gms | German Medical Science

48th Meeting of the Particle Therapy Co-Operative Group

Particle Therapy Co-Operative Group (PTCOG)

28.09. - 03.10.2009, Heidelberg

Common control system software for the advanced scanning techniques of PSIs Gantry 2 and the highly efficient passive scattering technique of Optis 2

Meeting Abstract

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  • Chr. Bula - Center for Proton Therapy, Paul Scherrer Institut, Villigen PSI, Switzerland
  • S. Rees - Center for Proton Therapy, Paul Scherrer Institut, Villigen PSI, Switzerland
  • A. Mayor - Center for Proton Therapy, Paul Scherrer Institut, Villigen PSI, Switzerland

PTCOG 48. Meeting of the Particle Therapy Co-Operative Group. Heidelberg, 28.09.-03.10.2009. Düsseldorf: German Medical Science GMS Publishing House; 2009. Doc09ptcog026

doi: 10.3205/09ptcog026, urn:nbn:de:0183-09ptcog0265

Published: September 24, 2009

© 2009 Bula et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.



Background: The PSI Center for Proton Therapy is currently commissioning two new areas for cancer treatment with proton beams. In the Optis 2 area, a highly efficient passive scattering technique is used to treat ocular melanomas. At Gantry 2 advanced scanning techniques are developed and will be applied for the treatment of moving tumors. Despite the apparent differences between the two stations, we choose a common approach in the realization of the control systems software.

Materials and methods: The control systems use PowerPC single board computers running the real-time operating system VxWorks. The software is developed using object-oriented methods and C++ as the programming language, and is logically divided in three layers. The Foundation layer provides the basic services and utilities needed by the software. The Framework layer implements control system related features which are common to both Gantry 2 and Optis 2. The project specific tasks are handled in the third layer. By introducing a dynamic system configuration service, we maximized the functionality in the first two layers.

Results: The Optis 2 control system is complete and ready for patient treatment. The Gantry 2 system is well advanced and routinely used for beam line and gantry commissioning. The common software framework covers approximately 80% of the control system functionality. The architecture proved flexible enough to accommodate all necessary project-specific extensions.

Conclusions: We realized the control system for two diverse treatment areas by employing a common software framework. Compared to independent developments, this approach reduced both costs and time and distributed critical know-how among more people. We plan to employ the same framework for a rebuild of the control system software of Gantry 1, the first treatment area at PSI operational since 1996.