Radiotherapy to the  rectum

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Radiotherapy is a localised treatment and side effects depend on the area of your body receiving the X-rays (in your case the rectum which is in the lower part of the abdomen - pelvis).

There are three main types of radiotherapy to the rectum:

Radiotherapy before surgery does increase the immediate post operative risks slightly - mainly increase risks of infection and delayed healing. Studies showed, however, at 6 months the complication rate with or without radiotherapy was similar. As in all types of radiotherapy, there are two types of side effects; those which come on during or immediately after treatment (acute side effects) and those which can be long term (late side effects). Your oncologist will have taken these into account when considering the benefits of treatment and will inform you of the side effects you are likely to get. Please discuss any concerns with your doctor, specialist nurse or radiographer at the time of consent or at any time during radiotherapy.

This information sheet provides a brief introduction to radiotherapy and explains the common side effects you may experience. This does not mean you will definitely get them. It is also possible you may experience a side effect not mentioned here.

Your first appointment
Your first appointment at the radiotherapy centre will be a planning session. This will either be in the simulator or the CT scanner. Report to the reception desk, show them your card, and they will direct you. You will then be welcomed by a specialist radiographer, who is the person who operates the machines to plan and give your treatment. Don't be embarrassed to ask him/her anything you are concerned about. The purpose of this visit is to plan and arrange your radiotherapy so you may not have a formal consultation with the doctor at this stage. Of course any urgent issues will be addressed but others should be saved for the regular consultations you will have during treatment. It is often difficult to judge exactly how long each patient will take - it is possible you may wait a long time.

The simulator or CT
The simulator is a machine which is a direct copy of a therapy machine. It takes X-ray pictures to enable the oncologist to decide the exact area of your abdomen which needs treatment. While very accurate measurements are taken, you will have to lie on a fairly hard couch which may be slightly uncomfortable. A small tattoo about the size of a pin head is made on your body - giving a permanent record of the measurements.

The treatment machine 
The treatment machine looks similar to the simulator. You will not be required to do anything you haven't already done in the simulator. Although the radiographers are not in the room while you are treated, you are being watched at all times on a camera. If you feel any distress, the machine can be turned off and the radiographers will be at your side within seconds. There is also an intercom which is left on. Treatment usually lasts only 1 to 2 minutes. You usually do not have any unusual sensations when the machine is turned on. After treatment you will not be radioactive and you will not lose the hair on your head.

Potential side effects:

Acute side effects 
Your appetite may be affected. If so, try to eat several small meals rather than three large meals a day. Drink lots of fluid - try to double your normal fluid intake. If you are worried about diet ask your radiographer to refer you to a dietician.

You may feel tired so it is important to get plenty of rest.

Your bowels may become loose later in the treatment, possibly causing diarrhoea. If this happens, cut down your intake of fruit, vegetables and fibre and try to increase your intake of eggs, milk and other dairy products. Report any diarrhoea to the doctor or radiographer as it may be necessary for you to have tablets. Take these until the diarrhoea improves and then reduce them. Your bowels should have returned to normal 2-3 weeks after treatment. You can then gradually re-introduce fibre into your diet until you are back on a normal diet  *** You should continue with your normal diet unless you begin to get diarrhoea.

You may experience pain on opening your bowels (rectal pain). Occasionally this may be associated with some blood in the stools.

If your bladder is in the treatment area, you may experience a feeling of wanting to pass urine more often (cystitis). It is still possible to develop a urinary tract infection so drink plenty of fluids and report any burning feeling, on passing urine, to your doctor.

A feeling of nausea or sickness may occur during treatment. Report any nausea or vomiting to your doctor as your symptoms can be relieved with anti-sickness tablets. For larger treatment areas you will be given an anti-sickness tablet to prevent nausea.

Your skin in the treated area may become red and sore, especially in the skin creases. You take a shower during your treatment but it is not advisable to sit and soak in a hot bath Avoid rubbing with a towel or scratching. If any soreness develops report this to the radiographer who will give you advise.

Potential late side effects 
The biggest risk of pre operative radiotherapy is delayed healing and infection following surgery. If not having immediate surgery, for most people, the acute side-effects will resolve within 1 month. However, rarely some continue to experience tiredness, diarrhoea, nausea, loss of appetite and cystitis for several months although these usually improve with time. Around 10-50% continue to have occasional diarrhoea and a few people may also notice occasional blood in the stools. Some people will notice that they have to pass urine more frequently than before radiotherapy. The majority of patients do not find these symptoms troublesome even if they persist indefinitely. A few people may experience more serious side-effects (less than 5%). These include narrowing of the bowel or bladder which may require an operation to correct the damage.

In males fertility may be affected, depending on the dose received. If relevant, sperm banking will be discussed with you. In women fertility will be affected if the dose to the ovaries is high. On no account must you be or get pregnant during radiotherapy as this will severely damage the baby. Radiotherapy may bring on, or reduce the time to, your menopause the specific risks of this will be discussed before treatment.


Additional general information  
The cancerbacup booklet "Understanding radiotherapy" can usually be obtained from the racks around the centre or alternatively by phoning cancerbacup directly on 0800 181199. A copy of the information film Chemotherapy & Radiotherapy can be ordered directly by email only hep@clara.co.uk


Further general information Your doctors and specialist nurses are in an ideal position to give you relevant information on your disease and treatment as they know your individual circumstances. Cancerbackup has a help line (0808 800 1234) and a prize winning video available in English, Italian, Urdu, Bengali, Gujarati & Hindi explaining Radiotherapy & Chemotherapy. Cancernet.co.uk has over 500 pages describing cancer, its management, practical tips and tool which patients, their carers and their doctors have found helpful during the cancer journey.


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