Imaging and Management of the N0 Neck

Jatin ShahMichiel van den Brekel

Snehal PatelBaris Karakullukcu

Ian GanlyAbrahim Al-Mamgani

Symposium 2015 IAOOSao Paulo

MSKCC – NKI AVL

Options for the N0 Neck Observation

– Based on an estimated low risk of occult metastases: T1 larynx

Staging– CT / MRI / PET– Ultrasound (guided FNAC)– Sentinel node biopsy

Treatment– Elective ND– Elective Radiotherapy

Imaging of the N0 Neck Modalities and developments Sensitivity, Specificity and impact on the

risk of occult metastases What is the maximum accuracy

Imaging of the N0 Neck

Risk reduction might influence management– Imaging should be very sensitive for N0 neck

What risk is acceptable ??

In 1994 Weiss et al. created a decision analysis and demonstrated that when the probability of occult cervical metastasis is more than 20%, the neck should be electively treated.This risk cut-of (Rx) was calculated with three variables:

a = the cure rate with END and no neck recurrence b = the cure rate with observation and late neck metastasisc = the cure rate with observation and no neck metastasis

Rx = (c − 0.97a) ⁄ (0.00376 − 0.0776a − 0.94b + c) = 44.4%

MRI, US and CT

Rely on morphological features

- Nodal size- Central necrosis / irregular enhancement- Signal intensities / enhancement- Indistinct nodal margins- Gross extracapsular extension

Easy Cases

NegativePositive

13

PET-CT: very promising

BJ de Bondt: Diffusion weighted MRI (2009)

CT misdiagnosis

False Positive PT-CT

Accuracy CT and MRI N0 neck No Sensit Specif

Stern CT 53 40 92 Friedman CT 68 68 90

MRI 16 80 82 Moreau CT 32 50 86 Hillsamer CT 11 60 83

MRI 9 66 83 Yucel MRI 20 57 93 Vd Brekel CT 86 49 78

MRI 83 55 88 Rhigi CT 25 60 100 Okura CT 132 52 81

MRI 60 61 84

Total CT 407 53 82 MRI 188 60 85

PET (CT) in cN0 casesAuthor Neck

sN+ Sensitivity Specificity NPV

Myers 1998 14 30% 79% 100%

Civantes 2001 18 61% 30% 100% 45%

Hyde 2003 18 22% 0% 87% 77%

Brouwer 2003 15 67% 92%

Wensing 2006 30 30% 33% 76% 73%

Schroder 2006 36 25% 67% 85% 88%

Krabbe 2008 38 21% 50% 97% 88%

Ozer 2012 112 57% 82% 59%

Sohn 2015 49 51% 55%

Sensitivity US-FNAC N0 NeckAuthor Tumor Neck Sides Sensitivity Specificit

yvdBrekel (1993) HNSCC 43 73 100Righi (1997) HNSCC 33 50 100Takes (1998) HNSCC 64 48 100Nieuwenhuis (2002) Oral SCC (T3-4) 23 71 100

Nieuwenhuis (2002) Oral SCC (T1-2) 37 25 100

Hodder (2000) Oral SCC (T1-4) 33 58 100Borgemeester (2009)

Oral SCC (T1-2) 37 18 100

Borgemeester (2009)

HNSCC (T3-4) 128 39 100

Wensing (2010) Oral (T1-2) 224 78 100

Sensitivity versus radiologist

Radiologist

Neck sides examined HP positive

Sensitivity (%)

1 39 11 9

2 29 14 29

3 31 11 45

4 43 17 53

US-FNAC vs CT, MRI, US: meta-analysis

De Bondt et al. Eur. J. Radiol. 2007

Computed tomography versus magnetic resonance imaging for diagnosing cervical lymph node metastasis of head and neck cancer: a systematic review and meta-analysis. Sun J, Li B, Li CJ, Li Y, Su F, Gao QH, Wu FL, Yu T, Wu L, Li LJ. Onco Targets Ther. 2015;8:1291-313

Analysis of sentinel node biopsy combined with other diagnostic tools in staging cN0 head and neck cancer: A diagnostic meta-analysis. Liao LJ, Hsu WL, Wang CT, Lo WC, Lai MS. Head Neck 2015

Hypothetic 100 cN0 patients, 40 pN+

Sensitivity 56%, Specificity 100% (USgFNAC)– Neck treatment in 22 (4-9% recur !!)– Wait & See policy in 78

» Undertreatment in 18 (30-70% salvaged) Sensitivity 56%, Specificity 79% (MRI)

– Neck Treatment in 35» Overtreatment in 13

– Wait and See in 65» Undertreatment in 18 (30-70% salvaged)

Maximum Sensitivity of Imaging

Depends on imaging criteria, spatial resolution, contrast, uptake of tracers

BUT ALSO ON THE SIZE OF THE METASTASIS

The challenge is to detect metastases smaller than 3-4-5 mm

MICROMETASTASES IN 96 cN0 ND SPECIMENS

van den Brekel et al. Laryngoscope 1996

In 25% of pN+, cN0 necks only metastases smaller than 25% are present

Conclusions Imaging can detect 50-60% of occult

metastases according to literature As all studies used HP as gold standard,

the reported sensitivities are overestimated

So far USgFNAC has the highest accuracy in well trained and motivated doctors

At least 25-30% of occult metastases cannot be detected with imaging