MODEL RELEASED. Radiotherapy. Woman's head undergoing radiotherapy treatment on a skin cancer. She has a lead block on her eye and cheek to protect the healthy cells from the radiation. The lead is covered in cling film because it is toxic on contact with the skin. The woman is being treated for a basal cell carcinoma, one of the most common skin cancers. The device at upper left focuses X-rays on the skin cancer. Radiotherapy works as the ionising radiation produced slows or stops altogether the growth of abnormal cells. Most skin cancers can be completely cured by this method.