American Shared Hospital Services engages in leasing radiosurgery and radiation therapy equipment to healthcare providers. Its equipment includes Gamma Knife, PBRT, and IGRT. It operates through the Leasing and Retail segments. The Leasing segment focuses on the provision of radiation therapy through medical equipment leasing. The Retail segment delivers direct patient services. The company was founded by Ernest A. Bates in 1977 and is headquartered in San Francisco, CA.