation to the head and neck area.

3. Talk to your doctor or dentist about any problems you are having.

Follow-Up Testing

Thyroid cancer patients undergo periodic monitoring for the rest of their lives.

The type of testing and how often it takes place depend on the size of the tumor, whether there was spread, and other factors.

Patients who are free of disease receive less monitoring than those with evidence of disease.

The testing is spread out over time, at less frequent intervals, when the patient becomes free of disease.

However, even those patients cured of their thyroid cancer need to see a doctor at least once a year for measurement of thyroglobulin and thyroid function tests.

Testing may include:

Thyroid scan (radioactive iodine whole-body scan) either after thyroid hormone withdrawal or after administration of recombinant TSH (Thyrogen).

Neck Ultrasound. This test is increasingly used, because it is a very sensitive way to find disease in the neck.

Blood testing for TSH (thyroid stimulating hormone). Often, this is done about every 3 to 6 months during the first few years after diagnosis and less frequently later on.

The frequency of thyroid function testing (TSH testing) also depends on the age of the patient. Younger children typically require more frequent monitoring for longer periods of time.

Blood testing for Thyroglobulin (Tg).
- This is another important test, because thyroglobulin is made only by thyroid cells, normal and cancerous.
- Often, Tg measurements are done every time the TSH is checked, although, with more time from diagnosis and with no evidence of disease, the frequency of Tg monitoring becomes less frequent, usually only once a year.
- About one quarter of patients make an antibody against thyroglobulin (antithyroglobulin antibody) that prevents interpretation of the actual Tg level.
- In effect, the presence of thyroglobulin antibodies will usually cause the Tg level to read artificially low. In these cases, the antibodies levels themselves can be monitored and should become undetectable, in most patients with no evidence of disease, by 3-5 years after diagnosis.
- This website has an article with more information about Thyroglobulin measurement and the different tests used.

Physical Examination. Typically, this is done every 3 to 6 months for the first 2 years and then once a year if there is no recurrence of the thyroid cancer.

Other tests sometimes used:

- Chest X-Ray
- CT scan with or without contrast. The CT should be without contrast if the use of radioactive iodine is planned shortly thereafter. Otherwise, a 24-hour urine collection for iodine may be collected prior to any use of RAI to ensure that the iodine load from the CT contrast has been cleared.
- PET scans for those with persistent elevations of thyroglobulin and no evidence of disease on ultrasound, RAI scan, and other imaging methods.