title: Learning curve analysis of laparoscopic radical hysterectomy for gynecologic oncologists without open counterpart experience.
abstract: OBJECTIVE
  To evaluate the learning curve of laparoscopic radical hysterectomy (LRH) for gynecologic oncologists who underwent residency- and fellowship-training on laparoscopic surgery without previous experience in performing abdominal radical hysterectomy (ARH).
  
  
  METHODS
  We retrospectively reviewed 84 patients with FIGO (International Federation of Gynecology and Obstetrics) stage IB cervical cancer who underwent LRH (Piver type III) between April 2006 and March 2014. The patients were divided into two groups (surgeon A group, 42 patients; surgeon B group, 42 patients) according to the surgeon with or without ARH experience. Clinico-pathologic data were analyzed between the 2 groups. Operating times were analyzed using the cumulative sum technique.
  
  
  RESULTS
  The operating time in surgeon A started at 5 to 10 standard deviations of mean operating time and afterward steeply decreased with operative experience (Pearson correlation coefficient=-0.508, P=0.001). Surgeon B, however, showed a gentle slope of learning curve within 2 standard deviations of mean operating time (Pearson correlation coefficient=-0.225, P=0.152). Approximately 18 cases for both surgeons were required to achieve surgical proficiency for LRH. Multivariate analysis showed that tumor size (>4 cm) was significantly associated with increased operating time (P=0.027; odds ratio, 4.667; 95% confidence interval, 1.187 to 18.352).
  
  
  CONCLUSIONS
  After completing the residency- and fellowship-training course on gynecologic laparoscopy, gynecologic oncologists, even without ARH experience, might reach an acceptable level of surgical proficiency in LRH after approximately 20 cases and showed a gentle slope of learning curve, taking less effort to initially perform LRH.
authors.affiliation: Gynecologic Cancer Center, Ajou University School of Medicine, Suwon, Korea. ; Department of Obstetrics and Gynecology, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Tae-Wook
authors.initials: TW
authors.lastname: Kong
authors.affiliation: Gynecologic Cancer Center, Ajou University School of Medicine, Suwon, Korea. ; Department of Obstetrics and Gynecology, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Suk-Joon
authors.initials: SJ
authors.lastname: Chang
authors.affiliation: Gynecologic Cancer Center, Ajou University School of Medicine, Suwon, Korea. ; Department of Obstetrics and Gynecology, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Jiheum
authors.initials: J
authors.lastname: Paek
authors.affiliation: Department of Obstetrics and Gynecology, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Hyogyeong
authors.initials: H
authors.lastname: Park
authors.affiliation: Department of Obstetrics and Gynecology, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Seong Woo
authors.initials: SW
authors.lastname: Kang
authors.affiliation: Gynecologic Cancer Center, Ajou University School of Medicine, Suwon, Korea. ; Department of Obstetrics and Gynecology, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Hee-Sug
authors.initials: HS
authors.lastname: Ryu
keywords: Cumulative sum; Laparoscopic radical hysterectomy; Learning curve