Radiotherapy is almost always a local treatment, limited to a particular part of the body. Only the skin in that area will be irradiated and the skin elsewhere will not be affected.

The doses of radiotherapy used can vary but even with quite high doses modern radiotherapy machines usually cause a little skin irritation. Even so this does mean that the skin which has been irradiated will be more sensitive to sunlight than your normal skin.

The degree of sensitivity will vary from person to person. The increased sensitivity also reduces gradually with time but probably never disappears completely.

Having had radiotherapy does not mean you must avoid the sun completely but you should take care over exposing the treated skin. It is very important to cover the treated area for at least the first year after radiotherapy. Wear clothing made of cotton or natural fibres which have a closer weave and offer more protection against the sun. Even after this time the area treated will be more delicate, so extra care should be given. You should also use a high factor sunscreen (of at least factor 15). Remember, too much sunbathing does carry the risk of leading to skin cancer and should be avoided.

Very occasionally radiotherapy is given to the whole body. In this situation the doses are normally quite low but you should still take precautions in exposure to strong sunlight. Seek advice  from your doctors if you are having this type of treatment.