EURURO Vol. 71 No. 4

The direct comparison of MRI-GB and TRUS-GB within

the same population demonstrates that there is no

statistically significant difference for overall PCa detection.

Though a per core analysis demonstrates a statistically

significant increased incidence of PCa in target biopsy cores

when compared with systematic biopsy cores, with a

relative yield of 3.91 (95% CI: 3.17–4.83). When focussing on

the detection of csPCa MRI-GB has a statistically significant

advantage over TRUS-GB, with a relative sensitivity of

1.16 (95% CI: 1.02–1.32), indicating that MRI-GB signifi-

cantly detects more clinically significant cancers than

TRUS-GB. Consequently, MRI-GB has a statistically signifi-

cant lower yield of insignificant PCa compared with TRUS-

GB, with a relative yield of 0.47 (95% CI: 0.35–0.63). These

results support MRI-GB as a superior alternative to TRUS-

GB. These findings are similar to findings of a previous

meta-analysis comparing TRUS-GB to MRI-GB in which the

authors found a relative sensitivity for MRI-GB of 1.05 (95%

CI: 0.94–1.19) for overall PCa, and a relative sensitivity of

1.20 (95% CI: 1.09–1.32) for csPCa

[41]

Are we ready to abandon systematic TRUS-GB and

completely replace it for MRI-GB? Based on this meta-

analysis, omitting TRUS-GB would result in missing 19% of

all PCa cases, and 10% of csPCa cases. Simultaneously, by

omitting TRUS-GB 50% of the insignificant PCa would not be

detected and would thereby decrease overdiagnosis of

these tumours. The debate on whether this is acceptable or

not is ongoing and a definite conclusion is beyond the scope

of this review.

Which technique for MRI-GB should then be preferred?

The results of this current meta-analysis indicate that

MRI-TB has an advantage over COG-TB in overall PCa

detection (

= 0.02). There does not seem to be a significant

advantage of MRI-TB compared with FUS-TB, or FUS-TB

compared with COG-TB for overall PCa detection. When

focussing on the detection of csPCa, there does not seem to

be a significant advantage of any particular technique,

though the number of studies used for this specific meta-

analysis was limited. When comparing various techniques

of MRI-GB essential components are targeted lesion

characteristics, such as PI-RADS classification, lesion size,

and lesion location. Of 43 included studies only 5% (

= 2)

presented data regarding lesion diameter, and 58% (

= 25)

applied PI-RADS classification. Furthermore the applied

threshold for target biopsy will directly impact the found

tumour yield, and as mentioned earlier the included studies

demonstrate significant heterogeneity regarding applied

threshold. Consequently the results of this meta-analysis are

indicative at best: the number of randomised controlled

trials directly comparing one technique with another is

limited. Within the cohort presented in this meta-analysis

there were only two studies directly comparing two

techniques

[34,42]

. Both studies were not able to demon-

strate significant differences between COG-TB and FUS-TB

on overall cancer and clinically significant cancer detection.

Although a multivariate analysis in one study demonstrated

increased cancer detection in smaller MRI lesions using

FUS-TB when directly compared with COG-TB

[42]

[(Fig._3)TD$FIG]

Fig. 3 – (A) Forest plots of pooled sensitivity of cognitive registration transrectal ultrasound-targeted biopsy (COG-TB), magnetic resonance imagimg-

TRUS fusion TB (FUS-TB), and MRI-TB for all prostate cancer; (B) forest plots of pooled sensitivity of COG-TB, FUS-TB, and MRI-TB for clinically

significant prostate cancer.

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