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Diagnostic Accuracy of Magnetic Resonance
Imaging Using Unenhanced Techniques for
Detection of Recurrent Vestibular
Schwannomas
Jamie Williams MD, Carrie Carr MD, Laurence Eckel MD, John Lane MD
ASNR 54th Annual Meeting
May 2016
eP-85
©2016 MFMER | slide-1
Disclosures
• None
©2016 MFMER | slide-2
Purpose
Background: Vestibular schwannomas
• Benign, slowing growing tumor arising from 8th
cranial nerve
• Varied patterns of growth after diagnosis:
• 40-50% show no growth
• 40-50% demonstrate growth
• <10% demonstrate regression
• Management strategies:
• Active surveillance vs.
• Surgery, with goal to resect tumor and
salvage facial nerve
Nikolopoulos et al. (2010)
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Purpose
Background: Post-operative surveillance
• Poor correlation between tumor growth and
symptoms
• Approximately 6% 3-year recurrence rate after
resection
• Increased risk of recurrence: subtotal
resection, nodular enhancement on initial
postoperative MRI
• On average, recurrent growth is
approximately 2.3 mm/year
• MRI with gadolinium-enhanced T1 weightedimaging (T1WI) is current gold standard for
recurrence
Rosenberg (2000)
Carlson et al. (2012)
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Purpose
Background: Gadolinium-enhanced MRI
• Duration and cost of gadoliniumenhanced MRIs are greater than noncontrast MRIs
• Recent evidence of gadolinium deposition
in neuronal tissue after intravenous
exposure to gadolinium-based contrast
agents results
• Dose-dependence relationship
• Clinical significance unknown
McDonald et al. (2015)
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Purpose
Background:
Noncontrast, high resolution MRI (3D T2/T2*)
• High signal-to-noise ratio per unit of time
• Abele et al. (2009) demonstrated high
accuracy, specificity, and sensitivity of 3D
T2/T2* in detection of small internal
auditory canal lesions
Schleffler & Lehnhardt (2003)
Abele et al. (2009)
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Purpose
Objectives
• Evaluate the diagnostic accuracy of
noncontrast, high resolution MRI (3D
T2/T2*) for the detection of vestibular
schwannoma growth following surgical
resection
• Potential with 3D T2/T2* to:
• Reduce time and cost of scanning
• Avoid patient exposure to gadolinium
(and therefore gadolinium tissue
deposition)
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Material and Methods
Retrospective Chart Review
• Data abstracted from electronic medical record
• Included patients who underwent resection Jan.
2001 to Jan. 2011:
• Experienced recurrence during follow-up thru
January 2015 (N=13)
• Received 3D T2/T2* and contrast
enhanced MRI after resection (n=41)
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Material and Methods
Summary of Cases
Number of patients
Total number of follow-up MRIs examined
13
41
Age at treatment, yr, mean (range)
50 (21-86)
Sex, no.
Female
Male
Pre-treatment tumor size, mm, mean (range)
9
4
19 (6-40)
Side of tumor, no.
Right
Left
Year of initial surgery, range
Type of initial resection, no.
Gross Total Resection
Near Total Resection
Subtotal Resection
Number of follow-up MRIs per patient, mean (range)
Year of follow-up MRIs
6
7
2002-2011
4
1
8
3.2 (1-6)
2005-2014
Underwent 2nd treatment with gamma knife during follow-up
Yes
No
7
6
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Material and Methods
Retrospective Review of Follow-up MRIs
• Three blinded CAQ neuroradiologists
retrospectively reviewed all follow-up MRIs:
• Only axial 3D T2/T2* images
• Only axial gadolinium-enhanced thin-section
T1-weighted images (PostGad T1WI)
• For each, respective images from initial
postsurgical MRI was provided for comparison
• Asked to assess for presence or absence of
tumor progression
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Material and Methods
Example of Retrospective Review
Initial Postop MRI
3D T2/T2*
PostGad
T1WI
Surveillance MRI
vs.
vs.
+/Progression?
+/Progression?
Neuroradiologist
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Material and Methods
Data Analysis
• Evaluated agreement between examiners within
each sequence
• For each examiner, determined whether
progression was detected more frequently with
one sequence versus the other
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Results
Examiner Agreement
Sequence
Krippendorff’s alpha
3D T2/T2*
0.815
PostGad T1WI
0.826
• Krippendorff’s angle
• Ranges between –infinity and 1
• 1= Perfect agreement
• ≥0.800 typically accepted as high agreement
Therefore, high agreement between the
examiners on both sequences
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Results
Examiner 1
Post Gad
No progression
Post Gad
Progression
Total
3D T2/T2*
No progression
24
4
28
3D T2/T2*
Progression
2
11
13
Total
26
15
41
McNemar’s test p-value = 0.69
Examiner 1: No difference in detection of
progression between the sequences.
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Results
Examiner 2
Post Gad
No progression
Post Gad
Progression
Total
3D T2/T2*
No progression
27
3
30
3D T2/T2*
Progression
1
10
11
Total
28
13
41
McNemar’s test p-value = 0.63
Examiner 1: No difference in detection of
progression between the sequences.
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Results
Examiner 3
Post Gad
No progression
Post Gad
Progression
Total
3D T2/T2*
No progression
22
3
30
3D T2/T2*
Progression
2
14
11
Total
24
17
41
McNemar’s test p-value = 0.99
Examiner 1: No difference in detection of
progression between the sequences.
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Results
Interesting Case 1: Progression detected earlier on PostGad T1WI
Initial Postop MRI
3D T2/T2*
PostGad
T1WI
First Surveillance MRI
Sequential
Follow-up MRI
All 3 examiners:
No Progression
All 3 examiners:
Progression
On the sequential follow-up MRI, all 3 examiners reported, on both sequences, that there
had been progression since initial postoperative MRI
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Results
Interesting Case 2: Progression detected earlier on bSSFP
Initial Postop MRI
3D T2/T2*
PostGad
T1WI
Follow-up MRI
Sequential
Follow-up MRI
All 3 examiners:
Progression
All 3 examiners:
No Progression
On the sequential follow-up MRI, 2/3 examiners on the 3D T2/T2* and 3/3 examiners on the
PostGad T1WI reported that there had been progression since the initial preoperative MRI
©2016 MFMER | slide-18
Results
Interesting Case 3: Subtle progression detected on both sequences
Initial Postop MRI
3D T2/T2*
PostGad
T1WI
Follow-up MRI
All 3 examiners:
Progression
All 3 examiners:
Progression
Although the progression was subtle, 3/3 examiners detected it on both
sequences.
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Discussion
Limitations
• Retrospective
• Many patients in this study had their surveillance
MRIs performed locally
• Variable image quality secondary to various
scanners and protocols
• Variable frequency of follow-up MRIs
• Some MRIs had to be excluded from the study
due to lack of 3D T2/T2* technique
• Early follow-up MRIs (prior to 2005)
• Some examinations from outside institutions
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Conclusions
• No substantial difference in the diagnostic
accuracy between high resolution, noncontrast MRI (3D T2/T2*) and
gadolinium-enhanced T1-weighted MRI
for the detection of recurrent vestibular
schwannomas
©2016 MFMER | slide-21
References
Adele
TA, Besachio DA, Quigley RK, et al. Diagnostic accuracy of screening MR imaging using unenhanced axial
CISS and coronal T2WI for detection of small internal auditory canal lesions. AJNR Am J Neuroradiol 2014 July17.
[Epub ahead of print]
Carlson ML, Van Abel KM, Driscoll CL, et al. Magnetic resonance imaging surveillance following vestibular
schwannoma resection. Larnygoscope 2012;122:378-388
McDonald RJ, McDonald JS, Kallmes DF, et al. Intracranial gadolinium deposition after contrast-enhanced MR
imaging. Radiology 2015; 275(3):772-782
Nikolopoulos TP, Fortnum H, O’Donoghue G, Baguley D. Acoustic neuroma growth: a systemic review of the
evidence. Oto Neurotol 2010;31:478-485
Rosenbeerg SI. Natural history of acoustic neuromas. Laryngoscope 2000;110;497-508
Scheffler K and Lehnhardt S. Principles and applications of balanced SSFP techniques. Eur Radiol 2003;13:24092418
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Thank you for your time and attention.
Please address correspondence to Jamie Williams MD, Department of Radiology Mayo
Clinic Rochester, email [email protected]
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