title: Nomogram for predicting incomplete cytoreduction in advanced ovarian cancer patients.
abstract: OBJECTIVE
  Accurately predicting cytoreducibility in advanced-ovarian cancer is needed to establish preoperative plans, consider neoadjuvant chemotherapy, and improve clinical trial protocols. We aimed to develop a positron-emission tomography/computed tomography-based nomogram for predicting incomplete cytoreduction in advanced-ovarian cancer patients.
  
  
  METHODS
  Between 2006 and 2012, 343 consecutive advanced-ovarian cancer patients underwent positron-emission tomography/computed tomography before primary cytoreduction: 240 and 103 patients were assigned to the model development or validation cohort, respectively. After reviewing the detailed surgical documentation, incomplete cytoreduction was defined as a remaining gross residual tumor. We evaluated each individual surgeon's surgical aggressiveness index (number of high-complex surgeries/total number of surgeries). Possible predictors, including surgical aggressiveness index and positron-emission tomography/computed tomography features, were analyzed using logistic regression modeling. A nomogram based on this model was developed and externally validated.
  
  
  RESULTS
  Complete cytoreduction was achieved in 120 patients (35%). Surgical aggressiveness index and five positron-emission tomography/computed tomography features were independent predictors of incomplete cytoreduction. Our nomogram predicted incomplete cytoreduction by incorporating these variables and demonstrated good predictive accuracy (concordance index = 0.881; 95% CI = 0.838-0.923). The predictive accuracy of our validation cohort was also good (concordance index = 0.881; 95% CI = 0.790-0.932) and the predicted probability was close to the actual observed outcome. Our model demonstrated good performance across surgeons with varying degrees of surgical aggressiveness.
  
  
  CONCLUSIONS
  We have developed and validated a nomogram for predicting incomplete cytoreduction in advanced-ovarian cancer patients which may help stratify patients for clinical trials, establish meticulous preoperative plans, and determine if neoadjuvant chemotherapy is warranted.
authors.affiliation: Department of Obstetrics and Gynecology, Konkuk University School of Medicine, Seoul, Republic of Korea.
authors.forename: Seung-Hyuk
authors.initials: SH
authors.lastname: Shim
authors.affiliation: Department of Obstetrics and Gynecology, Konkuk University School of Medicine, Seoul, Republic of Korea.
authors.forename: Sun Joo
authors.initials: SJ
authors.lastname: Lee
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea.
authors.forename: Seon-Ok
authors.initials: SO
authors.lastname: Kim
authors.affiliation: Department of Obstetrics and Gynecology, Konkuk University School of Medicine, Seoul, Republic of Korea.
authors.forename: Soo-Nyung
authors.initials: SN
authors.lastname: Kim
authors.affiliation: Department of Obstetrics and Gynecology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea. Electronic address: nastassja@naver.com.
authors.forename: Dae-Yeon
authors.initials: DY
authors.lastname: Kim
authors.affiliation: Department of Nuclear Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea.
authors.forename: Jong Jin
authors.initials: JJ
authors.lastname: Lee
authors.affiliation: Department of Obstetrics and Gynecology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea.
authors.forename: Jong-Hyeok
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Obstetrics and Gynecology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea.
authors.forename: Yong-Man
authors.initials: YM
authors.lastname: Kim
authors.affiliation: Department of Obstetrics and Gynecology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea.
authors.forename: Young-Tak
authors.initials: YT
authors.lastname: Kim
authors.affiliation: Department of Obstetrics and Gynecology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea.
authors.forename: Joo-Hyun
authors.initials: JH
authors.lastname: Nam
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000077216:Carcinoma, Ovarian Epithelial; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008875:Middle Aged; D064847:Multimodal Imaging; D009375:Neoplasms, Glandular and Epithelial / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D049451:Nomograms; D010051:Ovarian Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D049268:Positron-Emission Tomography; D011237:Predictive Value of Tests; D019275:Radiopharmaceuticals; D014057:Tomography, X-Ray Computed; D055815:Young Adult
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: Nomogram; Ovarian cancer; Positron emission tomography and computed tomography (PET/CT); Residual cancer; Surgical specialty