Email updates

Keep up to date with the latest news and content from Radiation Oncology and BioMed Central.

Open Access Open Badges Research

Accuracy of robotic patient positioners used in ion beam therapy

Olaf Nairz13*, Marcus Winter1, Peter Heeg1 and Oliver Jäkel12

Author Affiliations

1 Heidelberger Ionenstrahl-Therapiezentrum, Im Neuenheimer Feld 450, Heidelberg 69120, Germany

2 Department of Radiation Oncology and Radiotherapy, University Hospital Heidelberg, Im Neuenheimer Feld 400, Heidelberg 69120, Germany

3 Paracelsus Medical University Salzburg, Strubergasse 21, Salzburg 5020, Austria

For all author emails, please log on.

Radiation Oncology 2013, 8:124  doi:10.1186/1748-717X-8-124

Published: 21 May 2013



In this study we investigate the accuracy of industrial six axes robots employed for patient positioning at the Heidelberg Ion Beam Therapy Center.


In total 1018 patient setups were monitored with a laser tracker and subsequently analyzed. The measurements were performed in the two rooms with a fixed horizontal beam line. Both, the 3d translational errors and the rotational errors around the three table axes were determined.


For the first room the 3d error was smaller than 0.72 mm in 95 percent of all setups. The standard deviation of the rotational errors was at most 0.026° for all axes. For the second room Siemens implemented an improved approach strategy to the final couch positions. The 95 percent quantile of the 3d error could in this room be reduced to 0.53 mm; the standard deviation of the rotational errors was also at most 0.026°.


Robots are very flexible tools for patient positioning in six degrees of freedom. This study proved that the robots are able to achieve clinically acceptable accuracy in real patient setups, too.

Robotic patient positioning; 6 degrees of freedom; Accuracy; Ion beam therapy; High precision radiation therapy