Radiotherapy for anus and rectum cancers

Although you may have heard about radiotherapy from friends, relatives and/or other patients, it is important to remember that their experience may not be the same as yours. In all cases, a doctor will explain your radiotherapy treatment to you and answer any questions you may have. 

We are here to help, so if you would like further information or have any concerns, please do not hesitate to ask a radiographer or a member of the radiotherapy review specialist team. 

In most cases, a friend, relative or carer may accompany you to your appointments. This will depend on any infection control guidelines currently in place. Please ask your doctor or a member of the radiotherapy team if this is possible.  

What is radiotherapy?

Radiotherapy uses precise, carefully measured doses of high energy x-rays to treat cancer. Cancer cells are more sensitive to radiation than normal cells, so the aim of treatment is for the x-rays to either destroy the cancer cells or stop them from growing, whilst avoiding and protecting the normal cells as much as possible.  

Radiation also damages normal cells in or around the area being treated which causes side effects, but these will usually recover and heal after treatment.  

Why use external beam radiotherapy to treat anus and rectum cancers?

Radiotherapy may be given to treat and attempt to cure anus and rectum cancers (radical radiotherapy) as an alternative to surgery. Surgery may be reconsidered later if the cancer returns, so you will be monitored after the radiotherapy treatment course finishes.  

Radiotherapy is sometimes used following surgery if this becomes necessary. It can also be used immediately before a planned surgery.  

You will need to attend the radiotherapy department as an out-patient, for a course of daily treatments (Monday to Friday), over a period of one to six weeks. 

Radiotherapy may also be used to relieve symptoms from anus and rectum cancers when the cancer has spread outside the site where it started to other parts of the body (palliative radiotherapy). This would be a shorter course of treatment, with the aim of controlling symptoms and minimising side effects. 

Chemotherapy

Some patients may receive a course of chemotherapy (where medicine is used to kill cancer cells) prior to radiotherapy, called induction chemotherapy. Chemotherapy may also be given during radiotherapy (chemo-radiation), to try to make cancer cells more sensitive to radiation. Both are given as an out-patient treatment. If you require chemotherapy with your radiotherapy, you will need weekly blood tests while you are on treatment, which are usually taken on a Friday morning.  

Chemotherapy may increase the risk of side effects, particularly infection and bleeding, and so will not be recommended for all patients. The chemotherapy team will give you specific information leaflets on chemotherapy if it is recommended.  

Some chemotherapy is given as an injection or infusion on selected days of your radiotherapy. This is normally given on one of the wards at the Royal Free Hospital. It is important on the days where you have this type of chemotherapy that you have your radiotherapy within one hour of the chemotherapy finishing. Please come directly to the radiotherapy department afterwards. 

Some chemotherapy is given in the form of a tablet. This will normally be given to you by a pharmacist in the radiotherapy department on your first day of treatment. These tablets are usually taken daily, however specific instructions for you will be provided by the doctor and pharmacist. Sometimes the tablet can be given as well as a chemotherapy injection.  

Your radiotherapy planning appointment

Prior to your radiotherapy treatment starting, you will need to attend the radiotherapy department for a CT planning scan.  

Before the scan, you will be asked to ensure your bowels are empty and your bladder is full. This will be fully explained in information given to you beforehand.  

This is important as both the bowels and bladder are immediately next to the treatment area inside the pelvis (the area of your body between the stomach and the legs). They need to be in the same position for the planning scan and for each day of your treatment so that the radiotherapy is as accurate as possible. 

Bowel preparation

We will ask you to ensure your bowels are empty each day before your scan and treatment. We will not usually give you anything to assist with this and will instead ask you to attempt to go to the toilet naturally. We ask that you do not strain or take anything to assist with this. If you are struggling, discuss this with your radiographer on the day of your appointment.  

Steps to help reduce intestinal gas:

• ensure regular meals
• eat slowly and chew food well
• drink approx. 1.5 - 2 litres of fluid a day (8-10 glasses)
• keep active.

Bladder preparation

It is important that your bladder is full. This minimises the amount of your bladder that is near to the area we are directing treatment at. This means that less of the bladder will be affected by the treatment, reducing your side effects.  

Your radiotherapy treatment appointments

Radiotherapy treatment is like having an x-ray or scan. You will need to follow your specific bowel and bladder preparation schedule prior to each appointment. Each session takes approximately 15 minutes, most of which is spent ensuring you are in the correct position. The delivery of the radiation treatment lasts only a few minutes.  

Sometimes it can take longer if your internal organs are not in the correct position. On rare occasions we may not be able to proceed with your treatment if we cannot be confident that it is going to be as accurate as needed.  

Short-term side effects

Some side effects only last for a short time, usually peaking about two to three weeks after you finish your treatment and then taking a further two to three weeks to improve. However, this will not be the case for all patients. Possible short term side effects from radiotherapy for anus and rectum cancers are: 

Bladder irritation

Radiotherapy may cause part of the bladder to become irritated. This may cause you to want to pass urine more frequently and experience a burning sensation while doing so.  

Please aim to drink plenty of fluids (two litres/three pints, per day) but avoid acidic drinks (e.g. fruit juices and sugary drinks), alcohol, fizzy drinks, or drinks with caffeine (e.g. tea, coffee) that can make these side effects worse. Drinking more through the day and less in the evening may help you to pass less urine at night.  

Bowel irritation

The bowel may become irritated, and you may experience some diarrhoea. Please let us know if this happens, so we can help you manage this effectively. You may also experience an increase in the frequency of needing to empty your bowels and an increased sense of urgency. In some cases, you may experience pain when emptying your bowels and find that you are passing more mucus or wind.  

Loss of pubic hair

You may lose some pubic hair. This often grows back but may be thinner and/or a different texture than before. 

Discolouration of skin

Your skin may become discoloured in the treated area. We advise you not to soak in hot baths, to use a mild, non-perfumed soap and to pat the area dry rather than rubbing. Please do not use talcum powder or any lotions and creams other than those advised by us. Please ask one of your radiographers for information on this.  

Tiredness

You may become tired. Gentle exercise may help but save your energy for activities you enjoy doing. 

You may experience some, or all, of these side effects. Please always let the radiotherapy team know of anything worrying you, as we want to help you recover as soon as possible. 

Long-term side effects

Some side effects are long term. These usually occur for more than three months but can sometimes last much longer after finishing your course of treatment. 

Bladder and bowel function

There is a potential risk of permanent damage to the bladder and bowel, for example: 

• The bladder may not hold as much urine as before, so you may need to pass urine more frequently. 
• Bowel movements may become more loose or frequent than before. Rarely, you may experience diarrhoea. 
• Blood vessels in the bladder or bowel may become more fragile and you may notice blood in your urine, or poo. 

Please let your doctor know if you experience any of these side effects as you may require additional tests. There may also be treatments that can help. 

Fertility and sexual function

Common side effects are listed below, but please discuss your individual experience with your doctor or radiotherapy review specialist: 

• Women might find their vagina becomes dry and tight, but we can advise you about ways to minimise this. Women are also at risk of early menopause. Please talk to your doctor if this is a concern for you. 
• Men may lose their ability to have an erection. There are different treatments available, which may help. 
• Radiotherapy to the anus or rectum is likely to make you infertile (not be able to have children). We do not recommend that you try to have children during your radiotherapy. You should use barrier contraception during treatment and for three months afterwards. Your doctor will discuss this with you before you start treatment.  
• Your rectum will be sensitive during and after radiotherapy and can become tight. We ask that you refrain from receptive anal sex during and immediately after your radiotherapy treatment. If the long-term impact of this is a concern to you, please speak to your doctor.  

After your treatment

You may be referred back to your surgeon for follow up care or your radiotherapy doctor, depending on the treatment you have received.  

Usually, you should expect an outpatient appointment to be arranged for four to six weeks after completing your treatment. This may sometimes be a telephone appointment. Outpatient appointments will then continue a three to six monthly basis, or more frequently if required.