Targeting cancer - Radiation therapy treatment process
Targeting cancer - Radiation challenges and what helped
Targeting cancer - How the radiation immobilisation mask is made
Targeting cancer - Side effects of radiation therapy

Radiation therapy

The most common radiation therapy approach for nasopharyngeal cancer is called external beam radiation. This type of radiation therapy applies radiation from outside the body.

Radiation therapy may be given using:
  • Intensity modulated radiation therapy (IMRT) or Volumetric arc therapy (VMAT) or Tomotherapy, which use different ways to deliver radiation very precisely, minimising the radiation that gets to healthy parts of the body surrounding the cancer.

  • Stereotactic radiation therapy, which delivers a large and precise dose of radiation in one or a few visits. It can be used as part of radiation therapy to increase the dose of radiation to the nasopharynx cancer. It is sometimes used to treat cancer that has come back.

Radiation therapy can be used in the following ways: 
Definitive  Definitive radiation therapy is the main treatment for nasopharyngeal cancer. It is used without surgery to cure nasopharyngeal cancer. Typically radiation therapy is delivered daily (but not on weekends) over 7 weeks. Sometimes chemotherapy is added to radiation therapy (chemoradiation) to make it more effective.
Palliative In cases where a cure is not possible, radiation therapy is used to relieve symptoms of advanced nasopharyngeal cancer. Symptoms that may require palliative radiation therapy include pain, bleeding and pressure symptoms from the tumour pressing on vital structures (e.g. visual disturbance and headaches).

How do I prepare for radiation therapy? 

You will meet with many members of the cancer care team, who will help you learn how to look after yourself through radiation therapy, recovery and long term follow-up. They will also talk to you about side effects and how to manage them. It may be helpful to write down questions as they come up, so you can ask anyone in your cancer care team when you see them.  

Radiation therapy mask-making and simulation 

  • Radiation therapy is a precise treatment. In order to make sure, that the cancer is covered by the treatment, you will need to be very still during the treatment, usually for about five minutes. A radiation therapy mask that is made to fit perfectly to your shape, will be put on you during each treatment to help the machine target where the cancer is.
  • You will have a planning CT scan (and sometimes other scans) with the mask on. Your radiation oncologist and radiation therapists will use these scans with all your other clinical information to develop a radiation therapy plan just for you (a personalised plan). Your plan will be checked by the radiation therapy and radiation oncology physics team before it is ready to be used for your treatment. This whole process can take approximately 2-3 weeks.
 

Teeth and mouth care

You might need to have some of your teeth taken out, this will depend on the area being treated and the dose of radiation therapy. It is important to take out any broken or infected teeth before radiation therapy. Taking out unhealthy teeth after radiation therapy can cause problems with the jaw bone.

 

 

Diet, nutrition and the role of your dietitian

Your cancer and its treatment can make it hard to eat and drink. Your doctor will recommend you see a dietitian to maximise your nutrition during treatment as well as while you are recovering. Sometime feeding tubes may be recommended depending on the area being treated and the dose of radiation therapy.
There are two common types of feeding tubes: 

  • Gastrostomy tube (sometimes called a PEG tube): this type of tube is inserted through your abdominal wall into your stomach, with part of the tube staying outside the stomach.  A syringe can be attached to the tube to give you food this way if needed. The tube is inserted using a camera through the mouth into the stomach (gastroscopy) or using a CT scanner to guide insertion directly through the skin. If a PEG tube is needed, your doctor will organise this before starting your radiation therapy

  • Nasogastric tube: this type of tube goes through the nose down into the stomach and is usually used for short periods (days or weeks). A nasogastric tube can be inserted at any time (before, during or after treatment).

 
 

Speech, voice and swallowing
 

Your cancer and its treatment can make swallowing and speech difficult. Your doctor will recommend you see a speech pathologist, who can help you with ways to manage swallowing and communication difficulties, during and after treatment.

 

 

There are many other aspects of supportive care that are available, ask your doctor if you have any specific needs.

Side effects

The side-effects of radiation therapy start around two weeks into treatment and progress through treatment to peak in the last week or just after treatment ends. The side effects start to improve 2-3 weeks after the end of treatment.

Side effects associated with radiation therapy depend on:
  • the dose of radiation therapy

  • the area being treated

  • whether or not chemotherapy is added to the radiation.

Each person responds to radiation therapy differently. Some people may experience a few side effects while others may not experience any at all. The following are some common side effects of radiation therapy.
  • tiredness

  • skin irritation in the treated area e.g. redness, dryness and itching, weeping skin, scaling or sometimes skin breakdown (sores)

  • nasal irritation, blockage and crusting

  • ​ulcers in the mouth and throat that make it painful or difficult to chew or swallow

  • sticky or thick saliva

  • altered taste, which is usually a loss of taste or, sometimes, an unpleasant taste in the mouth​

  • blocked ears from inflammation within ear canals.​

Most side effects are short lived and may go away within 4–6 weeks of finishing radiation therapy. Some side effects may last for months after you finish radiation therapy and some may be permanent.

Long-term side effects of radiation therapy include:

  • dry mouth (called xerostomia) and difficulty eating dry food such as bread/biscuits due to lack of saliva. With modern radiation techniques, some recovery of saliva may be expected up to two years after radiation therapy

  • inability to eat certain foods, in particular sensitivity to spicy or acidic foods

  • gum and tooth problems from lack of saliva 

  • crusty nasal discharge

  • worse hearing or deafness may occur, although with modern radiation therapy techniques the risk of this side effect can be greatly reduced

  • underactive thyroid gland

Rare side effects from nerve damage (called cranial neuropathy) may occur following treatment of very advanced cancers. These include difficulty speaking, swallowing, impaired and double vision. This is because the nasopharynx is very close to a number of important parts of the nervous system (e.g. spinal cord, brain and nerves) involved with seeing, hearing and balance. 

The risk of these rare side effects is very low and with modern radiation therapy techniques, your radiation oncologist will be very careful to avoid these structures by using very precise radiation therapy techniques. You can talk to your radiation oncologist to find out if these concerns apply to your situation and to find out more about these rare side effects.

Once your radiation therapy ends, you may continue to have follow-up appointments so that your doctor can check your recovery and monitor any side effects that you may have. Usually your doctor may arrange for a PET scan about 12 weeks after finishing radiation therapy to make sure the cancer has completely gone.

Your doctor may recommend that you receive specific supportive care to help during your treatment and recovery.