Radiotherapy
Radiotherapy treats cancer by using high
energy rays which destroy the cancer cells, while doing as
little harm as possible to normal cells.
Radiotherapy is used in a
number of circumstances to treat cancer of the colon and
rectum.
Adjuvant
radiotherapy
Adjuvant radiotherapy
is used to treat cancer of the rectum, if it is thought there
may be cancer cells left in the pelvic area after surgery that
are too small to be seen. It is not normally used for cancer
of the colon.
Neo-adjuvant
radiotherapy
Radiotherapy
is sometimes given as a neo-adjuvant therapy (given before
surgery) for patients with cancer of the rectum when the
tumour is large or fixed. This treatment is given to reduce
the size of the tumour and make the operation easier to carry
out.
Radiotherapy for
secondary cancer
Radiotherapy
may be used to shrink the cancer if it has recurred,
particularly in the pelvic area, and to relieve symptoms, such
as
pain.
Planning your
treatment
Radiotherapy
is given in the hospital radiotherapy department. The course
is usually in five sessions from Monday to Friday, with a rest
at the weekend. The length of your treatment will depend on
the type and size of the cancer. Your doctor will discuss the
treatment with you.
To ensure that you
receive maximum benefit from your radiotherapy, it has to be
carefully planned. On your first few visits to the
radiotherapy department you will be asked to lie under a large
machine called a simulator, which takes X-rays of the area to
be treated. Sometimes a CT scanner can be used for the same
purpose. Treatment planning is a very important part of
radiotherapy and it may take a few visits before the
radiotherapist, the doctor who plans your treatment, is
satisfied with the result.
Marks may be drawn on
your skin to help the radiographer, who gives you your
treatment, to position you accurately and to show where the
rays are to be directed. These marks must remain visible
throughout your treatment but they can be washed off once your
course is over. At the beginning of your radiotherapy you will
be given instructions on how to look after the skin around the
area to be treated.
Before each session of
radiotherapy, the radiographer will position you carefully on
the couch, either sitting or lying, and make sure you are
comfortable. During your treatment, which only takes a few
minutes, you will be left alone in the room, but you will be
able to talk to the radiographer who will be watching you
carefully from an adjoining room. Radiotherapy is not painful
but you do have to be still for a few minutes while your
treatment is being given.
Side effects
Radiotherapy
to the bowel area sometimes causes side effects such as
nausea, vomiting, diarrhoea and tiredness. Some people also
find that they pass urine more often than usual. These side
effects can be mild or more troublesome, depending on the
strength of the radiotherapy dose and the length of your
treatment. However, most of these can be easily treated with
drugs, so it is important to tell your doctor if you are
having any problems.
Nausea can usually be
effectively treated by anti-sickness drugs (called
anti-emetics), which your doctor can prescribe. While you are
having radiotherapy it is important to drink plenty of fluids
and maintain a healthy diet.
If you don't feel like eating, you can replace meals with
nutritious, high-calorie drinks which are available from most
chemists and can be prescribed by your GP. CancerBACUP's
booklet Diet and
the cancer patient has some helpful hints on how to
eat well when you are feeling ill.
All these side effects
should disappear gradually once your course of treatment is
over, but it is important to let your doctor know if they
continue.
Radiotherapy does not
make you radioactive and it is perfectly safe for you to be
with other people, including children, throughout your
treatment.
CancerBACUP publishes a
booklet called Understanding
radiotherapy, which gives more details about this
treatment and its side effects.
