Thyroid Cancer
The thyroid is made up of two lobes that wrap around the windpipe in the lower neck.
The thyroid makes a hormone which controls how our bodies turn food into energy. This is called metabolism.
When people get thyroid cancer, it doesn’t usually change their metabolism. Instead, most people get a painless lump in the front of the lower neck.
Thyroid cancers tend to grow slowly. They don’t usually cause problems with breathing or swallowing until they are quite large.
Many people have small lumps in their thyroid and most of these are not cancer. Doctors do an ultrasound on the thyroid and neck to check the lumps. If the lumps look suspicious the doctor will then do a biopsy to check for cancer.
Thyroid cancer is uncommon, but numbers are growing. People of any age can get thyroid cancer and it is more common in women.
*Thyroid Eye disease is different to thyroid cancer. Learn about thyroid eye disease here.
Radiation Therapy and Thyroid Cancer
The best person to talk to about radiation therapy for thyroid cancer is a radiation oncologist. A radiation oncologist is a specialist doctor who is part of the team that takes care of people having radiation therapy.
You can ask your doctor for a referral to a radiation oncologist to learn if radiation therapy is an option for you.
The Treatment Team
Doctors make a treatment plan for each person based on:
- the type of cancer
- where the cancer is
- what other treatments have been tried
- the person’s health.
The type of treatment a person gets is worked out by a team of doctors and health professionals often called a Multidisciplinary Team.
A highly trained radiation oncology team takes care of people having radiation therapy. This includes radiation oncologists, radiation therapists, medical physicists and radiation oncology nurses.
Treatments for Thyroid Cancer
For small thyroid cancers doctors can operate and remove one lobe of the thyroid.
If the cancer is large or has spread to the lymph nodes, doctors may remove the whole thyroid and use a radiation therapy as well.
People who have their whole thyroid taken out must have replacement thyroid hormone tablets. People take these tablets once a day and they supply the same hormone as the thyroid gland.
Doctors don’t usually use chemotherapy for thyroid cancer. However, new drugs called Tyrosine Kinase inhibitors can be used for people with more advanced cancer.
Types of Radiation Therapy Used for Thyroid Cancer
Radioactive Iodine (RAI)
People swallow RAI as a capsule. RAI targets thyroid cancer very well. Apart from a little in the salivary glands, people do not get RAI in other body parts.
RAI gives a very high dose of radiation to the cancer without hurting other cells. RAI does not affect fertility, which is very important for young women who may want to have children later in life.
People stay in hospital for 2-3 days during RAI treatment.
People stay in hospital for 2-3 days during RAI treatment.
External Beam Radiation Therapy (EBRT)
For some, mostly older, people the tumour may not take up enough RAI to work. In this case, radiation oncologists can use External Beam Radiation Therapy (EBRT) to treat the tumour.
External Beam Radiation Therapy (EBRT) is also used to treat other cancers in the Head and Neck.
For thyroid cancer, radiation oncologists often use an advanced type of external beam radiation therapy called Volumetric Arc Therapy (VMAT) to carefully deliver radiation to treatment areas.
This technique allows the radiation oncologist to target the radiation on the cancer while limiting radiation to healthy parts of the body.
People usually get radiation therapy for thyroid cancer daily from Monday-Friday for a few weeks.
The treatment team works out the right number of treatments for each person.
For people with advanced thyroid cancer or cancer has spread radiation oncologists may offer palliative radiation therapy using external beam radiotherapy. This can help with pain and other symptoms.
General Information About Side Effects of Radiation Therapy
Radiation therapy is more effective with fewer side effects than ever before.
Recent advances mean radiation oncologists can effectively treat the cancer while getting less radiation on healthy body parts. This means much fewer side effects.
Side effects from radiation therapy vary between people, even for those having the same treatment.
While some people feel no side effects, some feel mild side effects, such as tiredness or skin redness during and/or just after treatment. These usually get better within a few weeks.
The treatment team will offer advice and medicine to help with side effects.
Serious side effects that start later (months to years after the radiation therapy) are rare.
Before starting treatment, your radiation oncologist will talk to you about side effects and answer your questions.
The side effects of radiation treatment can be split into 2 groups:
- Early side effects which occur during and shortly after radiation treatment.
- Late side effects which can occur months to years after radiation treatment.
For more information, go to the Potential Side Effects page.
Early Side Effects of Radiation Therapy for Thyroid Cancer
Early side effects: occur during and shortly after radiation treatment. Common early side effects of radiation therapy include:
Fatigue: This is very common in the second half of treatment and varies between people. Tiredness may continue for several weeks after treatment.
Dry mouth: RAI can cause a dry mouth, usually only after many doses. Sipping water or using artificial saliva helps. Some people also get thick saliva. Salt water mouth washes and breathing humidified air can help. Mouth dryness usually gets better over time but may not get right back to normal.
Soreness in the mouth/throat: This often happens early in treatment and can cause pain swallowing. This makes it hard to eat and drink. Doctors offer advice and medicine to help and this often gets better 4-8 weeks after treatment.
Different taste and/or loss of appetite: Some people lose their taste or say food tastes different. For example, sweet foods may taste salty or metallic. This can make people less hungry. This usually gets better in time, though some people have a long-term change.
Skin changes: Some people get red, itchy skin. This usually gets better 4-6 weeks after treatment. Doctors can offer advice and medicine that helps.
Hair loss: Some people lose their hair in the area treated. How much hair grows back depends on the radiation dose to the skin. If the skin is in or near a high dose area, the hair loss will last. Hair loss due to low dose radiation generally grows back.
Ear ache or blocked sensation: This can occur due to swelling of the tube that connects the middle ear to the back of the nose.
Hoarse voice: Some people notice a change in voice if there is swelling and irritation of the voice box due to treatment.
Breathing difficulty: If a person’s airway is inflamed and swollen from treatment this can cause breathing problems. In rare cases, this swelling is bad and causes noisy breathing which should be seen by the doctor.
Late Side Effects of Radiation Therapy for Thyroid Cancer
Late side effects vary between people and can happen a few months to a few years after treatment.
These side effects may never occur, occur once, continue over time, or come and go.
Dry mouth: For some people a dry mouth carries on in the long term. If this happens it helps to drink lots of water and use artificial saliva.
Teeth and jaw issues: Teeth are more at risk of tooth decay after treatment. It helps to keep your mouth and teeth clean and visit the dentist. Be sure to tell your dentist if you have radiation therapy.
Neck stiffness: Sometimes the soft tissues of the neck become hard and stiff. This may mean your neck doesn’t move as well. In most cases this is mild, but in some cases the stiffness can be bad. A physio can help.
Neck swelling: Some people notice a swelling in their neck, often under the chin. This is due to poor flow of lymph fluid. A physio or occupational therapist who specialises in this can help. This is a cosmetic problem that usually gets better in time.
Troubles with swallowing: Some people have problems swallowing after treatment. Doctors provide ideas to help with this. A feeding tube may be needed if someone has troubles eating.
Hair loss: Permanent hair loss can occur in the area that has been treated.
Skin changes: Thinning and dryness of skin and changes in skin tone can happen after treatment. Blood vessels may be more noticeable.
Change in voice: Hoarseness of voice usually gets better after treatment but sometimes it lasts for several months. Rarely, there is a lasting change in voice, especially if the voice box is treated.
Underactive thyroid gland: This can make people feel tired and can usually be fixed with medicine.
Soft tissue damage: This is rare and causes non-healing sores.
Damage to the jaw: This is rare but it can happen after post treatment dental surgery due to less ability to heal and an increased chance of infections.
Breathing difficulty: This is rare and due to swelling of the airway.
Narrowing of the arteries: There may be an increased risk of stroke if the arteries to the brain are shrunk by radiation therapy. People can try and control blood pressure, do regular exercise and stop smoking to reduce the risk of this.
Nerve/spinal cord injury: Irritation of the spinal cord causing an electric-like feeling can occur several months after treatment. This usually doesn’t need treatment and gets better in time. Long-term effects are very unlikely.
Cataract: This is very rare.
Second cancer: Cancers caused by radiation therapy are a very rare side effect.
Other Useful Resources for Thyroid Cancer
Find additional information about cancer types, research groups, and support groups.
Radiation Oncologist
The best person to talk to is a radiation oncologist. You can ask your doctor for a referral to find out if radiation treatment is right for you.
GPs and Health Professionals
Information for any health professional involved in a patient's cancer care with a particular focus on primary care providers.
Talking to Your Doctor
Your GP or other doctors in the cancer team can organise a referral to a radiation oncologist.
Treatment Centres
Search and find your closest Radiation Oncology Treatment Centre.
