Side effects of nasal and paranasal sinus cancer radiotherapy

Your mouth and throat are likely to become increasingly sore. The lining may break down (get ulcerated) as you go through your treatment. This might be worse if you're having radiotherapy with chemotherapy (chemoradiotherapy). 

You might need strong painkillers such as morphine.

Your doctor might also prescribe a gel. It forms a protective coating over the inside of your mouth, a bit like a dressing. This can make your mouth less painful and can make it easier to eat and drink.

Mouth care is important for this type of treatment. Your nurse or radiographer will give you mouthwashes and will tell you on how to use them. Try to do this as often. The temptation is to leave it if your mouth is sore. But it is important to use them to prevent infection.

At the first sign of infection (particularly high temperature with chills, a sore chest or cough), contact the hospital. You may need antibiotics through a drip. 

It is important that you do this without delay if you are also receiving chemotherapy. Your immune system may be weakened, and you will not be able to fight an infection in the normal way. Most hospitals give you an emergency card. This will help you to know exactly what to do if you develop a temperature whilst receiving chemotherapy.

Radiotherapy to this area can cause damage to the glands that produce your spit. They are also called salivary glands. This can come on within a couple of weeks of starting your treatment.

Some people say they are making saliva, but it is thicker and stickier. This can make it harder to chew and swallow.

After the treatment, you may have a temporary dry mouth for a while, but for some people this may be permanent. It can make eating and talking very uncomfortable. 

If you have trouble with a dry mouth, your doctor can prescribe artificial saliva to keep it moist. This will make you more comfortable.

You are more likely to get an infection or tooth decay if your mouth is dry. So you’ll need to keep an eye on this and have regular check ups with your dentist.

There is some evidence to suggest that having acupuncture may help with a dry mouth.

You may lose your sense of taste, have strange tastes or dulled taste. People often describe a metallic taste in their mouth with radiotherapy. Some chemotherapy drugs may cause similar changes in your taste. 

Loss of taste will affect your appetite. This doesn’t help when you are finding it difficult to eat anyway. Although you can recover your sense of taste, some people may find it is permanently dulled.

Your eyes are close to the nose and paranasal sinuses. Having radiotherapy to this area sometimes means that your eye is in the path of the treatment.

If it is, the radiotherapy may damage some parts of your eye and change how well you can see. 

Your doctor will discuss with you in detail how treatment may affect your eye and sight.

Radiotherapy can damage the cells in your nose that give you your sense of smell. This may be while you have your treatment and during your recovery. 

Some people may find their sense of smell never quite gets back to normal.

Radiotherapy to the nasal cavity or paranasal sinuses can affect your hearing. You may find it hard to hear soft sounds. Or you may have problems to tell different sounds apart. 

This may only be a temporary problem while you have your treatment and are recovering from it. In some people hearing loss can be permanent. A hearing aid may be recommended as well as regular checks for wax build up in your ear canal.

Radiotherapy to the neck can damage the thyroid gland. If this happens, you will need to take pills to replace thyroid hormones.

You will have thyroid tests after your course of radiotherapy.

Radiotherapy can damage the nerve controlling the muscles which move your mouth. This can make it difficult for you to open it.

This is called trismus. If it happens, your doctor or nurse will give you exercises to do to help relieve the problem.