1. Accuray Incorporated
2. Advanced Oncotherapy PLC
3. Hitachi Ltd.
4. Ion Beam Applications SA
5. Koninklijke Philips N.V.
6. Mevion Medical Systems Inc.
7. Mitsubishi Electric Corporation
8. Optivus Proton Therapy Inc.
9. ProNova Solutions
LLC
10. ProTon International
11. Protonic Medical Systems Private Limited
12. Provision Healthcare
LLC
13. PTW Freiburg GmbH
14. Radiological Society of North America
Inc
15. RaySearch Laboratories AB
16. Sumitomo Heavy Industries Ltd.
17. Thermo Fisher Scientific Inc.