Radiation Therapy for Nasal Cavity and Paranasal Sinus Cancers

Radiation therapy uses high-energy radiation to kill cancer cells. It's used in many ways to treat nasal and paranasal sinus cancers:

• It may be the main (primary) treatment. People with small nasal cavity tumors can often be cured with radiation alone. And it doesn't change the way they look as much as surgery does.
• People who can't have surgery due to poor health or because the tumor is too advanced to remove may get radiation therapy as their only treatment.
• After surgery, radiation can be used to try to kill any small areas of cancer that may remain. This is called adjuvant treatment. This the most common treatment for these tumors -- surgery then radiation.
• Radiation might be given before surgery to try to shrink the tumor so it's easier to remove. (It may be given along with chemo.) This is called neoadjuvant treatment.
• It can help ease problems caused by the cancer, like pain, bleeding, and trouble swallowing. This is called palliative treatment.
• Elective radiation may be used to treat lymph nodes in the neck even if they don't appear to have cancer cells in them. But not all doctors agree on this.

Sometimes chemotherapy is given along with the radiation. This is called chemoradiation. It can work better than radiation alone, but it also has more side effects. (See Chemotherapy for Nasal Cavity and Paranasal Sinus Cancer for more details.)

Before starting radiation treatments you will be advised to see a dentist. Radiation to this part of your body can affect your teeth and gums. A dentist can make sure your mouth is healthy before treatment. During and after treatment a dentist can help check for and treat any problems that may come up, such as infection or tooth/bone damage.

There are 2 major types of radiation therapy: external beam radiation therapy and internal radiation (called brachytherapy).

External beam radiation therapy

The most common way to deliver radiation to a paranasal or nasal tumor is to focus a beam of radiation from a machine outside of the body. This is called external beam radiation.

These tumors are close to many important organs and tissues, like the eyes, brain, glands, nerves, and blood vessels. Before your treatments start, the radiation team will take careful measurements to determine the correct angles for aiming the radiation beams and the proper dose of radiation. Radiation therapy is much like getting an x-ray, but the radiation is stronger. The machine doesn't touch you and treatment doesn't hurt. 

Each treatment lasts only a few minutes, but the setup time – getting you into place for treatment – usually takes longer. Patients are fitted with a mold or cast to keep the head, neck, and shoulders still and in the exact same position so the radiation can be aimed more accurately each time. You might also be fitted for a bite block that you hold in your mouth during treatment.

In most cases, external beam radiation therapy means treatments are given 5 days a week for about 6 to 7 weeks. Other schedules for radiation may be used, too.

Hyperfractionation refers to spreading out the total radiation dose into more doses, for instance, 2 smaller doses each day instead of 1 larger dose. Accelerated fractionation means that the radiation treatment is completed faster (6 weeks instead of 7 weeks, for instance).

These special techniques help doctors focus the radiation more precisely:

Three-dimensional conformal radiation therapy (3D-CRT): 3D-CRT uses the results of imaging tests such as MRI and special computers to map the exact location of the tumor. Several radiation beams are then shaped and aimed at the tumor from different directions. Each beam alone is fairly weak, which makes it less likely to damage the normal tissues it passes through. But the beams all meet at the tumor to give a high dose of radiation there.

Intensity modulated radiation therapy (IMRT): IMRT is an advanced form of 3D therapy. It uses a computer-driven machine that actually moves around the patient as it delivers radiation. Along with shaping the beams and aiming them at the tumor from several angles, the intensity (strength) of the beams can be adjusted to limit the dose reaching the nearby normal tissues. This may let the doctor deliver a higher dose to the tumor with fewer side effects. IMRT is the standard way to deliver external beam radiation for these cancers.

Brachytherapy

Another way to deliver radiation is to put radioactive materials right into or near the cancer. The radiation travels only a very short distance, which limits its effects on nearby normal tissues. This method is called internal radiation, interstitial radiation, or brachytherapy. Internal and external beam radiation therapy may be used together to treat nasal cavity and paranasal sinus cancers, but this is rare. More research is needed to know if it helps and how to best use it.

Side effects of radiation therapy

Many people treated with radiation to the neck and throat area get painful sores in the mouth and throat that can make eating and drinking very hard. This can lead to weight loss and malnutrition. Some people need tube feedings during treatment to keep up their strength. (With tube feedings, a liquid food is given through a tube that's put right into the stomach through a small hole in the belly.) The sores heal with time after the radiation has stopped, but some people continue to have problems swallowing long after treatment ends.  Ask about swallowing exercises you can do to help keep those muscles working and increase your chance of eating normally after treatment.

Common side effects include:

• Skin problems in the area being treated, ranging from redness to blistering and peeling
• Nausea
• Loss of appetite
• Feeling tired or weak
• Trouble swallowing
• Hearing loss
• Dry eyes
• Hoarseness
• Problems with taste
• Bone pain
• Bone damage
• Brain damage (this is quite rare)

Side effects of radiation tend to be worse if chemotherapy is given at the same time.

Tell your doctor about any side effects you have because there are often ways to help. Most of these problems will go away over time after the radiation is finished, but some side effects can be permanent. For example, if an eye is in the path of the radiation beam, it could change the way you see through that eye.

Radiation aimed at the head and neck might damage the salivary glands, leading to dry mouth that doesn't get better with time. This can cause discomfort and problems swallowing. It can also lead to tooth decay. People treated with radiation to the neck and throat must pay close attention to their oral health.

If the pituitary or thyroid glands are exposed to radiation, they may be damaged. Your doctor will do blood tests to see how well these glands are working. You may need to take thyroid medicine if there are problems.