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

POROS: POsitioningRobotic for Oncology Systems

Meeting Abstract

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  • P. Samuel - Centre de Protonthérapie d'Orsay, Institut Curie, Orsay, France
  • R. Ferrand - Centre de Protonthérapie d'Orsay, Institut Curie, Orsay, France

PTCOG 48. Meeting of the Particle Therapy Co-Operative Group. Heidelberg, 28.09.-03.10.2009. Düsseldorf: German Medical Science GMS Publishing House; 2009. Doc09ptcog174

DOI: 10.3205/09ptcog174, URN: urn:nbn:de:0183-09ptcog1749

Published: September 24, 2009

© 2009 Samuel 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 project POROS (partnership between AS2I Company (leader), DOSIsoft Company, Centre de Protonthérapie de Orsay (C.P.O.) – Institut Curie, ISIR – Université Pierre et Marie Curie and CEA LIST) financed by the French research agency (ANR) has started on February 15th 2008 for 3 years. The purpose of this project is to develop a complete solution for patient positioning in protontherapy. This solution includes a compact robotic positioner, three external systems for patient registration and a global supervisor who manage the patient positioning process. The validation of the complete system will be conducted at ICPO for intra-cranial treatments by Protontherapy.

Material and methods: This project includes several systems:

  • A highly accurate medical robot, VULCAIN, with 6 degrees of freedom for the positioning of heavy loads. This robot is driven by an external controller and safety is guaranteed by redundancy sensors following EN ISO 13849-1 norms.
  • An infrared localizer NDI POLARIS® with 6 degrees of freedom combined with a control interface EAGLE able to perform the pre-positioning (inter fractions), static registration (intra fractions) and monitoring during irradiation.
  • A registration system ROTAPLUS based on X-ray imaging and implanted markers.
  • An anatomical registration system COMPARE based on X-ray imaging.

All of these components can be used according to a protocol established by the medical physicist for intra or inter fractions.

All these systems are connected, via a DICOM network, to a SUPERVISOR permitting the connection between patient data (medical workflow) and the various positioning systems. Each system (even other commercial products) can be plugged on a network switch as a "plug & play" computer device.

Results: A prototype of robotic positioner was built and tested by AS2I and CEA LIST teams. A calibration method has been developed to improve the absolute accuracy to ±0.5mm.

The alignment systems by EAGLE and ROTAPLUS are currently in use on patients in one of ICPO treatment rooms. EAGLE performs 100% success rate (on a head phantom Rando) for pre-positioning and 71.6% success rate for static registration. COMPARE is being validated on a head phantom Rando.

The SUPERVISOR is under development. The DICOM network between each project package is already working and man machine interface prototype has been designed.

Conclusion: The first tests of the alignment modules for the patient have shown it's possible to include such tools in the positioning process of the patient in radiotherapy. The first evaluation of the positioner by radiotherapy professionals shows that those performances (accuracy, embedded load) and its compactness answer to the current requirements.