Received: 1 December 2020
Accepted: 9 March 2021
First Online: 17 March 2021
: This study protocol complied with the Declaration of Helsinki and was approved by the ethics committee at Fukushima Medical University (acceptance no. 2069). All patients received an explanation of the procedures and possible risks of this study and gave their written, informed consent to participate in this study.
: Not applicable.
: The authors declare that they have no competing interest.