Having external radiotherapy for thyroid cancer

What is external radiotherapy?

Radiotherapy uses high energy waves similar to x-rays to destroy cancer cells. External radiotherapy uses a radiotherapy machine to aim radiation beams at a cancer. This is different to internal radiotherapy where you have radiotherapy from inside the body.

When you have external radiotherapy

You might have external radiotherapy if other treatments do not work very well. You may have it if:

• you still have signs of thyroid cancer after surgery

• your doctor doesn’t think radioactive iodine will control your cancer

• to treat thyroid cancer that's spread to another part of the body (secondary thyroid cancer)

• as a first treatment for anaplastic thyroid cancer that can't be removed with surgery

Radiotherapy is not routinely used to treat medullary thyroid cancer. But you may have it to control symptoms if the cancer cannot be completely removed. Or to treat an area of cancer spread.

How you have external radiotherapy

You have radiotherapy as a course of treatment. You usually go to the hospital for treatment once a day, from Monday to Friday, with a break at weekends for 4 to 6 weeks. 

You might have a shorter course of treatment or a single treatment if you are having radiotherapy to control symptoms.

Before your start radiotherapy you have a planning appointment. This is to work out the dose of radiotherapy you need and exactly where you need it.

Go to information about planning external radiotherapy

The radiotherapy room

Radiotherapy machines are very big and could make you feel nervous when you see them for the first time. The machine might be fixed in one position. Or it might rotate around your body to give treatment from different directions. The machine doesn't touch you at any point.

Before your first treatment, your ​radiographers​ will explain what you will see and hear. In some departments, the treatment rooms have docks for you to plug in music players. So you can listen to your own music while you have treatment.

Before each treatment session

The radiographers help you to get onto the treatment couch. You might need to raise your arms over your head.

The radiographers line up the radiotherapy machine using the marks on your body. Once you are in the right position, they leave the room.

During the treatment

You need to lie very still. Your radiographers might take images (x-rays or scans) before your treatment. This is to make sure that you're in the right position. The machine makes whirring and beeping sounds. You won’t feel anything when you have the treatment.

Your radiographers can see and hear you on a CCTV screen in the next room. They can talk to you over an intercom and might ask you to hold your breath or take shallow breaths at times. You can also talk to them through the intercom or raise your hand if you need to stop or if you're uncomfortable.

You won't be radioactive

This type of radiotherapy won't make you radioactive. It's safe to be around other people, including pregnant women and children.

Travelling to radiotherapy appointments

You might have to travel a long way each day for your radiotherapy. This depends on where your nearest cancer centre is. This can make you very tired, especially if you have side effects from the treatment.

You can ask your radiographers for an appointment time to suit you. They will do their best, but some departments might be very busy. Some radiotherapy departments are open from 7 am till 9 pm.

Car parking can be difficult at hospitals. Ask the radiotherapy staff if you are able to get free parking or discounted parking. They may be able to give you tips on free places to park nearby.

Hospital transport may be available if you have no other way to get to the hospital. But it might not always be at convenient times. It is usually for people who struggle to use public transport. Or who have any other illnesses or disabilities. You might need to arrange hospital transport yourself.

Some people are able to claim back a refund for healthcare travel costs. This is based on the type of appointment and whether you claim certain benefits. Ask the radiotherapy staff for more information about this and hospital transport.

Some hospitals have their own drivers and local charities might offer hospital transport. So do ask if any help is available in your area.

Side effects

Modern radiotherapy techniques mean that your team can target a very precise area containing the cancer. They also try to plan your treatment so that it causes as few side effects as possible.  But any healthy cells in the treatment field are also affected and this causes side effects.

Radiotherapy to the neck can cause:

• tiredness (fatigue)

• sore, red skin in the treatment area

• a sore mouth or throat (mucositis)

• difficulty swallowing (dysphagia)

• a dry mouth

• a hoarse voice

• swelling in your face or neck (lymphoedema)

Radiotherapy side effects usually start gradually, during your course of treatment. Not everyone has side effects. But if you are going to get them, they are usually at their worst around 10 to 14 days after the end of your course. Over the following 2 to 3 weeks, they slowly get better.

If you have side effects, speak to the radiographer or nurse in your radiotherapy department. They will be able to help you. If your throat is very sore, you may need painkillers.

Generally, doctors prefer to give the radiotherapy without any breaks. But very rarely, where side effects are particularly severe, treatment can be stopped for a while to allow you to recover.

Remember not to put any lotions, powders or creams on skin in the treatment area without checking with your nurses, radiographers or doctors. If you have any soreness, these may make things worse not better. Ask at the radiotherapy department and the staff can give you something to soothe your skin if you need it.

It would also be best to avoid shaving your face, as it will irritate your skin more.

You can find more information about the side effects of radiotherapy to the head and neck area and other parts of the body.

Go to our general side effects of radiotherapy section