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results. Among those with negative MRI-ultrasound fusion
biopsy results, 7 (9%) had major upgrading on systematic
biopsy. Characteristics did not differ significantly between
patients with any upgrading on MRI-ultrasound fusion
biopsy versus on systematic biopsy (Supplementary
Table 2).
MRI-ultrasound fusion biopsy alone missed 39 patients
with GS 3 + 4 detected by systematic biopsy, but it
detected an additional 34 GS 3 + 4 cancers not seen by
systematic sampling. Among the 77 patients with negative
MRI-ultrasound fusion cores, systematic biopsy yielded GS
3 + 3 in 42 (55%), GS 3 + 4 in 5 (6%), and GS 4 + 3 for 7 (9%).
Among 58 patients with GS 3 + 3 in MRI-ultrasound fusion
cores, systematic biopsy revealed GS 3 + 4 in 15 (26%) and
3 (5%) with GS 4 + 3 disease
( Table 3).
In a logistic regression analysis of 130 men with
systematic GS 3 + 3, older age was independently
associated with likelihood of any upgrading from systematic
biopsy to concurrent MRI-ultrasound fusion biopsy (odds
ratio [OR]: 1.10; 95% confidence interval [CI], 1.01–1.20;
p
= 0.03), adjusting for PSA level, prostate volume, number of
previous biopsy sessions, presence of a hypoechoic lesion on
TRUS, cores sampled at systematic biopsy and at MRI-
ultrasound fusion biopsy, and months from mpMRI to MRI-
ultrasound fusion biopsy
( Table 4 ). The AUC was 0.74. No
variable was independently associated with likelihood of
major upgrading (AUC 0.81) in a similarly adjustedmodel for
182 men with systematic GS 3 + 4
( Table 4 ). Suspicion
scores were high (4/5) for all but 2 patients with any
upgrading and all with major upgrading.
4.
Discussion
We examined the role of MRI-ultrasound fusion biopsy
during AS for 207 men with low- or intermediate-risk PCa.
In all, MRI-ultrasound fusion biopsy resulted in GS
upgrading undetected with concurrent systematic biopsy
for an additional 14% of men, whereas 24% of men
experienced upgrade from prior biopsy with systematic
sampling alone. In 9% of patients, MRI-ultrasound fusion
cores were negative but systematic biopsy detected
GS 4 + 3. MRI-ultrasound fusion estimates for maximum
Table 3 – Number of cases graded at systematic biopsy and at concurrent magnetic resonance imaging–ultrasound fusion biopsy for
207 men with active surveillance for prostate cancer management
Concurrent MRI-ultrasound fusion biopsy GS
Systematic biopsy GS
Neg
3 + 3
3 + 4
4 + 3
4 + 4
4 + 5
5 + 4
Total
Neg
23
4
3
-
1
-
-
31
3 + 3
42
36
20
1
-
1
-
100
3 + 4
5
15
25
4
1
1
-
51
4 + 3
5
2
6
4
1
-
18
4 + 4
2
1
-
1
0
-
-
4
4 + 5
-
-
-
1
1
0
1
3
Total
77
58
54
11
3
3
1
207
Concurrent MRI-ultrasound fusion biopsy summary
Systematic biopsy summary
GS
<
3 + 4
3 + 4
>
3 + 4
McNemar’s statistic (
p
value)
<
3 + 4
105
23
3
7.96 (0.047)
3 + 4
20
25
6
>
3 + 4
10
6
9
GS = Gleason score; MRI = magnetic resonance imaging; Neg = negative.
MRI-ultrasound fusion biopsy alone missed 39 cases of GS 3 + 4 (blue) but detected an additional 34 cases of GS 3 + 4 cancer overlooked by systematic
biopsy (red). Among 77 cases in which MRI-ultrasound fusion biopsy was negative, systematic biopsy detected 7 cases (9%) of GS 4 + 3 (light blue).
Table 4 – Multivariate regression results for two models
Model 1 outcome: any upgrading (restricted
to
n
= 130 with GS 3 + 4 on systematic
biopsy)
Model 2 outcome: major upgrading
(restricted to
n
= 182 with GS 4 + 3 on
systematic biopsy)
Parameter
p
value
OR
95% CI LL
95% CI UL
p
value
OR
95% CI LL
95% CI UL
Age at biopsy, yr
0.03
1.098 1.008
1.196
0.10
1.138 0.975
1.329
PSA level at biopsy, ng/ml
0.23
1.078 0.955
1.216
0.44
1.072 0.898
1.281
Prostate volume on TRUS, ml
0.63
0.993 0.966
1.021
0.22
1.021 0.988
1.056
No. of previous biopsies
0.06
0.646 0.409
1.021
0.19
0.637 0.327
1.239
Hypoechoic lesion on TRUS
0.23
1.992 0.643
6.171
0.18
0.335 0.067
1.677
No. of cores sampled on systematic biopsy
0.46
0.910 0.711
1.165
0.09
1.421 0.944
2.140
No. of cores sampled on MRI-ultrasound biopsy 0.38
0.827 0.540
1.266
0.06
0.398 0.153
1.032
Time from MRI to biopsy, mo
0.33
0.907 0.747
1.103
0.35
0.874 0.661
1.156
C-index
0.74
0.81
CI = confidence interval; GS = Gleason score; LL = lower limit; MRI = magnetic resonance imaging; OR = odds ratio; PSA = prostate-specific antigen;
TRUS = transrectal ultrasound; UL = upper limit.
Model 1 is for a subgroup of 130 men with GS 3 + 3 on systematic biopsy showing factors associated with any upgrading to Gleason score 3 + 4 or higher on
MRI–ultrasound fusion biopsy relative to systematic sampling. Model 2 is for a subgroup of 182 men with GS 3 + 4 on systematic biopsy showing factors
associated with major upgrading to Gleason score 4 + 3 on MRI–ultrasound fusion biopsy relative to systematic sampling
E U R O P E A N U R O L O G Y 7 2 ( 2 0 1 7 ) 2 7 5 – 2 8 1
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