Radiotherapy side-effects

It‘s very common to feel tired during your treatment. As the weeks of radiotherapy go on, you may feel increasingly more so. This may be because your body is using its resources to repair any damage to healthy cells caused by the radiotherapy.
It may also be because of all the journeys you’re making to and from the hospital.
Unfortunately, the feeling of tiredness doesn’t immediately stop once the treatment stops and may continue for a number of weeks afterwards.
Some people can get a rare side-effect where, a few weeks after treatment has finished, their tiredness becomes severe. This is called somnolence syndrome. However, it usually gets better on its own over a few weeks without any treatment.
Occasionally, some people will have a delayed onset of fatigue, up to five years after radiotherapy treatment. You can contact your GP or healthcare team if this happens to you.

Radiotherapy can temporarily slow the production of blood cells by the bone marrow. Low blood cell counts are usually not severe enough to cause major problems.

When there is a break from treatment for a few days, blood cell counts usually recover. However, the low levels can sometimes lead to anaemia, increased risk of infection and/or bleeding, such as bruising or nosebleeds.

If you’ve had radiotherapy to the brain and spine, or if you’re also having chemotherapy, you’re more at risk of these effects.

During or a few weeks after radiotherapy, some people develop changes to their skin in the area being treated, i.e. on your scalp. These can be like sunburn (red, blotchy and itching) in people with pale skin, and darkening of the skin in those who have darker skin.

As your skin will be more sensitive after radiotherapy, you should take care to protect it from strong winds and the sun. Always wear suntan lotion and a sunhat with neck protection when you’re outside.

Usually, the sensitivity will fade in the month or so after treatment. But you should keep using high factor sunscreen long-term on the areas of the skin that have had radiotherapy. This is because radiotherapy can permanently destroy the pigment producing cells in your skin. These cells enable you to tan and protect you from sunlight damage and developing skin cancer.

Your health team will be able to give you further guidance if you develop skin sensitivity.

Cognitive skills include thinking, memory, learning, concentration, decision-making and planning. They also include processing skills, such as recognising and making sense of information from your senses, particularly sight and hearing. If a large part or the whole of your brain is treated, there is a long-term risk of cognitive impairment. Read more about cognition and brain tumours.

Radiotherapy treatment that includes the pituitary gland at the base of the brain can affect the production of the various hormones that the pituitary controls.

This can cause a variety of symptoms related to functions such as body temperature, growth, salt and water balance, sleep, weight and appetite.

As part of your follow-up after radiotherapy, you may have blood tests to check your hormone levels, but if you notice any new symptoms, you should discuss them with your doctor.