Comparison of Rotterdam and Barcelona Magnetic Resonance Imaging Risk Calculators for Predicting Clinically Significant Prostate Cancer

Abstract

Background: Magnetic resonance imaging (MRI)-based risk calculators (MRI-RCs) individualise the likelihood of clinically significant prostate cancer (csPCa) and improve candidate selection for prostate biopsy beyond the Prostate Imaging Reporting and Data System (PI-RADS).

Objective: To compare the Barcelona (BCN) and Rotterdam (ROT) MRI-RCs in an entire population and according to the PI-RADS categories.

Design setting and participants: A prospective comparison of BCN- and ROT-RC in 946 men with suspected prostate cancer in whom systematic biopsy was performed, as well as target biopsies of PI-RADS ≥3 lesions.

Outcome measurements and statistical analysis: Saved biopsies and undetected csPCa (grade group ≥2) were determined.

Results and limitations: The csPCa detection was 40.8%. The median risks of csPCa from BCN- and ROT-RC were, respectively, 67.1% and 25% in men with csPCa, whereas 10.5% and 3% in those without csPCa (p < 0.001). The areas under the curve were 0.856 and 0.844, respectively (p = 0.116). BCN-RC showed a higher net benefit and clinical utility over ROT-RC. Using appropriate thresholds, respectively, 75% and 80% of biopsies were needed to identify 50% of csPCa detected in men with PI-RADS <3, whereas 35% and 21% of biopsies were saved, missing 10% of csPCa detected in men with PI-RADS 3. BCN-RC saved 15% of biopsies, missing 2% of csPCa in men with PI-RADS 4, whereas ROT-RC saved 10%, missing 6%. No RC saved biopsies without missing csPCa in men with PI-RADS 5.

Conclusions: ROT-RC provided a lower and narrower range of csPCa probabilities than BCN-RC. BCN-RC showed a net benefit over ROT-RC in the entire population. However, BCN-RC was useful in men with PI-RADS 3 and 4, whereas ROT-RC was useful only in those with PI-RADS 3. No RC seemed to be helpful in men with negative MRI and PI-RADS 5.

Patient summary: Barcelona risk calculator was more helpful than Rotterdam risk calculator to select candidates for prostate biopsy.

Keywords: Clinically significant; Early detection; Magnetic resonance imaging; Predictive model; Prostate cancer; Risk calculator.

Fig. 1

Violin plots of csPCa likelihoods of men without and with csPCa estimated with ROT MRI-RC and BCN MRI-RC. BCN = Barcelona; csPCa = clinically significant prostate cancer; MRI-RC = magnetic resonance imaging–based risk calculator; ROT = Rotterdam.

Fig. 2

Calibration curves of (A) ROT MRI-RC and (B) BCN MRI-RC. BCN = Barcelona; MRI-RC = magnetic resonance imaging–based risk calculator; ROT = Rotterdam.

Fig. 3

(A) Discrimination ability of csPCa of BCN MRI-RC and ROT MRI-RC presented with ROC curves, (B) net benefit of BCN MRI-RC and ROT MRI-RC over biopsying all men presented by DCAs, and (C) clinical utility of BCN MRI-RC and ROT MRI-RC showing the percentage of avoided biopsies and missed csPCa according to the threshold probability of csPCa by CUCs. BCN = Barcelona; csPCa = clinically significant prostate cancer; CUC = clinical utility curve; DCA = decision curve analysis; MRI-RC = magnetic resonance imaging–based risk calculator; ROT = Rotterdam.

Fig. 4

Violin plots of csPCa likelihoods, estimated from (A) ROT MRI-RC and (B) BCN MRI-RC, in men without and with csPCa according to the PI-RADS categories. BCN = Barcelona; csPCa = clinically significant prostate cancer; MRI-RC = magnetic resonance imaging–based risk calculator; PI-RADS = Prostate Imaging Reporting and Data System; ROT = Rotterdam.

Fig. 5

Discrimination ability presented by ROC curves, net benefit presented by DCAs, and clinical utility presented by CUCs, of BCN MRI-RC and ROT MRI-RC according to the PI-RADS categories: (A–C) PI-RADS <3, (D–F) PI-RADS 3, (G–I) PI-RADS 4, and (J–L) PI-RADS 5. BCN = Barcelona; csPCa = clinically significant prostate cancer; CUC = clinical utility curve; MRI-RC = magnetic resonance imaging–based risk calculator; PI-RADS = Prostate Imaging Reporting and Data System; ROT = Rotterdam.