Transcript MultiParametric Prostate MRI and MR/US fusion biopsy

Utilizing MRI in Prostate Cancer Diagnosis and
Fusion Biopsy
Ari Goldberg MD,PhD
Dept. Radiology
Loyola University Medical Center
Prostate CA
► ~1
in 7 men diagnosed with prostate CA
at some point in lifetime
► ~241,000 new cases in 2015
► Mortality expected to be ~28,000 in 2016
in the US
► Traditional diagnosis:
 PSA, DRE
 TRUS
Staging
 Gleason
►Combination
of primary and secondary pathologic
morphology, each on 1-5 scale.
 5 = poorly-differentiated
 Ex: 4 + 3 = 7 = Dominant pattern of poorly organized cells
with pockets of well-organized gland.




Low-Risk: PSA < 10, Gleason < 6
Medium-Risk: PSA 10-20, Gleason 7
High-Risk: PSA>20, Gleason > 7
Imaging
►CT
abdomen/pelvis
►MRI
►Nuclear studies (PET, bonescan)
Biopsy
 TRUS (12 core)
►~1.2
Million annually
►~0.04% of the gland is sampled
 NPV?
► Cancer detection rates of 27-40%
► Incorrect characterization
 PPV? Non-clinically-significant cancer
 Prostate Cancer is only solid-organ tumor
currently diagnosed without routine imaging
Prostate MRI
► Advantages
of MRI:
 Superior tissue characterization
►Normal vs. abnormal tissue
►Gland architecture
 Non-invasive
 No ionizing radiation
 Visualization of gland within the surrounding anatomy
 Regional evaluation for metastatic disease.
Traditional prostate MR indications
► Staging
for biopsy-proven CA
►Extent
within gland
 Location
 Identify multifocal disease/upstage
►Extra-glandular





spread
ECE
Seminal Vesicle
Fat
Bones
Nodes
 MRI has altered care to or from nerve-sparing
between ~25% of time in multiple studies
(including internal LUMC data)
MP vs ER
► ER




coil
Increased SNR, spatial resolution
Spectroscopy
Decreased patient motion
Disadvantages
► Patient discomfort
► Posterior artifact
► MP
 3T vs 1.5T
Increased SNR, spatial resolution
► Increased temporal resolution
► Increased field inhomogeneity
► Recent spectroscopy
►
►
Overall: MP for staging, ER for diagnosis
ER Coil Workflow
Patient – light diet preceding day
► Enema at home
► IV access
► Minimal rectal exam followed by coil insertion with
xylocaine
► Inflation of balloon
►
 Barium
►
Readjustment common, ~5 mins
Standard Prostate MR
Standard Prostate MR
T2W
T1W
Extracapsular Extension
Advanced Disease
What are other MR indications?
► Diagnosis
 +PSA/-TRUS
 +PSA
 AS
► Post-surgical
surveillance
 Recurrent tissue
 Nodes, bones
Multi-parametric MRI for Diagnosis
► Sequences/parameters
characterize lesions:




used to detect and
T1
T2
Diffusion
Dynamic Contrast enhanced
► Significantly
more specific
Advanced sequences
► Dynamic
imaging
Contrast Enhanced (DCE) T1
 Angiogenesis
 Rapid wash in and washout
 Better at 3T (temporal and spatial resolution)
► Diffusion
Imaging
 Increased diffusion restriction in tightlypacked malignant cells
► 3D
voxel Spectroscopy
 Malignant cells have increased choline/citrate
 Chemical shift imaging
Suspicious MRI characteristics
►
►
►
Low T2
 Peripheral zone
 Central “charcoal” appearance
Abnormal diffusion
 Can measure quantitatively
 High B-field best
Fast wash-in/wash-out kinetics
 Post-processing generates wash-in/out curves of voxel
signal vs. time.
DCE
Very sensitive, not very specific
T2+Diffusion
Interpretation
►
►
PIRADS (Prostate Imaging Reporting And Data System)
PIRADS II
 1-5
►
Peripheral zone and Transitional zone get separate scores. Peripheral
weights DWI and Transitional weights T2:
 3=Indeterminate
 4=Probable
 5=Highly likely. More focal abnormal signal and/or size > 1.5 cm and/or
capsular involvement.
► DCE
►
only plays minor role
 Studies have found that more focal and more quantitatively
abnormal diffusion and post-contrast signal correlates with
increased Gleason score but is not yet quantitative.
Accuracy: mpMRI reduces the detection of low-risk PCa and reduces
the number of men requiring biopsy, while improving the overall rate of
detection of intermediate/high-risk PCa European Urology, Volume 66 Issue 1, July 2014,
Pages 22-29
MRI for diagnosis?
► Abnormal
signal not yet sufficient
► Biopsy still required
► So, does it make sense to do diagnostic MRI
on patient with +PSA? Or +PSA/-TRUS?
 Result of suspicious signal focus not helpful
without ability to localize for biopsy.
In-Gantry MRI
► Technically
challenging
► Less comfortable
► COSTLY!
 Avg time ~1.5 hr
 Scanner time premium
 Access
► Low
Urologist acceptance
MRI-US fusion-guided biopsy
►
►
Generate MRI prostate “mold” from MRI images
Tumor depicted within the virtual mold
MRI-US fusion-guided biopsy
►
►
►
Virtual mold with in-situ lesion is transferred to Fusionbiopsy system server connected to US machine.
Operator uses TRUS probe to sweep prostate and generate
US-based prostate volume.
The two volumes are fused
MRI-US fusion-guided biopsy
MRI/TRUS
TRUS probe has a sensor which lets the computer know its position
TRUS probe can then be guided to the lesion for precise throws
NIH experience
► Published in JAMA 1/27/15
► 1003 patients from 2007 to
2013
 All received MRI and subsequent guided-Bx when
indicated
 All received standard 12-core Bx
 Whole-gland pathology available in 170 patients
► MR-guided
Bx yielded:
 30% greater high-risk cancers
 17% fewer low-risk cancers
 Overall significantly fewer false-negatives for >low-risk
disease
► Multiple
studies in past 2 years support these
numbers
LIJ/NorthShore MRI/US experience
100
90
80
70
60
50
40
30
20
10
0
Fusion
12-Core
MR 3
4
5
Total
Their Conclusions
► Degree
of MR suspicion correlates directly
with incidence of cancer on pathology.
 ~90% of patients with high-suspicion (5) on MR
are diagnosed with cancer on biopsy.
► 55%
over all cancer detection rate
 20-40% increased detection of Gleason > 7
 Excludes low-risk cancers which are missed by
~15-20%
► 35-45%
cancer detection in patients with
previous negative 12-core
► 20% upstage in patients on AS
Indications for Prostate MRI + fusion biopsy
► +PSA,- Negative biopsy
 Significant part of LUMC volume
 > 50 cases of (+) disease in setting of multiple-negative
and saturation-negative, consistent with literature
► AS




Low risk disease = low-grade and localized
Yearly monitoring (biopsy)
Establish baseline
Yearly MRI +/- fusion
► Localize
► Elevated
new/growing lesion for biopsy
PSA or abnormal DRE
 Thus far covered by CMS and private insurers
Negative TRUS but….
LUMC data, % Ca detected
70
60
50
40
Fusion
G>7 std
G>7 Fus
30
20
10
0
MR 3
MR 4
MR 5
Things to Think About
► Imaging
time ~45 mins
 1 hour slot
► MRI
Prostate = MRI pelvis w/wo + 3D code
► GFR > 30
 OK to do w/o contrast
► Who
puts in ER coil?
► System for image transfer
► TAT
► OK to do w/o ER coil
► Patient education
So, Evolving utilization
► MRI
+ Fusion Bx as diagnosis
► AS
 Follow with MRI? MRI + fusion-biopsy?
► Role
in focal treatment monitoring?
Who will perform Biopsies?
► Radiologists
at LUMC trained in Fusion Bx
 But we don’t do them
► Urologists
have long history of in-office US
biopsy
► Fusion Bx platforms being purchased by
most Urology groups in the Chicago area
► Urologists not interested in losing patients
A Rising Tide…
► Urologists
with Fusion Bx US system mostly
still need an MRI partner
 Connect!
►Office
talks
►Conferences
►Media (Youtube, email)
►Manage access – no detail too small
► Started
LUMC program Jan 14
 > 700 so far
 Avg of 3 per day at this time
► Growth
enabled Research Fellow