Received: 16 October 2017
Accepted: 31 January 2018
First Online: 21 February 2018
Ethics approval and consent to participate
: This study was submitted to the regional ethics committee of Hauts-de-France, France (No 2016/70). The protocol was approved and considered an observational study that does not amend current diagnostic or therapeutic strategies. Informed consent was waived because of the retrospective nature of the study.
: Not applicable.
: The authors declare that they have no competing interests.
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