1) Division of Surgery, Fukushima Medical University, Fukushima, Japan
2) Department of Healthcare Quality Assessment, Postgraduate School of Medicine, University of Tokyo, Tokyo, Japan
3) Department of Surgical Oncology, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan

Mitsukazu Gotoh¹⁾, Hiroaki Miyata²⁾, Kenichi Sugihara³⁾