Article History
Received: 2 November 2019
Accepted: 17 February 2020
First Online: 20 February 2020
Ethics approval and consent to participate
: This retrospective cohort study was approved by the institutional review board (IRB) of the Seoul National University Bundang Hospital (SNUBH) (Approval number: B-1809-495-102, approval date: September 7, 2018). Considering the retrospective nature of the study, in which the medical records of patients who had already completed treatment were analyzed, the requirement for obtaining informed consent was waived by the IRB.
: Not applicable.
: The authors declare that they have no competing interests.