Radiation Therapy for Nasal Cavity and Paranasal Sinus Cancers

Radiation therapy uses high-energy radiation to kill cancer cells. It may be used in several ways for nasal and paranasal sinus cancers:

• As the main (primary) treatment. People with small nasal cavity tumors can often be cured with radiation alone with less change in their facial appearance than if they had surgery. People whose general health is too poor for surgery may also receive radiation therapy as their only treatment.
• After surgery to try to kill any small areas of cancer that were not seen but may remain. This is called adjuvant treatment.
• Before surgery to try to shrink the tumor so it is easier to remove. This is called neoadjuvant treatment.
• To help with symptoms like pain, bleeding, and trouble swallowing. This is known as palliative treatment.
• When the cancer has spread to the brain or spinal cord.

There are 2 major types of radiation therapy: external beam radiation therapy and 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 known as external beam radiation.

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 procedure itself is painless. Each treatment lasts only a few minutes, although the setup time – getting you into place for treatment – usually takes longer.

External beam radiation therapy usually means having treatments 5 days a week for about 6 to 7 weeks. Other schedules for radiation doses have been studied in clinical trials.

Hyperfractionation refers to giving the total radiation dose in a larger number of doses (2 smaller doses per day instead of 1 larger dose, for example). Accelerated fractionation means that the radiation treatment is completed faster (6 weeks instead of 7 weeks, for instance).

Several newer techniques help doctors focus the radiation more precisely, and may be helpful in some situations.

Three-dimensional conformal radiation therapy (3D-CRT): 3D-CRT uses the results of imaging tests such as MRI and special computers to map the location of the tumor precisely. 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 normal tissues, but the beams converge at the tumor to give a higher dose of radiation there. Patients are fitted with a mold or cast to keep the body part still so the radiation can be aimed more accurately.

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. In addition to shaping the beams and aiming them at the tumor from several angles, the intensity (strength) of the beams can be adjusted to minimize the dose reaching the most sensitive nearby normal tissues. This may let the doctor deliver a higher dose to the tumor. Many major hospitals and cancer centers now use IMRT as the standard way to deliver external beam radiation.

Stereotactic radiosurgery (SRS): SRS is not really surgery, but a type of radiation treatment that gives a large dose of radiation to a small tumor area in one session. It is mostly used for brain tumors and other tumors inside the head. In some cases, a head frame or shell may be used to help keep the patient’s head still and aim the radiation beams precisely. Once the exact location of the tumor is known from the CT or MRI scans, radiation is sent to the area from a machine. The radiation is very precise and nearby tissues are affected as little as possible. Most of the time, stereotactic radiosurgery treatment gives the whole radiation dose in one session. The main advantage of SRS over IMRT is the shortened treatment time.

Brachytherapy

Another way to deliver radiation is to insert (implant) very thin metal rods containing radioactive materials in 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. This is sometimes done if the cancer comes back after external beam radiation therapy.

The implant is usually left in place for several days while the patient stays in a private hospital room. The length of time that visitors, nurses, and other caregivers can spend with the patient may be limited because of potential radiation exposure, but this depends on the type of radiation. The implants are removed before the patient goes home. Sometimes, internal and external beam radiation therapy are used together. With more modern approaches to delivering radiation such as IMRT and SRS, brachytherapy is less commonly performed.

Side effects of radiation therapy

Common side effects include:

• Skin problems (like a sunburn)
• Nausea
• Loss of appetite
• Feeling tired or weak
• Mouth/throat pain and sores in the mouth (called mucositis)
• Trouble swallowing
• Hearing loss
• Hoarseness
• Problems with taste
• Bone pain
• Bone damage

Problems with mucositis can be severe enough that patients have trouble eating and drinking. This can lead to weight loss and malnutrition. Some people need to rely on tube feedings during treatment to keep up their strength. With tube feedings, a liquid food is given through a tube that is placed directly into the stomach through a small hole in the belly.

Most of these symptoms will go away shortly 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, vision could be damaged.

Radiation therapy to the head or neck area often damages the salivary (spit) glands, making the mouth very dry. This can lead to problems eating and swallowing. This is a very common side effect of radiation to the head and neck areas, and is often permanent. This side effect can be lessened if a drug called amifostine (Ethyol^®) is given before each radiation treatment. There are also fewer problems with dry mouth if IMRT is used.

Along with discomfort and problems swallowing, a dry mouth can lead to tooth decay. Radiation can worsen any tooth problems that already exist. You may be advised to see a dentist to check your teeth before treatment. Depending on the expected radiation plan and the condition of your teeth, some of your teeth may need to be removed before starting treatment. People with dry mouth after radiation must pay close attention to their oral health.

If the pituitary or thyroid glands are exposed to radiation, their production of hormones may decrease over time. This can lead to problems with metabolism that may need to be corrected with medicine.

Sometimes chemotherapy is given with radiation to help it work better. This is called chemoradiation, and it has more severe side effects than when radiation is given by itself. However, there are ways to relieve many of the side effects caused by radiation, so it’s important to discuss any symptoms with your cancer care team.

For more information on radiation therapy, see the Radiation Therapy section of our website, or our document A Guide to Radiation Therapy.