Proton Beam Treatment is used for cancer treatment but also may be useful for acoustic neuroma or vestibular shwannoma treatment. The following article offers some details about the upcoming expansion of the Proton Centers. Hope this helps:
http://www.itnonline.com/article/27-us-proton-therapy-centers-expected-2017March 14, 2014 — Research and Markets have announced the addition of the "US Proton Therapy Outlook 2017."
Physicians, in the face of an alarmingly rising incidences of cancer and limited treatment options are being forced to look for treatments beyond the conventional ones. In such a scenario, proton therapy is being projected as the Rolls Royce of radiation oncology. Unfortunately, access to proton therapy is limited for many patients due to the low number of proton therapy centers. Hence, many research institutes and hospitals are now investing in proton therapy to make it more accessible to patients.
According to the U.S. Proton Therapy Outlook 2017, the United States will be home to almost 27 such centers by 2017, a number, which is almost double the current figure. Consequentially, the market will breach the billion dollar mark to attain revenue of $1.17 Billion by 2017. The following 65 pages report provides an insight into the cancer demographics of U.S. and the various possible causes for a high incidence there. The document covers the historical trend (2008-2013) of cancer incidences, deaths and prevalence along with statewide and site-wide cancer incidences in the country.
The research covers the key companies developing or with already commissioned systems, including Hitachi, IBA, Mevion Medical Systems and Varian.
It describes the various types of radiation therapies, which can be used to treat cancer, as well as their disadvantages. Special attention has been given on proton therapy and its benefits that make it stand out amidst the conventional treatment options. The study dedicates a complete chapter on the various components of any proton therapy center and covers issues related to accelerators, delivery, transportation, planning and positioning systems to human resources required to setup a center.
As for the market, the report provides the statewide distribution of proton therapy centers in the U.S. A thorough analysis has been done on the existing and upcoming proton therapy centers to measure the market size and its future condition. The report further provides the state-wise statistics of potential patients for proton therapy and the latter's current market penetration. This is then followed by a section dedicated to market opportunity assessment, which would help service providers and vendors to extract benefits from the largely untapped but lucrative market.
For more information:
www.reseasrchandmarkets.com 
ALSO dear ANA forum members here are a couple of studies:
http://www.ncbi.nlm.nih.gov/pubmed/?term=mri+after+proton+beam+treatment+of+vesitibular+schwanoma Int J Radiat Oncol Biol Phys. 2002 Sep 1;54(1):35-44.
Proton beam stereotactic radiosurgery of vestibular schwannomas.
Harsh GR1, Thornton AF, Chapman PH, Bussiere MR, Rabinov JD, Loeffler JS.
“…Thus, 97% of tumors required no additional treatment….”
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Proton beam radiosurgery for vestibular schwannoma: tumor control and cranial nerve toxicity.
Weber DC1, Chan AW, Bussiere MR, Harsh GR 4th, Ancukiewicz M, Barker FG 2nd, Thornton AT, Martuza RL, Nadol JB Jr, Chapman PH, Loeffler JS. Neurosurgery. 2003 Sep;53(3):577-86; discussion 586-8.
“…The actuarial 5-year cumulative radiological reduction rate was 94.7% (95% CI, 81.2-98.3%)….”
