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Radiation therapy for nasal cavity and paranasal sinus cancer
Radiation therapy uses high-energy rays or particles to destroy cancer cells. Most people with cancer in the nasal cavity or paranasal sinuses have radiation therapy. Your healthcare team will consider your personal needs to plan the type and amount of radiation, and when and how it is given. You will likely receive other treatments.
Radiation therapy may be given alone. It may also be given during the same time period as chemotherapy (called chemoradiation) or along with targeted therapy.
Radiation therapy is given for different reasons. You may have radiation therapy to:
- destroy the cancer cells in the body
- destroy cancer cells left behind after surgery and reduce the risk of the cancer recurring (called adjuvant therapy)
- shrink a tumour before other treatments such as surgery or chemotherapy (called neoadjuvant therapy)
- relieve pain or control the symptoms of advanced cancer (called palliative therapy)
- destroy cancer cells that may have spread to the lymph nodes in the neck
Before radiation therapy
Talk to your healthcare team to find out what you need to do before radiation therapy begins. They may discuss the following, depending on your personal needs.
Smoking during treatment may make radiation therapy less effective. Smokers may also have worse side effects from radiation therapy.
If you smoke, try to quit smoking before you start radiation therapy.
Visiting your dentist
Most people have a thorough dental exam before radiation therapy begins to prevent dental problems. The dentist will determine if you need to have any dental work, such as having unhealthy teeth removed. Your dentist will also develop a dental care plan for you to follow after radiation therapy.
Getting fitted for an immobilization mask
Many people have a custom immobilization mask made before treatment with external beam radiation therapy. An immobilization mask is often used when radiation therapy is given to the head and neck. The mask makes sure that you don’t move during treatment and that radiation is directed at exactly the same place each time. You need to wear it during treatment planning and all radiation treatments.
Making sure your nutritional needs are met
A gastrostomy is surgery to make an opening directly into the stomach. A feeding tube is passed into the stomach through the gastrostomy opening. When food and liquids are given directly into the stomach, it is called enteral feeding. A gastrostomy tube can help you meet your nutritional needs when you find it too difficult to eat or drink.
Radiation therapy to the head and neck can make swallowing difficult and painful. The healthcare team may place a gastrostomy tube before radiation therapy starts to make sure you will get the nutrition you need.
Find out more about tube feeding.
Types of radiation therapy
The following are the types of radiation therapy most commonly used to treat cancer in the nasal cavity or paranasal sinuses.
External beam radiation therapy
Nasal cavity and paranasal sinus cancer is often treated with external beam radiation therapy. Small tumours in the nasal cavity can be treated successfully by radiation therapy alone. It is often done instead of surgery because radiation therapy causes fewer changes to the look of the face.
During external beam radiation therapy, a machine directs radiation through the skin to the tumour and some of the tissue around it. You may also have radiation to the neck if your doctor thinks that the cancer may have spread to the lymph nodes in the neck (called cervical lymph nodes).
External beam radiation therapy is usually given once each day for 5–7 weeks. If it is given after surgery, radiation therapy usually starts 4–6 weeks after you have surgery. The healthcare team will take care to protect healthy tissue in the area from radiation as much as possible. These tissues include the eyes, brain stem, tongue, spinal cord, salivary glands, thyroid and pituitary gland.
The following are newer ways of giving external beam radiation therapy. They may be used to treat nasal cavity and paranasal sinus cancer.
Conformal radiation therapy
Conformal radiation uses a special device that can change the shape of a radiation beam so it better fits, or conforms to, the shape and size of the tumour. This helps to better target the tumour and spare more of the nearby structures than conventional radiation therapy. This means that more radiation is directed at the tumour and there is less radiation damage to normal tissues around the tumour.
The following types of conformal radiation therapy may be used to reduce damage to tissues near the nasal cavity and paranasal sinuses, such as the brain, eye, optic nerve, spinal cord and parotid glands.
3-dimensional conformal radiation therapy (3-D CRT) delivers radiation to the tumour from different directions. The radiation beams are all the same strength.
Intensity-modulated radiation therapy (IMRT) uses computer-generated images and radiation beams of different strengths to deliver higher doses of radiation directly to a tumour. It may be a treatment option for large tumours in the nasal cavity or paranasal sinuses and tumours that have grown into the base of the skull. IMRT uses specialized equipment so it might not be available at all cancer treatment centres in Canada.
Hyperfractionation and accelerated fractionation schedules
External beam radiation therapy is usually given once a day for 5–7 weeks. Research shows that some people with nasal cavity and paranasal sinus cancer may benefit from smaller doses of radiation given more frequently (called hyperfractionation) or giving the same total dose in a shorter amount of time (called accelerated fractionation).
Hyperfractionation divides the total dose of radiation into smaller doses that are given more frequently. Radiation treatments may be given 2 or more times a day (instead of once a day). This allows the person to receive many, smaller doses of radiation for a higher overall dose, which may cause more damage to the cancer cells. The treatments are usually given about 4–6 hours apart to allow normal tissues to heal. Radiation therapy using hyperfractionation is sometimes used to treat recurrent cancer in the nasal cavity or paranasal sinuses that was previously treated with radiation therapy.
Accelerated fractionation means giving radiation therapy over less time, or accelerated. This allows the person to finish the radiation treatments more quickly (for example, in 5 instead of 7 weeks). The number of fractions, total dose and size of each dose per fraction can vary, depending on the overall length of treatment.
Hyperfractionation and accelerated fractionation can cause more severe short-term side effects than standard external beam radiation therapy.
Stereotactic radiosurgery directs radiation beams to a very specific area to deliver a single high dose of radiation (called a single fraction). It doesn’t involve surgery. A surgical cut, or incision, is not made and tissue is not removed. The main advantage of stereotactic radiosurgery is that the treatment time is shorter than IMRT. Stereotactic radiosurgery isn’t often used to treat nasal cavity and paranasal sinus cancer. Stereotactic radiosurgery isn’t available in all treatment centres in Canada.
Brachytherapy is internal radiation therapy. It uses a radioactive material called a radioactive isotope. It is placed right into, or very close to, the tumour. Radioactive materials can also be placed in the area from where the tumour was removed. The radiation kills the cancer cells over time.
Brachytherapy may be used, with or without external beam radiation therapy, to treat early-stage tumours in the nasal cavity or the nasal vestibule. Interstitial brachytherapy is usually given for these tumours. It uses implants, which are thin needles containing a radioactive substance, placed directly into the tumour and surrounding tissue.
Brachytherapy may be given in low-dose or high-dose rates.
Find out more about brachytherapy.
Low-dose-rate (LDR) brachytherapy delivers continuous, low doses of radiation over time (usually 5–7 days for nasal cavity and paranasal sinus cancer). People who have this treatment usually need to stay in the hospital. Special safety precautions are taken to make sure other people aren’t exposed to radiation.
High-dose-rate (HDR) brachytherapy delivers a single, high dose of radiation in a very short period of time. A single treatment usually takes a few minutes. Iridium is the most common radioactive substance used for HDR brachytherapy for cancer in the nasal cavity or nasal vestibule. HDR brachytherapy is usually given after external beam radiation therapy during the last week of treatment (usually week 6).