Received: 7 December 2020
Accepted: 4 May 2021
First Online: 27 May 2021
: This study was reviewed and approved by the Institutional Review Board of Severance Hospital, Yonsei University College of Medicine (No. 3-2020-0457). Consent to participate for this study was waived per the approval of the Institutional Review Board of Severance Hospital, Yonsei University College of Medicine, since this was a retrospective study. All methods were performed in accordance with the ethical standards of the institutional review board of ethics committee and national research committee with the Helsinki Declaration of 1964 and later versions.
: Not applicable.
: The authors declare no competing interests.