Article History
Received: 8 January 2019
Accepted: 21 February 2019
First Online: 27 February 2019
Compliance with ethical standards
:
: None of the authors have a personal conflict of interest to declare.
: All procedures performed in this study 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. Because of the retrospective study design, formal consent was not required. The study was approved by the Ethics Commission at the Radboud university medical center Nijmegen, The Netherlands. METC CMO Regio Arnhem-Nijmegen (Reg.nr. 2O14-1437) d.d.29/1/2015.