What type of treatment does the term "radiation therapy" denote?

Radiation therapy refers to a medical treatment that utilizes high doses of radiation to kill or damage cancer cells. This form of therapy often involves the use of ionizing radiation, which can be generated from radioactive substances or high-energy rays. The primary objective of radiation therapy is to target and shrink tumors, making it a crucial element in the treatment of various cancers.

This differentiation is important when considering other medical terms. Thermal treatment involves the application of heat, which is not what radiation therapy entails. Electrical stimulation refers to the use of electrical impulses to promote healing or functionality, again different from the effects of radiation. Surgical removal pertains to the physical excision of tissue, which is a distinct approach from using radiation to treat a disease.

In summary, radiation therapy specifically denotes the application of radioactive substances or high-energy radiation to treat disease, making it the correct answer to the question presented.