Scalp cooling is in the news since a couple of scientifically designed devices for this purpose have been cleared for marketing by the Food and Drug Administration (FDA) to reduce hair loss during chemotherapy. Scalp cooling is recommended for reducing alopecia in patients with any solid tumor.

Many chemotherapy regimens produce scalp alopecia, though baldness may also occur on other parts of the body. This is often short-lived, with the hair growing back again, but in societies which value a normal appearance highly, this is often among the most dreaded side effects of chemotherapy and even prevents some patients from accepting this treatment, according to Dawn Hershman of the Columbia University Herbert Irving Comprehensive Cancer Center.

For several years, from the 1970s onwards, scalp cooling was practiced using gel caps or wig liners which could be frozen before use, and even some conditioners claiming to cool the scalp. Cryogel helmets and other headgear which allowed cold air or liquid to move over the scalp were also offered. Ice packs, and cooled caps, which were replaced at regular intervals, have also been used. While they all proved to be of some benefit, many limitations were noted, such as inadequate fits, excessive weight, and intensive nursing input such as a nurse having to change the cryogel cap every half hour.

Modern Techniques of Scalp Cooling

At present, several modern devices have been tested in repeated clinical trials. These consist of caps that are properly fitted to the scalp, made of silicone to be light and soft, leaving the forehead and the ears exposed. They are designed to cool the head slowly, bringing down the temperature in regulated steps, while the scalp temperature is monitored by three separate sensors to make sure the skin is kept cool throughout.

The cooling cap is connected to an automated cooling regulator, and covered by a neoprene cap which insulates it and thus maintains the cooling effect. This means the nurse need not change the cap during the treatment session, making it more user-friendly. This has reduced the incidence of baldness caused by chemotherapy using multiple drugs from certain categories.
 

The degree of hypothermia achieved to the scalp must be preset, depending on the hair thickness, but is typically 5°C for thinner hair and 3°C for thicker hair. The cooling must begin 30 minutes before the drug is started, lasts throughout its administration and extends for 60-120 minutes after the drug is stopped.

Outcomes

Scalp cooling is most effective in patients with solid tumors who are on certain regimens of chemotherapy, with up to 65% reduction of alopecia, and less than 30% of the total number of patients eventually opting to wear a wig. Patients should always understand that it cannot prevent hair loss in 100% of patients. Moreover, for those who are on chemotherapy for indefinite durations, this would not be an appropriate choice due to the cost factor, and the lack of medical insurance coverage at present.

Significant hair loss typically follows the use of anthracyclines like doxorubicin, especially in combination with taxanes, as is usual with neoadjuvant and palliative chemotherapy. Some encouraging results suggest that hair loss is less following scalp cooling even with a combination of alopecia-inducing drugs. Around half of patients on combination chemotherapy including such drugs had a satisfactory drop in the rate of hair loss while hair was observed to regrow during the last part of the regimen. This might show that scalp cooling does protect the hair follicles from permanent harm.

How Does Scalp Cooling Work?

Cooling the scalp constricts the blood vessels that supply hair follicles in the scalp skin, which is thought to reduce the amount of the chemotherapy drug that reaches the follicles. Though some scientists feared an increased incidence of scalp metastases for the same reason, this has not been found to occur. Other factors also determine the extent of hair loss, as for instance whether the woman is pre- or post-menopausal, the presence of other disease conditions, other medications, nicotine habits and the original density of the hair follicles.

Some side effects may be expected, such as headaches because of the intense cold, discomfort in the head and neck, and pain if the cap has to be worn over long periods. Heating blankets or hot drinks may alleviate the coldness, while painkillers are needed in some cases.