Brachytherapy (from the Greek word βραχύς brachys, meaning "short-distance"), also known as internal radiotherapy, sealed source radiotherapy, curietherapy or endocurietherapy, is a form of radiotherapy where a sealed radiation source is placed inside or next to the area requiring treatment. Brachytherapy is commonly used as an effective treatment for cervical, prostate, breast, and skin cancer and can also be used to treat tumours in many other body sites.