Funding for this research was provided by:
Elekta
Elekta
Article History
Received: 17 October 2017
Accepted: 19 February 2018
First Online: 9 March 2018
Compliance with ethical guidelines
:
: U. Ganswindt and C. Belka have a research cooperation with Elekta AB, Stockholm, Sweden. H. Ballhausen and M. Li declare that they have no competing interests.
: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. For this type of study formal consent is not required. This article does not contain any studies with animals performed by any of the authors.