Scalp cooling is a method of reducing the loss of hair from the head, which occurs during treatment with some chemotherapy drugs.

Each hair on our bodies grows out of a hair follicle. Small blood vessels in the scalp supply the cells of the hair follicles with food and oxygen and carry away waste products. Any chemotherapy drugs in the bloodstream will also be carried to the hair follicles.

When blood vessels in the scalp are cooled they become smaller, and so less blood flows through them. Cooling the scalp during chemotherapy means that less of the chemotherapy drug reaches the hair follicles, and so the hair is less likely to fall out.

There are two widely available methods for scalp cooling:

• One method uses a hat known as a 'cold cap', which is filled with a gel that can be chilled. The hat must be fitted snugly around the head to work properly.

• The other method of scalp cooling uses a small refrigerated cooling system to pump a liquid coolant through a cap that is attached to a specially designed refrigerator.

Scalp cooling is not suitable for everyone.

It is not suitable:

• When there is too high a risk that cancer cells could survive in the blood vessels of the scalp and could cause the cancer to come back after treatment.
• For some people needing very high doses of chemotherapy, as scalp cooling is less likely to work with very high doses of the drugs.
• For some chemotherapy treatments where the drug stays in the body for a long time: for example, if you are having continuous treatment through a pump. This makes it impractical to have scalp cooling.
• For some patients whose liver is not working as well as it should. This might lead to the chemotherapy drugs circulating in the body for longer than usual, and it may not be possible to keep the scalp cold for long enough.

Some doctors worry about using scalp cooling with treatment that aims to cure the cancer, as they fear that cancer cells may be more likely to survive the chemotherapy than if it were not used. Some patients do not feel comfortable with scalp cooling for the same reason. For other people not losing their hair may be the most important aspect of their treatment.

Scalp cooling is most likely to be effective with:

• cyclophosphamide
• daunorubicin
• docetaxel (Taxotere®)
• doxorubicin (Adriamycin) 
• epirubicin (Pharmorubicin®)
• paclitaxel (Taxol).

For scalp cooling to work, your scalp needs to be cold for up to 30–40 minutes before your chemotherapy drugs are given – and for some time afterwards. Your scalp temperature needs to be kept low for the whole time the drugs are circulating in your blood.

If you are having your chemotherapy as an outpatient, you may need to spend up to one and a half hours longer at the hospital for each treatment.

Some people find that the ice pack and gel-filled hats feel heavy to wear. When using this type of hat you are usually free to walk about once your chemotherapy has been given. However, your hat will need to be changed every 20–40 minutes to keep your scalp cool, so you cannot go too far from the chemotherapy department.

Caps attached to the cooling machines generally feel lighter than the frozen caps. You will need to sit by the machine while the cap is in place, so you cannot walk about freely with this method; however, the cap can be disconnected for short periods if necessary, for example if you need to use the toilet. These caps do not need to be changed as the machine is continuously cooling the liquid circulating round your scalp.

You will probably feel chilly when having scalp cooling and may need to wear a warm jumper. Hot drinks will help you to feel warmer. You may get a headache during scalp cooling, especially in hot weather.

Scalp cooling can be very effective in preventing or reducing the loss of your hair. But you will not know how well it will work for you until you try it. It can help not to wash your hair for at least 24 hours after having scalp cooling.

Despite scalp cooling, you may find that your hair thins slightly. Unfortunately, some people who have scalp cooling will still lose their hair.

Scalp cooling protects only the hair on your scalp. Body hair (including eyelashes, eyebrows, beards and moustaches, chest hair and pubic hair) may be lost.

Any hair loss caused by chemotherapy is temporary, and once the treatment is over, your hair will start to grow back. At first, the hair is very fine, but you will probably have a full head of hair after 3–6 months. You may find that your new hair is curlier or more coarse than it was before, or it may be a slightly different colour.

If you are interested in scalp cooling you will need to discuss this with your doctor or nurse, who can advise whether it is suitable for you.

This section has been compiled using information from a number of reliable sources including:

• Martindale: the Complete Drug Reference (35th edition). Sweetman et al. Pharmaceutical Press, 2007.
• British National Formulary (56th edition). British Medical Association and Royal Pharmaceutical Society of Great Britain, September 2008.

For further references, please see the general bibliography.