AMERICAN SHARED HOSPITAL SERVICES (AMEX:AMS), a leading provider of turnkey technology solutions for advanced radiosurgical and radiation therapy services, today shared a recent announcement from Mevion Medical Systems, Inc., formerly Still River Systems, Inc., regarding a $45 million investment in Mevion by a group of leading private venture capital firms. Mevion is the manufacturer of the MEVION S250 Proton Therapy System. After this funding, AMS will own approximately 1% of Mevion. AMS is developing proton therapy centers in Boston (Tufts Medical Center), Orlando (Orlando Regional Healthcare) and Long Beach, California (Long Beach Memorial Medical Center) which are expected to employ the MEVION S250 proton therapy device: Leading Private Venture Capital Firms Invest $45 Million in Mevion Medical Systems LITTLETON, Mass., Jan. 24, 2012 -- Mevion Medical Systems announced today that it has closed a $45 Million investment from ProQuest Investments and its existing investors, including Caxton Heath Life Sciences, Venrock and CHL Medical Partners. Mevion is the manufacturer of the MEVION S250 Proton Therapy System. The capital will be used to accelerate the manufacturing and worldwide deployment of the MEVION S250. Proton beam radiation therapy permits more precise dose targeting by complete proton absorption at predictable tissue depth, allowing the treatment of target volumes adjacent to critical structures without inadvertent dose to sensitive structures. The availability of proton therapy has remained very limited however, due to the enormous cost, large footprint, and technical complexity of traditional proton systems. Powered by a TriNiobium Core TM, the MEVION S250 significantly reduces the cost, size and complexity to levels similar to other modern X-ray radiation therapy devices, and brings accessibility, affordability and practicality to proton therapy. "We welcome the new endorsement by ProQuest Investments and the continuing support of our existing financial partners", said Joseph K. Jachinowski, Chief Executive Officer of Mevion Medical Systems. "With delivery of our first system complete and with two additional systems now under installation, this investment will support the growing demand for our innovative technology. We are also pleased to welcome Mr. Jay Moorin of ProQuest Investments onto the Mevion Medical Systems' Board of Directors," stated Jachinowski.