Introduction & Objectives
Data on the predictive value (i.e. identifying disease progression) of MRI after previous confirmatory biopsy in men on Active Surveillance (AS) are limited.
To compare outcomes of MRI + target biopsy (TBx) vs. TRUS-guided systematic biopsy (SBx) at 2nd surveillance biopsy in men on AS and assess whether MRI can selectively identify patients with disease progression (i.e. Gleason score upgrading) to avoid biopsy procedures in those with stable disease.
Material & Methods
A total of 30 men on AS received multiparametric MRI in our academic institute at 2nd surveillance biopsy after previous confirmatory biopsy.TBx of suspicious lesions (PI-RADS >= 3) was performed using the MRI-US fusion technique. 62 men (all participants in the PRIAS study; www.prias-project.org)
who received 2nd surveillance SBx served as a control group. Outcomes of TBx and SBx were compared to assess the upgrading rates and potentially
saved biopsy procedures when biopsying only those men with a positive MRI. Cox proportional hazard regression analysis was performed to assess whether receiving MRI was an independent predictor for upgrading, after correction for age and PSA.
|MRI + TBx||SBx|
|Age (years), median (IQR)||67.5 (62.1 – 72.0)||68.6 (63.5 – 74.3)|
|Time between diagnosis and biopsy (years), |
|3.8 (2.8 – 5.6)||3.9 (2.5 – 4.2)|
|PSA at diagnosis (ng/ml), median (IQR)||7.2 (4.8 – 9.3)||4.5 (3.0 – 6.1)|
|PSA at biopsy (ng/ml), median (IQR)||10.3 (5.9 – 15.0)||5.2 (3.0 – 8.5)|
|Outcome 2nd surveillance biopsy|
|MRI not suspicious for PCa||8 (27%)||/|
|No PCa in biopsy||6 (20%)||24 (39%)|
|Gleason score = 3+3 PCa in biopsy||8 (27%)||33 (53%)|
|Gleason score >= 3+4 PCa in biopsy||8 (27%)||5 (8%)|
|Total nr. of patients||30 (100%)||62 (100%)|
MRI+ TBx resulted in more Gleason score upgrading than SBx (27% vs. 8%). However, men who received MRI instead of SBx had higher PSA-levels both at diagnosis and at 2nd surveillance biopsy. After correction for the PSA-levels, receiving MRI was no independent predictor for upgrading: HR = 1.39 (95% CI 0.16 – 3.3), p = 0.672. Although the PSA-levels and high-grade (Gleason score >= 3+4) PCa rate were higher in the MRI group, 27% of these men had a negative MRI and thus did not receive TBx.
A larger sample size and follow-up data are needed to confirm these preliminary results: Performing a MRI at 2nd surveillance biopsy could save app. 30% of prostate biopsy procedures without compromising the identification of disease progression.