Radiation Therapy for Nasopharyngeal Cancer

Most nasopharyngeal cancers are sensitive to radiation, so it is usually part of the initial treatment if the cancer hasn’t spread outside the head and neck region. Radiation therapy uses high-energy x-rays or particles to kill cancer cells or slow their rate of growth.

Intraoperative radiation therapy (IORT)

In rare cases, intraoperative radiation therapy (IORT) may be used to treat nasopharyngeal cancer, usually at large hospitals with special experience.

IORT is given during surgery, after the doctor removes as much of the tumor as possible. A strong, focused dose of radiation is then delivered directly to the area where the cancer was removed. This treatment may be followed by regular external radiation to help kill any remaining cancer cells.

Doctors carefully choose who can receive this treatment. It works best for people who are in good overall health, had radiation more than 2 years ago, had surgery to remove most of the cancer first, and do not have major organ problems, such as needing a feeding tube or having serious breathing or swallowing issues.

Because this treatment is complex, it is only used in special cases and for carefully selected patients.

Brachytherapy

Brachytherapy is another way to deliver radiation. You might also hear this called internal radiation. Very thin metal rods or wires, which carry small pellets of radioactive materials, are placed in or very near the cancer. The radiation travels a very short distance, so it destroys the cancer without causing much harm to nearby healthy tissues.

Brachytherapy is not often used as a first treatment for nasopharyngeal cancer. It might be used if the cancer comes back or does not go away completely with chemoradiation. Sometimes, internal and external beam radiation therapy are used together.

Seeing a dentist before radiation treatment

Radiation to this part of your body can cause problems for your teeth and gums. Before you start treatment, it's important to see a dentist to make sure your mouth is healthy.

The dentist might recommend removing certain bad teeth before you start radiation because they can increase your chance of infection. The dentist will probably also recommend using some form of fluoride treatment after completing radiation.

During and after treatment, your dentist can help check for and address any problems that might come up, such as infection or tooth and bone damage.

Possible side effects of radiation therapy for NPC

Before you begin radiation therapy, it’s important to ask your cancer care team about the possible side effects so you know what to expect.

Common short-term side effects

Common short-term side effects of external beam radiation to the head and neck can include:

• Skin changes in the area where the radiation is directed, with redness or blistering
• Nausea and vomiting
• Fatigue (extreme tiredness)
• Sores in the mouth and throat, which can lead to trouble swallowing and weight loss from not eating
• Hoarseness
• Loss of taste

These side effects often get better once radiation is complete.

Long-lasting or permanent side effects

Some side effects might not get better over time, such as:

• Damage to the bones of the skull
• Problems with hearing or vision because of damage to certain nerves

Tooth problems. Radiation to these areas can make any existing tooth problems worse and hard to fix. Most doctors suggest a dental exam before starting radiation therapy to the head or neck area. In some cases, the dentist may advise removing some teeth before treatment to lessen the chance that you'll have problems later, such as an infection.

Dry mouth. This is a major concern with radiation therapy for NPC. Damage to the salivary glands can cause dry mouth that doesn't go away. This can make it hard to swallow food and also lead to severe tooth decay. To help prevent dental problems, people treated with radiation to the head or neck area need to practice careful oral hygiene and see the dentist regularly. Dry mouth is less of a problem if IMRT is used.

Thyroid problems. The thyroid gland is often damaged if the neck area is treated with EBRT. This damage doesn’t cause problems that are noticed right away, so your health care team will watch your thyroid function with blood tests in the years after treatment. If your thyroid function goes down, you may need pills to replace your thyroid hormone.

Lymphedema. Some people treated with radiation therapy might be at risk of developing lymphedema in the head and neck areas that were treated. These areas can become swollen and firm. This can be worse if you also had surgery. Medicines, physical therapy, or massage therapy might sometimes be helpful.

Damage to the pituitary gland. Your pituitary gland controls many hormones in your body. Doctors can use blood tests to look for abnormal hormone levels if your pituitary is damaged by radiation treatment. If the damage is serious enough, you might need to take certain hormones to replace the ones that are missing.

Damage to the carotid arteries. These are major blood vessels in your neck that carry blood to your brain. They can sometimes become narrowed after radiation. This could raise the risk of stroke or other problems, but it usually takes several years to occur.