American Shared Hospital Services provides technology solutions for stereotactic radiosurgery and advanced radiation therapy equipment and services. It operates in two segments, Leasing and Retail. The company leases nine Gamma Knife systems and one proton beam radiation therapy (PBRT) system; and provides planning, installation, reimbursement, and marketing support services. It also owns and operates two single-unit Gamma Knife facilities that provides radiosurgery services directly to the patient. The company markets its solutions to cancer treatment centers, health systems, and cancer networks worldwide. American Shared Hospital Services was founded in 1980 and is based in San Francisco, California.