The law defines surgery as "structural change of the human body by incision or cutting into tissue for the purpose of diagnosing or treating diseases or disease processes by any tool producing localized alteration or transposition of living human tissue," however it does not... The law defines surgery as "structural change of the human body by incision or cutting into tissue for the purpose of diagnosing or treating diseases or disease processes by any tool producing localized alteration or transposition of living human tissue," however it does not limit that to an anatomical level. Many forms of treatment are considered surgical because they involve some type of alteration or transposition of tissue, such as: radiation therapy, chemotherapy, and various types of biological therapies. Some medical treatments do not meet this definition of surgery because they do not involve actual cutting of tissue. Examples include phototherapy (using ultraviolet light) and hydrosurgery (use of a water-filled high-pressure hand piece without a blade). However, many forms of non-invasive treatment have been coined "surgical" because of the dramatic results that can be achieved without requiring physical contact with the patient's body. These include: psychosurgery, which involves the permanent modification of the brain by neurosurgeons using electroshocks; and radiofrequency ablation (RFA), which uses heat to destroy cells.