Radiotherapy for thyroid cancer can cause side effects, which may happen during treatment, shortly after, or much later. Early side effects (also called acute) usually occur during or soon after treatment. Since everyone is different, it’s hard to predict exactly when side effects will start, how long they will last, or how severe they might be. If you’re worried about anything, it’s best to talk to your treatment team.
You may experience side effects or symptoms not listed here, as every person and treatment is different. These symptoms may also be caused by other parts of your cancer treatment. Research and support for managing radiotherapy side effects, including long-term effects, is improving.
Joining a support group can be a helpful way to share your experiences, feel less isolated, and cope with the physical and emotional effects of treatment. If you need extra support or experience any side effects, alert your treatment or clinical team straight away.
This page looks at early side effects.
How likely am I to get early side effects?
Before treatment you will discuss and sign a consent form with your clinical oncologist or therapeutic radiographer. They will tell you what to expect, and you can ask questions and discuss any concerns you have about late effects. It’s important to know what you are consenting to and can help to take someone with you.
You can read different radiotherapy consent forms (HERE) based on the specific area being treated. These consent forms are packed with useful information about early and late side effects.(1)
When you consent to treatment, you agree that you understand that you have a chance of getting late side effects. Your team will use words like, Expected, Common, Less Common and Rare.
This table shows what these words mean.
| Wording on the consent form | % chance of side or late effect | How many patients will get this? |
|---|---|---|
| Expected | 50 to 100% | Between half and all patients |
| Common | 10 to 50% | Up to half of all patients |
| Less common | Less than 10% | Fewer than one in ten patients |
| Rare | Less than 1% | Fewer than one in 100 patients |
Early side effects (during or soon after treatment)
- Feeling very tired or fatigued: You might feel very tired during and after your treatment. It’s important to get plenty of rest but sometimes you will still feel really tired, even with lots of sleep. Some tiredness can be caused by having cancer and having cancer treatment, and some can be caused by travelling to and from hospital every day for treatment.
- Skin reactions: You might notice a change in colour, swelling, itching, or changes in the texture of your skin where you’re treated. For people with lighter skin tones these changes can be pink, red or darker than the surrounding area. People with brown and black skin tones might have colour changes such as maroon, purple, yellow or grey pigment changes. Or the skin can look darker than the surrounding area. These changes usually improve after treatment, but this can take 4 to 6 weeks in some cases.
- Throat Problems: Radiotherapy can make your throat and food pipe (oesophagus) sore, making swallowing painful. You may also get heartburn-like symptoms. Your doctor can prescribe medicine to help.
- Mouth Problems: You might get a dry mouth, ulcers, thrush, and infections a few weeks into treatment, making it hard to eat. Don’t wait until the pain is severe—ask for medication, mouth washes and saliva substitutes to help and ease discomfort. A dietitian can help you maintain a good diet, some people find the taste of food changes. In some cases a feeding tube might be needed to help you get enough food and nutrition. In some cases you may be advised to have a feeding tube placed before starting radiotherapy. This can help you keep your weight up if you have trouble eating. If you lose a lot of weight, a new radiotherapy mask may be needed.
- Hair Loss: You might lose hair in the treated area, but it usually grows back over time.
- Voice Changes (Hoarseness): Your voice may become hoarse if the treatment irritates your voice box. Rest your voice and let your team know if it’s bothering you.
- Loss of appetite: This is common and becomes an issue if you cannot get enough food a nutrients to maintain your weight. You might experience feeling or being sick. Ask you team for support with this a dietician can help.
Less common and rare side effects
- Heart and Lung Inflammation: If the treatment area includes the lower neck and upper chest area, you may experience inflammation of the heart (pericarditis) or lungs (pleurisy), causing sharp pain, especially when breathing deeply. This inflammation is not dangerous and usually goes away on its own.
- Chest infections: Due to food going down the windpipe not food pipe.
- Swelling of the voice box: Making talking and swallowing more difficult.
- Dehydration: Due to not drinking enough.
- Lhermitte’s sign: Temporary changes to the spinal cord, feeling of sudden electric shock when bending the neck, may occur three to six months after treatment.
What can help with these early side effects?
- Resting: Make sure to get plenty of sleep and take breaks when you feel tired. Listen to your body.
- Drinking fluids: Drinking plenty of fluids such as water, juice and squash can help with fatigue and tiredness caused by your treatment. It can also help flush out toxins in your body caused by treatment. You can try diluted juice if you don’t like water.
- Skin Reactions: Your treatment team can recommend creams to soothe your skin. If your skin breaks down, you may need extra care. Wear loose clothing and avoid sun exposure. Talk to your team about how to wash and care for your skin during treatment.
- Get Help: It’s important to seek support from dietitians, physiotherapists, speech therapists, and other specialists early on. Managing symptoms like eating difficulties, swallowing issues, and stiffness is crucial for your long-term recovery.
- Stay in Touch: Always communicate with your treatment team about any side effects or concerns. They are there to help you feel better throughout your treatment.
- Keeping Active: Gentle movement can improve how you feel during and after treatment. Your treatment team can guide you on safe activities.
- Seek Support: Connecting with other patients and support groups can be beneficial as they understand what you’re going through.
- Alcohol use: Please follow the NHS guidelines on safe drinking levels and any instructions you get from your team on what is right for you, your diagnosis and your treatment. If in doubt, please ask your team.
- Stop smoking: If you are looking to stop or reduce smoking, there are services available to help you.
- Sexual changes: Talk to your team if you are experiencing issues with sex and cancer and they can offer advice.
