EURURO Vol. 72 No. 2

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The simplest MRI-targeted biopsy strategy is the
cognitive approach, which directs visually targeted samples
to the suspicious ROI highlighted on mpMRI. Three RCTs
have compared a first biopsy pathway based on mpMRI to
12-core SB alone, producing conflicting results
The first two studies concluded that the PCa DR
was higher in the mpMRI group . In the most recent
RCT, the authors reported that the mpMRI group had
comparable DRs of PCa and csPCa compared with the
control group .
MRI/TRUS fusion software-based TB represents the most
accurate and practical TB strategy . One RCT that used
fusion biopsy in a diagnostic pathway based on mpMRI was
published . In the mpMRI group, two-core fusion biopsy
of mpMRI–suspected lesions and 12-core SB were per-
formed. No significant differences were detected between
the mpMRI and control groups (12-core SB) in either the PCa
DR (59.0% vs 54.0%, respectively) or the csPCa DR (44.0% vs
49.0%, respectively). In contrast, some nonrandomized
studies comparing MRI-targeted biopsy and SB in biopsy-
naı¨ve men have concluded that the approach using mpMRI
and subsequent fusion biopsy limited overdetection of
clinically insignificant PCa while providing greater detec-
tion of csPCa than SB alone
To our knowledge, this study was the first RCT
comparing PCa DRs between a diagnostic pathway, based
on mpMRI and subsequent MRI/TRUS fusion software-
guided TB alone, with the standard pathway, based on SB, in
a cohort of biopsy-naı¨ve men.
The first report of our RCT seemed to confirm the
potential role of mpMRI as a first-line technique in the
diagnostic pathway of biopsy-naı¨ve patients with suspected
PCa, according to our inclusion criteria.
PCa was diagnosed in 50.5% of patients in the mpMRI
group, with 87.0% of cases being clinically significant. These
data significantly outperformed the results of the standard
pathway. In this group, the overall DR of PCa was 29.5%,
similar to the results of previously published series of SB in
biopsy-naı¨ve patients . We emphasize that the present
study was restricted to patients with PSA levels 15 ng/ml
and negative DRE results only.
The differences in PCa DRs between the arms of the study
were greater than those found in earlier RCTs perhaps
owing to the different protocols used (cognitive biopsy ,
two-core fusion biopsy ) and the patient selection
criteria.
When stratifying the population in terms of the
approach to biopsy, we found that TB in arm A MRI+ had
the best results in terms of the overall DR of PCa (60.5%) and
the DR of csPCa (93.9%). The analysis in the different
subgroups might have been affected by the underpowered
sample size.
The usefulness of the PI-RADS classification was
emphasized by our findings: a significantly higher DR
was found in terms of overall detection of PCa and csPCa in
lesions with PI-RADS scores of 4 and 5 than in those with a
PI-RADS score of 3. The results in suggested
that lesions with a PI-RADS score of 3 might not receive
biopsy, although they were all diagnosed as csPCa after
biopsy.
The pathologic results confirmed the superiority of the
mpMRI pathway in terms of the quality of biopsy samples.
Fewer biopsy samples per patient were necessary in arm A
than in arm B. The median total, maximum CCL, and
maximum CCI were significantly higher in arm A than in
arm B.
Table 4 – Histopathologic characteristics of the study population
Arm A, mpMRI group Arm B, control group p value
Group size, n 107 105
PCa, no. (%) 54 (50.5) 31 (29.5) 0.002
Biopsy GS, no. (%)
6 10 (18.5) 17 (54.8) 0.002
7 38 (70.4) 11 (35.5)
8 5 (9.3) 2 (6.5)
>8 1 (1.9) 1 (3.2)
Total CCL, mm 16 (8–31) 5 (2–20) 0.005
Maximum CCL, mm 7 (5–9) 4 (2–8) 0.013
Maximum CCI, % 60 (33–77) 25 (14–67) 0.010
TB SB, arm A SB, arm B p value
Group size, n 81 26 105
PCa, no. (%) 49 (60.5) 5 (19.2) 31 (29.5) <0.001
Biopsy GS, no. (%)
6 5 (10.2) 5 (100) 17 (54.8)
7 38 (77.6) 0 (0) 11 (35.5) <0.001
8 5 (10.2) 0 (0) 2 (6.5)
>8 1 (2.0) 0 (0) 1 (3.2)
Total CCL, mm 18 (10–32) 3 (2–3) 5 (2–20) 0.048
Maximum CCL, mm 8 (6–10) 2 (1–3) 4 (2–8) 0.064
Maximum CCI, % 67 (33–80) 10 (9–25) 25 (14–67) 0.062
CCI = cancer core invasion; CCL = cancer core length; GS = Gleason score; mpMRI = multiparametric magnetic resonance imaging; SB = standard biopsy;
TB = targeted biopsy.
Data for continuous variables are presented as the median (interquartile range).
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