Funding for this research was provided by:
National Research Foundation of Korea (2018R1D1A1A02049236)
Bio & Medical Technology Development Program of the NRF (NRF-2016M3A9D5A01952414)
NRF Grant funded by the Korean Governmen (2016R1A5A2008630)
Yonsei University College of Medicine (6-2018-0167)
Received: 23 May 2019
Accepted: 17 February 2020
First Online: 24 February 2020
Ethics approval and consent to participate
: This retrospective study was reviewed and approved by the Institutional Review Board of Severance Hospital, South Korea (4–2018-0861). Informed consent was waived by the institutional review board because of the retrospective study design. This study was also performed according to the Declaration of Helsinki.
: Not applicable.
: The authors declare that they have no competing interests.