Validation of a bone scan positivity risk table in non-metastatic castration-resistant prostate cancer.


Journal Article

To test the external validity of a previously developed risk table, designed to predict the probability of a positive bone scan among men with non-metastatic (M0) castration-resistant prostate cancer (CRPC), in a separate cohort.We retrospectively analysed 429 bone scans of 281 patients with CRPC, with no known previous metastases, treated at three Veterans Affairs Medical Centers. We assessed the predictors of a positive scan using generalized estimating equations. Area under the curve (AUC), calibration plots and decision-curve analysis were used to assess the performance of our previous model to predict a positive scan in the current data.A total of 113 scans (26%) were positive. On multivariable analysis, the only significant predictors of a positive scan were log-transformed prostate-specific antigen (PSA): hazard ratio (HR) 2.13; 95% confidence interval (CI) 1.71-2.66 (P < 0.001) and log-transformed PSA doubling time (PSADT): HR 0.53; 95% CI 0.41-0.68 (P < 0.001). Among men with a PSA level <5 ng/mL, the rate of positive scans was 5%. The previously developed risk table had an AUC of 0.735 to predict positive bone scan with excellent calibration, and provided additional net benefit in the decision-curve analysis.We have validated our previously developed table to predict the risk of a positive bone scan among men with M0/Mx CRPC. Use of this risk table may allow better tailoring of patients' scanning to identify metastases early, while minimizing over-imaging. Regardless of PSADT, positive bone scans were rare in men with a PSA <5 ng/mL.

Full Text

Duke Authors

Cited Authors

  • Freedland, SJ; Howard, LE; Hanyok, BT; Kadiyala, VK; Kuang, JY; Whitney, CA; Wilks, FR; Kane, CJ; Terris, MK; Amling, CL; Cooperberg, MR; Aronson, WJ; Moreira, DM

Published Date

  • October 2016

Published In

Volume / Issue

  • 118 / 4

Start / End Page

  • 570 - 577

PubMed ID

  • 26762961

Pubmed Central ID

  • 26762961

Electronic International Standard Serial Number (EISSN)

  • 1464-410X

International Standard Serial Number (ISSN)

  • 1464-4096

Digital Object Identifier (DOI)

  • 10.1111/bju.13405


  • eng