American Shared Hospital Services provides Gamma Knife stereotactic radiosurgery equipment and radiation therapy and related equipment to approximately 20 medical centers in approximately 20 states in the United States. The Company provides Gamma Knife services through its over 81% indirect interest in GK Financing, LLC (GKF). The Company's business is the outsourcing of stereotactic radiosurgery services and radiation therapy services. The Company provides the equipment, as well as planning, installation, reimbursement and marketing support services. The Company's radiation therapy business consists of one Image Guided Radiation Therapy Operations (IGRT) system. IGRT technology integrates imaging and detection components into a linear accelerator, allowing clinicians to plan treatment, verify positioning and deliver treatment with a single device, providing radiation therapy with less damage to healthy tissue. It is also engaged in proton beam radiation therapy business (PBRT).