ABOUT MEVION MEDICAL SYSTEMSMevion Medical Systems, Inc. (formerly Still River Systems, Inc.) is a radiation therapy company dedicated to advancing the treatment of cancer. As the pioneering developer of modern proton therapy systems, Mevion provides innovative, safe, and effective solutions by transforming advances in medical technology and science into practical clinical reality.Mevion's flagship product, the MEVION S250 Proton Therapy System, is designed to preserve all of the treatment benefits of traditional proton therapy systems while removing the obstacles of size, cost, and complexity. Realizing this vision, Mevion has forever changed the economics and accessibility of proton therapy worldwide. Founded in 2004, Mevion is a privately held company headquartered in the Boston metropolitan area with international offices in the United Kingdom and Japan. The MEVION S250 Proton Therapy System is pending United States Food and Drug Administration 510(k) clearance. Visit us at: www.mevion.com # # # Contact:Melanie M. MillerMarketing & Communications CoordinatorMevion Medical SystemsE: email@example.comP: 978.540.1551 About AMS American Shared Hospital Services provides turnkey technology solutions for advanced radiosurgical and radiation therapy services. AMS is the world leader in providing Gamma Knife radiosurgery equipment, a non-invasive treatment for malignant and benign brain tumors, vascular malformations and trigeminal neuralgia (facial pain). The Company also offers the latest IGRT and IMRT systems, as well as its proprietary Operating Room for the 21st Century ® concept. Through its preferred stock investment in Mevion Medical Systems, Inc., formerly Still River Systems, AMS also plans to complement these services with the MEVION S250 proton beam radiation therapy (PBRT) system, which has not yet been approved by the FDA. Safe Harbor Statement This press release may be deemed to contain certain forward-looking statements with respect to the financial condition, results of operations and future plans of American Shared Hospital Services, which involve risks and uncertainties including, but not limited to, the risks of the Gamma Knife and radiation therapy businesses, the risks of developing The Operating Room for the 21st Century program, and the risks of investing in a development-stage company, Mevion Medical Systems, Inc., without a proven product. Further information on potential factors that could affect the financial condition, results of operations and future plans of American Shared Hospital Services is included in the filings of the Company with the Securities and Exchange Commission, including the Company's Annual Report on Form 10-K for the year ended December 31, 2010, the Quarterly Report on Form 10-Q for the quarter ended March 31, 2011, Form 10-Q and 10-Q/A for the quarter ended June 30, 2011, and Form 10-Q for the quarter ended September 30, 2011, and the definitive Proxy Statement for the Annual Meeting of Shareholders held on June 9, 2011.