RayStation is RaySearch's proprietary treatment planning system. The system incoporates all of RaySearch's technologies and is based on RaySearch’s well proven and world leading optimization application tools that have been in operation for almost ten years. The core of the system is the ORBIT software framework which is currently used by some 2,000 clinics all over the world for optimization of IMRT, VMAT and 3DCRT. The system also contains functionality that is unique in many aspects. For example, RayStation has been designed for 4D adaptive radiation therapy as a built-in generic feature and it incorporates the latest techniques for proton therapy. It also contains tools for multi-criteria optimization enabling a much more intuitive treatment planning process. The modular and open design of RayStation makes it possible to find the perfect combinations of capabilities without getting stuck with time-consuming transfers between systems. While RayStation does provide best-in-class solutions for every step in the planning process, it is still possible to retain legacy systems for particular steps thanks to the connectivity of RayStation. The first RayStation user is one of the world’s most advanced proton therapy clinics – Westdeutsches Protonentherapiezentrum Essen (WPE) in Germany. The WPE facility is designed around the adaptive therapy concept with infrastructure for daily patient imaging and automated transportation of immobilized patients. They selected RayStation for its unique ability to create robust and adaptive plans for treatment of moving tumors, such as lung sarcoma, with proton PBS.