Radiotherapy

WHY DO YOU NEED Radiotherapy?

If your tumour is in a position which makes surgery too risky to perform, radiotherapy may be used as a first line of treatment, usually in combination with Chemotherapy. For some people with low-grade gliomas, these treatments may be offered soon after diagnosis; for others it could be that their tumours are stable enough for years to pass by on the “watch and live” treatment plan of regular MRI scans before any radiotherapy is offered.

If your tumour is suitable for surgery, it is not guaranteed that all of the tumour cells can be removed completely without interfering with normal brain structures and running the risk of causing permanent damage; so the surgeon will stop when he considers further surgery to be too risky, and you will have experienced a “partial resection”. Unfortunately, even if the entire tumour seems to have been removed (a “complete resection”) small cells may remain behind, which are not able to be detected at the time. Brain surgery can usually be undertaken on more than one occasion if your tumour grows back (we have people on our online support group who have had surgery 2 or 3 times), but there may come a time when your Neuro-oncologist recommends radiotherapy as the next line of treatment.

Some tumours are very sensitive to radiotherapy and the hope is for a cure. Other tumours are less sensitive to it, and in such cases it may not be possible to cure, but radiotherapy will usually bring relief of symptoms and prolong life. For example, you may notice a considerable reduction in the frequency and severity of seizures; or a lessening of mobility problems. However all radiotherapy to the brain carries a risk of side effects, some of which may be temporary and others permanent.

Your neuro-oncologist will advise when is the best time for you to consider radiotherapy, as it can usually be used only once. However exceptions to this are:

• if your first radiotherapy treatment was a number of years ago (for example 10 years ago)
• if a Brain Tumour arises in a different part of the brain and can be treated by another form of radiotherapy such as stereotactic radiotherapy (gamma knife)

WHAT IS CONVENTIONAL RADIOTHERAPY?

Radiotherapy is the use of high energy x-rays to destroy tumour cells whilst doing as little harm as possible to surrounding normal cells. For various reasons the cells that grow and divide quickly are much more sensitive to radiation than nondividing, resting cells.

In the brain most normal cells and certainly the important nerve cells (neurons) do not divide. This means that radiotherapy will be much more damaging to the tumour than to the surrounding brain. Nevertheless a great deal of trouble is taken to minimise the amount of normal brain irradiated.

HOW IS CONVENTIONAL RADIOTHERAPY GIVEN?

Radiotherapy is given in a course of daily treatments called 'fractions'. It is given at different intervals; daily, twice daily or every few days. The number of fractions or daily treatments will depend on your tumour type and fitness. Your doctor will plan the treatment individually for you taking all the factors into consideration. Radiotherapy is painless. You will not feel anything during your treatment.

PLANNING CONVENTIONAL RADIOTHERAPY

Before the radiotherapy can begin, the exact treatment plan, the radiotherapy dose, the number of fractions and the amount of brain that will be treated is decided by the radiotherapist. A radiotherapist is a doctor who specialises in the treatment of tumours using radiotherapy. The treatment plan varies depending on the type of tumour.

Your First Visit for Conventional Radiotherapy

Your first appointment will be to the mould room. To ensure that the radiotherapy is treating exactly the same area and that your position on the couch is the same each time, a perspex mask is made. This is called a shell. It allows your head to be kept in the same position and helps to stop it moving during the treatment. Marks can be drawn on it, instead of on your skin in order to line up the treatment machine. The mask is applied before each fraction of radiotherapy and removed immediately afterwards.

An impression of your head and face is taken in the position that you will be in for your treatment in order to make the shell. This could be lying on a couch on your back, on your side or even lying on your stomach. The impression is obtained using some strips of plaster of Paris bandage. Once the bandage starts to set it is removed and you can leave. The procedure takes about 20-30 minutes. Behind the scenes the mould room technician makes a plaster cast using this impression and a sheet of thin transparent perspex is then moulded over this plaster cast. An alternative is to use a plastic sheet which can be moulded when warm.

The shell needs to fit quite closely and it helps if you are relaxed during the taking of the impression. It does not hurt but most people say it becomes a little hot under the plaster bandage.

The next step

Your next visit will be to the simulator machine. This is a special x-ray machine that can take films and reproduce the movements of the treatment machine and therefore 'simulate' the position of the x-ray beams that will be used for your treatment. You will need to lie in the treatment position wearing your newly made shell. The radiotherapist with the help of a radiographer plan the position of the radiotherapy beams using information from scans, operation and previous examinations. This session lasts about 30 minutes. It is often much longer than the treatment time on the machine. At the end of this simulator session you will be given a date and time for starting treatment. This may be a few days later.

Whether you will be receiving radiotherapy as an outpatient or an inpatient will depend on how fit you are and your ability to travel. Your doctor will discuss this with you and make specific arrangements. You will be given a fixed appointment time for your treatment and every effort is made to keep closely to these times. However inevitably, occasionally, there will be some delays.

While some people find the shell and treatment machines intimidating at first, you cannot feel the radiotherapy and there is no discomfort during treatment. You are not radioactive and there is no need to take any special precautions for the safety of others. You are not a hazard.

The side effects depend on how much of your brain is being treated or if the spinal canal has to be treated as well. Most side effects are quite mild and all efforts are made to minimise them. However, some are inevitable.

Early side-effects

• Hair loss: You will lose your hair in the area irradiated. Hair starts to fall out between the second and third weeks of treatment and will usually have grown back to its maximum extent by 3-6 months. Sometimes hair loss is permanent or the regrowth is only partial. Also when the hair regrows it may be a slightly different colour, curlier and usually finer than it was before the radiotherapy. The part of your head affected will depend on the actual radiotherapy field arrangement, but for most people it will be such that a wig or hat will be required. Wigs are supplied on the National Health Service, and your doctor or nurse will make arrangements for a fitting. Ladies often wear turbans, scarves and hats. Wigs are available for men. However most prefer to wear a hat, cut their hair very short or even shave their head. At the start of radiotherapy you may be advised to change your hair care routine. The use of shampoo and other hair care products may not be recommended and should be discussed with your doctor, nurse or radiographer.
  

• Skin changes: You may notice some skin changes in the area being treated. After about 3 weeks it may redden and become itchy and darkened, as sunburn does. Do not try and treat this by yourself. Check with your doctor, nurse or radiographer for advice on how to care for your skin. For example you will probably be advised to avoid the use of cosmetics and creams on the treatment area. It is also important that your head is protected in the sun with a hat. You should continue this practice for some years after the radiotherapy has finished. It is Iikely that the skin in the treatment area will be more sensitive to the sun.

• Tiredness: Most people will feel tired and a little sleepy towards the end of their course of radiotherapy. A sleep in the afternoon and periods of rest can help you cope with the tiredness. This feeling of tiredness can last for a few weeks. Additionally some people experience a period of increased tiredness around 6 - 10 weeks after radiotherapy has finished. Should this happen to you it is advisable that you inform your doctor.

• Nausea: Very rarely people feel sick. This usually lasts just a few hours after treatment. For example, if your treatment is at 9am, you may feel queasy and not have much appetite for lunch, but by dinner time you are hungry again and ready to eat. Alternatively, it may be helpful to eat small but frequent meals throughout the day. Avoid fatty foods and keep your diet bland if you are feeling sick. If it is troublesome and persistent please tell your doctor as anti-sickness tablets can be prescribed and are effective.

• Weight: You may find that your weight has increased, especially if you have been on steroid tablets. In this case it is probably best to eat sensibly. Either way your doctor, nurse or Dietician can give you advice.

• Blood count: The blood count is not usually a problem unless the spinal canal is being treated as well as the head.

Later side-effects

There are some side-effects that can develop many months or years after the radiotherapy. The degree and frequency will depend on the dose given, the amount of normal brain treated and sometimes the particular site of the brain that has been treated. If, for instance, the pituitary gland or the hypothalamus receives a high radiotherapy dose, regulation of some of the hormones can be upset. This may lead to a loss of periods, or sexual function and sometimes an underactive thyroid. However all of these can be treated by hormone replacements.

Most people are concerned about the effect of radiotherapy on their intelligence. Some damage to the normal brain will be inevitable. It must be remembered however that the tumour itself may cause damage and the best balance must be achieved between treatment effectiveness and side effects. All attempts are made to minimise radiotherapy injury to normal tissues and there are many people surviving well with normal life styles many years after treatment. If there is no tumour recurrence, many individuals can retain their ability to work and function within the lifestyle that they enjoyed before their illness began.

WHEN WILL I BEGIN TO NOTICE RESULTS FROM THE RADIOTHERAPY?

The brain is not efficient at clearing away dead tumour cells. The radiotherapy also interferes with the tumour's ability to grow by damaging its reproductive cycle. Therefore cells die gradually over a period of time. It may therefore be several months or even longer before the full effects of therapy are realised.

The results of scans taken during this time are often confusing. This is because of swelling caused by the treatment. Dead cells often appear as a mass larger than the original tumour. This mass may cause symptoms similar to the tumour.

Don't be disappointed if the first scans do not show shrinkage of the tumour. The combined effects of your surgery and radiotherapy may mean that the positive results that you hope for will not be obvious for a while. The changes expected may show up on a later scan.

What is important is how you feel and whether there is improvement in your function and disability.

AFTER THE TREATMENT

While you are undergoing any form of treatment, you have a specific goal in mind and specific activities that have to be performed. Once treatment is over you may experience a number of different emotions, ranging from relief to have come through it all, to a sense of loss of control or structure to life. It may be a few weeks before you have to see your doctor and it may feel as though there is nothing to be done until then.

However you can still take an active role in your recovery. Aim to rest and allow your body to heal. Take gentle exercise. Eat well. Simply take time to enjoy the people and the world around you. Use whatever support and complementary therapy treatments feel right for you at this time.

However do of course keep appointments for tests and check ups, and contact your doctor or nurse if you have any questions or notice any changes you think are important and are of concern.

Sources:

1. http://www.radiologyinfo.org/en/info.cfm?PG=thera-brain RadiologyInfo™ is the public information Web site developed and funded by the American College of Radiology (ACR) and the Radiological Society of North America (RSNA).
   
2. Brain Tumour UK

More information about different types of radiotherapy used to treat brain tumours can be found in this section.