Received: 14 December 2017
Accepted: 31 May 2019
First Online: 14 June 2019
Ethics approval and consent to participate
: The study was approved by the institutional review board and ethics committee of the National Cancer Institute.Bratislava, Slovakia and a waiver of consent was granted.
: A written consent from patient’s mother was obtained. A copy of written consent is available for the journal.
: The authors declare that they have no competing interests.