title: [Necessity analysis of bone scan in patients with newly diagnosed prostate cancer].
abstract: OBJECTIVE
  To construct a classification and regression tree (CART) to predict the occurrences of bone metastases in patients with newly diagnosed prostate cancer so as to reduce unnecessary bone scans.
  
  
  METHODS
  CART analyses were performed in 501 subjects from 2005 to 2011 of Fudan University Shanghai Cancer Center to establish Fudan CART model and externally validate Briganti's CART model. The both models were compared with regards to the area under the curve (AUC) and their clinical values.
  
  
  RESULTS
  The rate of bone metastasis was 27.5% (138/501). The predictive accuracy of Fudan CART model, Briganti's CART model and skeleton-related events (SRE) model was 0.813, 0.691 and 0.645 respectively. There were statistically significant differences (P < 0.05). Fudan CART model had a lower missed diagnosis and an over-examination rate of bone scan within the probability threshold (Pt) range of 24.2% to 36.8%.
  
  
  CONCLUSIONS
  With a higher predictive value, Fudan CART model may be employed to reduce the unnecessary bone scans for Chinese patients with newly diagnosed prostate cancer.
authors.affiliation: Department of Urology, Fudan University Shanghai Cancer Center, Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, China.
authors.forename: Jia-quan
authors.initials: JQ
authors.lastname: Zhou
authors.forename: Yao
authors.initials: Y
authors.lastname: Zhu
authors.forename: Xu-dong
authors.initials: XD
authors.lastname: Yao
authors.forename: Shi-lin
authors.initials: SL
authors.lastname: Zhang
authors.forename: Bo
authors.initials: B
authors.lastname: Dai
authors.forename: Hai-liang
authors.initials: HL
authors.lastname: Zhang
authors.forename: Ding-wei
authors.initials: DW
authors.lastname: Ye
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001859:Bone Neoplasms / Q000000981:diagnostic imaging / Q000556:secondary; D001842:Bone and Bones / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D011237:Predictive Value of Tests; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D011877:Radionuclide Imaging; D012044:Regression Analysis