Download Mean ADC node

Diffusion Weighted Magnetic Resonance Imaging as a
Biomarker to Determine Human Papilloma Virus Positivity
in Oropharyngeal Squamous Cell Carcinoma
P Jabehdar Maralani1, J Beelen2, D Patel1, D Enepekides1, K Higgins1, S Symons1, R Aviv1
1University
of Toronto and Sunnybrook Health Sciences Centre, Toronto, ON, Canada
2The University of Western Ontario, London, ON, Canada
No.
No Disclosures.
Introduction
• There has been a recent increase in incidence of oropharyngeal
squamous cell carcinoma (OSCC) believed to be due to human
papilloma virus (HPV).
• HPV positive (HPV+) OSCC has a much better prognosis compared to
HPV negative (HPV-) disease and may benefit from deintensified
treatment.
• HPV+ OSSCs have larger and more cystic lymph nodes.
• Diffusion weighted imaging can quantitatively assess cell density.
• We hypothesize that:
HPV+ lymph nodes have more facilitated diffusion
compared to HPV- lymph nodes and this can be used as an
imaging biomarker to predict HPV positivity.
Materials and Methods:
• IRB approved with waiver of informed consent
• Pretreatment MRIs of 22 HPV+ and 11 HPV- patients with pathology
proven OSCC were retrospectively reviewed.
• HPV status was determined by p16 immunostaining technique.
• Axial T1 pre-contrast images were coregistered with apparent diffusion
coefficient (ADC) maps using SPM8 (Wellcome Trust Centre for Neuroimaging,
UCL, UK).
• Then, using Analyse 12.0 (Mayo Clinic, MN) the tumor and the largest ipsilateral
level 2 lymph node were contoured separately to produce two volumes of
interest (VOI) in each case.
A
B
Examples of a region of interest drawn over a left sided OSCC
(Panel A) and a right sided lymph node (Panel B)
• Maximum, minimum and average ADC values in each VOI as well as
the volume of tumor and the volume of the ipsilateral level 2 lymph
node were calculated and recorded in each case.
• The results are expressed as average ± standard deviation. Two-tailed
student t-test was used to compare average values.
Results
Table 1
Age
Male/female
ratio
1.5T vs. 3T
MRI
HPV+
56.05±11.66
HPV64.74±8.43
P value
0.03
18/4
11/0
0.2
5 vs 17
4 vs 7
0.6
Table 2
Maximum ADC
tumor
Minimum ADC
tumor
Mean ADC tumor
Volume of tumor
Maximum ADC
node
Minimum ADC
node
Mean ADC node
Volume of the
node
HPV+
HPV-
P value
2451.38±442.13
2482.32±364.67
0.9
177.38±263.02
348.91±274.67
0.5
1063.96±469±89
97.12±59.01
1102±158.26
10.26±82.98
0.2
0.9
27.86±36.12
2818.95±571.33
0.7
359.33±411.85
140.00±275.45
0.2
1358.62±187.07
1140.10±259.96
0.07
64.28±50.64
16.68±14.57
0.09
• As demonstrated on table 2, there was a trend towards higher mean
ADC values in HPV+ vs. HPV- lymph nodes (P=0.07).
• There was also a trend towards larger volume of HPV+ vs. HPV- lymph
nodes (P=0.08).
Conclusion
• There was a trend towards higher mean ADC values in HPV+ vs. HPVlymph nodes representing more facilitated diffusion. This is consistent
with more cystic changes in HPV+ nodes.
• Diffusion weighted imaging can serve as a promising biomarker to
predict HPV positivity in oropharyngeal squamous cell carcinoma.
• Increased patient recruitment can increase the statistical power of
this study which is already undergoing in our institution.
References
1. Nakahira M, Saito N, Yamaguchi H et al. Use of quantitative diffusionweighted magnetic resonance imaging to predict human papilloma virus
status in patients with oropharyngeal squamous cell carcinoma. Eur Arch
Otorhinolaryngol. 2014: 271:1219-25
2. Chaturvedi AK, Engels EA, Pfeiffer RM et al. Human papillomavirus and
rising oropharyngeal cancer incidence in the United States. J Clin Oncol
2011: 29:4294–4301
3. Applebaum KM, Furniss CS, Zeka A et al. Lack of association of alcohol
and tobacco with HPV16- associated head and neck cancer. 2007: J Natl
Cancer Inst 99:1801–1810
4. Rainsbury JW, Ahmed W, Williams HK et al. Prognostic biomarkers of
survival in oropharyngeal squamous cell carcinoma: systematic review
and meta-analysis. Head Neck. 2013: 35:1048-55
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