Home > Services > Living with and beyond cancer > Cancer treatments > Radiotherapy

On this page:

Radiotherapy is a treatment where high-energy rays (called radiation) is used to kill cancer cells. It may be used in the early stages of cancer or after it has started to spread.

It works by damaging the DNA inside cancer cells, stopping them from growing or causing them to die. Healthy cells can repair themselves more easily, which is why radiotherapy is carefully planned to target cancer as precisely as possible.

It can be used to:

  • try to cure the cancer completely (curative radiotherapy)
  • make other treatments more effective. For example in combination with SACT or used before surgery (neo-adjuvant radiotherapy)
  • reduce the risk of the cancer coming back after surgery (adjuvant radiotherapy)
  • relieve symptoms if a cure is not possible (palliative radiotherapy)

We do not deliver radiotherapy at St George’s hospital, it is delivered in partner hospitals.

Please see the information on the Royal Marsden hospital website for details about the radiotherapy department and treatments offered.

Self-management tips

  • Stay hydrated by drinking 1.5-2 litres of fluid a day
  • Rest when needed, but try gentle activity such as walking to help reduce fatigue
  • Look after your skin in the treatment area, use unperfumed moisturiser and avoid rubbing or scratching
  • Avoid direct sun exposure to the treated area; use SPF 50 if outdoors
  • Wear loose, soft clothing to reduce irritation
  • Keep a symptom diary to track changes during treatment

Side effects of radiotherapy

Side effects vary depending on the part of the body being treated. Your cancer specialist team will explain the side effects most relevant to your treatment plan.

Common side effects include:

  • Tiredness (fatigue)
  • Skin discolouration, dryness, or peeling in the treatment area
  • Hair loss in the treated area
  • Sore throat or difficulty swallowing (for head and neck treatment)
  • Nausea or abdominal discomfort (for abdominal treatment)
  • Diarrhoea (for pelvic treatment)
  • Bladder irritation or needing to pass urine more often
  • Stiffness or discomfort in the treated area

Some side effects may appear weeks after treatment finishes. Your team will tell you what to expect.

How to ask for help

Before you start radiotherapy, your cancer specialist team will discuss with you about your treatment plan including timings of treatment and potential side effects.

If you are feeling unwell

If you are currently receiving radiotherapy treatment and experiencing side effects, please call the Royal Marsden Hospital Hotline on 020 8915 6899.

If you have completed radiotherapy treatment and experiencing side effects, please call your tumour specific Clinical Nurse Specialist (CNS) team.

If you are experiencing:

  • Sudden shortness of breath
  • A fever (temperature above 38°C or under 36°C)
  • Shivering episodes

Please call 999 or attend your nearest A&E department

Resources

For more information please see the Macmillan website and the resources developed by Macmillan