[Necessity analysis of bone scan in patients with newly diagnosed prostate cancer]

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.

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.

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%.

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.