Text and Data Mining valid from 2019-12-01
Received: 28 January 2019
Accepted: 11 December 2019
First Online: 18 December 2019
Ethics approval and consent to participate
: The study design was approved by the institutional review board of Samsung Medical Center (SMC IRB, Number: SMC 2018–11–148-001) and the requirement for informed consent was waived due to the retrospective nature of the study.
: Not applicable.
: The authors declare that they have no competing interests.