Fusion prostatic biopsy

1. Mohammad Ihmeidan PGY5

2. • MRI is an effective way to visualize prostate tumors.
• Multiparametic MRI combines anatomic, diffusion-
weighted (DWI), and dynamic contrast-enhanced (DCE)
imaging
• Anatomic imaging provides the highest spatial resolution
images in which tumors appear as low-signal intensity
areas in T2-weighted images.

3. • DWI measures differences in the random Brownian motion of
water, or diffusion, which is more rapid in the normal gland
than in tumors because of the high cellularity of tumors.
• DCE MRI takes advantage of differences in the vascularity of
tumors and normal tissue.
Due to angiogenesis, vascularity is higher in tumors than in
surrounding tissue, resulting in higher rates of uptake and
washout of contrast material.
• A recent meta-analysis indicated that multiparametric MRI has
an estimated sensitivity of 0.74 (95% CI, 0.66–0.81),
specificity of 0.88 (95% CI, 0.82–0.92).

4. • With the advent of advanced imaging techniques and
image-guided biopsy for the detection of prostate cancer
(PCa), the concept of fusion biosy gained popularity.

5. • Fusion :t
he process of
joining two or
more things
together to form
a single entity

6. • The main three approaches to TB include
• 1-cognitive fusion (COG-TB)
• 2-software-based fusion (FUS-TB)
3-in-bore or in-gantry TB (IB-TB).

7. • The simplest way of integrating MRI information into
TRUS guided biopsies.
• If a radiologist reports lesions on a sector map with a
suspicious lesion, an experienced urologist may guide
the needle exactly into this area.
• Cognitive approach has some limitations , most
importantly the large rotational differences between the
prostate MRI and TRUS orientations that make targeted
biopsy difficult for operators even experienced
surgeon.

9. • MR/US Fusion-Guided Prostate Biopsy
• MR/US fusion-guided biopsy depends on the creation of a 3D
image of the prostate gland that shows the location, size, and
shape of a suspected tumor.
• This image is created from an MRI performed prior to the
biopsy procedure
• During procedure, the stored MR image is uploaded into a
dedicated device that aligns it with real-time US
• The urologist can then direct the biopsy tool to sample the
suspected tumor.

13. • The MR/US fusion-guided biopsy device records the
precise location of the biopsy site.
• Subsequent sampling of the same site can be obtained at
a later date with an accuracy of within 1–2 mm.

14. • Several software platforms using a transrectal or perineal
approach are available on the market.
• Good tool for active surveillance .
• Repeat biopsies under active surveillance may be guided
more precisely to initially positive areas, which can
increase the safety of such protocols.
• Could be used in ablative procedures (eg, high-intensity
focused ultrasound therapy, cryotherapy. With fusion
biopsies it is possible to create an accurate 3D model of
cancer areas of the prostate and to transfer this model to
appropriate treatment systems.

15. • Results for the largest MRI/TRUS fusion biopsy
cohort of 1003 men were published by Siddiqui et al
in 2015.
• The primary study objective was to compare
MRI/TRUS fusion and standard biopsy approaches
for detection of high-risk PC (Gleason score 4 + 3); a
secondary endpoint was detection of low-risk PC
(Gleason score 3 + 3 or low-volume 3 + 4).
• In comparison to standard biopsy, fusion biopsy
detected 30% more high-risk cancers and 17% fewer
low-risk cancers.

18. • mpMRI information can be used to guide biopsies directly in
the MRI gantry .
• Special nonferromagnetic guiding systems are necessary for
this sophisticated technique.
• Different systems with different biopsy approaches are
currently available on the market.
• In 2011, Roethke et al reported results for in-magnet biopsies
in patients with previous negative results. The detection rate
was significantly higher than the rate for TRUS-guided
biopsies in that settings.

20. • While IB-TB might have the potential to be the most
precise target strategy as it does not require ultrasound
image fusion and lesions are directly targeted on
MRI,some authours argue that CDR is similar to other
fusion strategies.

21. • Has some limitations
IB-TB is expensive and time-consuming, requiring an
MRI suite and MRI-compatible equipment and supplies,
as well as the expertise to use them.
• Approximately 15% of csPCa are invisible on MRI, and
therefore will not be detected on IB-TB .
• In addition, Systematic Bx, which may improve CDR
when combined with TB, cannot be performed during IB-
TB.
• Given these limitations, some authors advocate the use
of IB-TB specifically for very small lesions, and/or repeat
biopsy when clinical suspicion is high but prior TB are

23. • Visual-estimation may be the most straightforward choice
for larger, diffuse lesions.
• In-bore used in selected cases for men with ongoing
suspicion of cancer despite negative visual-estimation or
image-fusion biopsy.

24. • A question urologists face every day is
whether they should only take biopsies
from MRI-suspicious lesions?
• The answer is mostly NO , as mapping
biopsies supplemented with targeted
biopsy remain the gold standard for tumor
detection.

25. • It is not yet known whether the use of targeted biopsies will
affect the clinical outcomes of patients diagnosed with prostate
cancer.
• However, the current method of systematic biopsy, in which as
many as 12 cores may be sampled, can lead to overdetection
of small indolent tumors and may underdetect clinically
significant tumors.
• Up to 50% of tumors detected by this method may not be
clinically relevant; and although many patients undergo active
• surveillance, some will undergo prostate cancer treatment
unnecessarily.

26. • At the same time, 28,000 men die from prostate cancer each
year in the US and these numbers might decrease if more
high-risk cancers were accurately detected at an earlier stage.
• Further studies are necessary to discover if MR/US fusion-
guided biopsies will improve the ability to categorize the risk of
tumor growth and, on this basis, reserve aggressive treatment
for patients at intermediate to high risk while avoiding
treatment in patients at low risk.
• For men with apparently low-risk prostate cancer who are
considering active surveillance, MR/US fusion-guided biopsy
can be useful in detecting higher risk clinically significant
disease that was undetected by the initial biopsy, identifying
men in whom active treatment is more appropriate. Further
study is needed to establish these suggestions.

27. Thank You

28. • 1-Kuru, T. H., Herden, J., Zugor, V., Akbarov, I., Pfister, D., Porres,
D., & Heidenreich, A. (2016). How to Perform Image-guided Prostate
Biopsy: In-bore and Fusion Approaches. European Urology Focus,
2(2), 151–153. doi:10.1016/j.euf.2016.03.016
• 2-Visual-estimation (cognitive), image-fusion (software) and in-bore
targeted prostate biopsy: is there an optimal approach?
Christopher C Khoo, Martin J Connor and Hashim U Ahmed
• 3-MR/US Fusion Imaging as an Aid to Prostate Biopsy/radiology
rounds/2016-14-1
• 4-Comparative Effectiveness of Techniques in Targeted
• Prostate Biopsy Dordaneh Sugano 1 , Masatomo Kaneko 1,2,
Wesley Yip 1 , Amir H Lebastchi 1, Giovanni E. Cacciamani 1 and
Andre Luis Abreu 1,*