imaging of carcinoma thyroid

1. IMAGING OF THYROID CANCER
-Dr.A.Joseph Stalin(M.Ch PG)
PROF RR UNIT
CENTRE FOR ONCOLOGY
GOVT ROYAPETTAH HOSPITAL
CHENNAI

2. An image is not simply a trademark, a design, a slogan or
an easily remembered picture. It is a studiously crafted
personality profile of an individual, institution,
corporation, product or service.
The paradox of reality is that no
image is as compelling as the one
which exists only in the mind's eye

3. CONTENT
Role of Imaging in
• A.Evaluation of Thyroid nodule
• B.Preop evaluation
• C.Followup/Surveillance
• D.Therapeutic purpose
Imaging features in common malignancy
Recent advances

4. IMAGING MODALITIES
• X RAY
• USG
• RADIONUCLEOTIDE IMAGING
• CT
• MRI
• PET

5. A.Evaluation of Thyroid nodule
• Clinically palpable nodule :4-7 % of general
population.
• USG : 70 % of adult population.
• CT/MRI : Incidentaloma- 14.5 %.
• 9-13 % incidence of malignancy in thyroid
nodule.

6. Evaluation of thyroid nodule
Clinical examination
Imaging
Pathology
History

7. Imaging
• USG ( High resolution)
• I -123 SCINTIGRAPHY (Low TSH)

8. Diagnostic thyroid USG
• Should be performed in all patients with
thyroid nodule.
• High resolution USG – most sensitive test to
detect thyroid lesion
• During USG- Look for coincidental nodules.
Select a nodule for FNA.
Look for nodes in neck.

9. Thyroid US answers following questions
• Whether Nodule corresponds palpable lesion?
• Cystic or solid ?
• How large?
• Benign or suspicious?
• Any other nodule in gland?
• Any suspicious cervical node?

11. MNG

12. USG- Features of malignancy
• Finding :
– Hypoechogenecity.
– An absent halo.
– Irregular margins.
– Taller than wide shape.
– Presence of micro-calcifications
– Increased intranodular vasculariry.
– Extrathyroidal extension.
– Nodal disease in neck.
• No findings are definitive.

13. ADENOMA

14. Thyroid USG
Normal thyroid Papillary Ca. Thyroid

15. Indication for USG guided FNA
1. Non-palpable nodule
2. Predominantly cystic nodule
3. Posteriorly located nodule
4. Repeating FNA for non-diagnostic nodule

16. Palpation-guided versus US-guided
FNA Cytology of thyroid nodules
• Diagnostic accuracy - P-FNA 60% and US-FNA - 80% .
• Inadequate specimen rate - 11.2% in the P-FNA group, 7.1%
in the US-FNA group .
• Sensitivity, positive predictive value, and negative predictive
value increased significantly with ultrasound guidance .
Izquiero R Endocr Pract. 2006 Nov-Dec;12(6):609-14

17. Pitfalls of USG
• Retrosternal extension
• Paratracheal tissues
• Extrathyroidal extension
• Retropharyngeal/paraesophageal nodes

18. THYROID SCINTIGRAPHY

19. Differential Diagnosis
COLD NODULE
(8-25 % chance of
malignancy)
• Thyroiditis
• Fibrosis
• Cyst
• Non-functioning
Adenoma
• Multinodular Goiter
• Malignancy
HOT NODULE
(malignancy rare)
• Funcioning Adenoma
• Thyroiditis

21. B.PRE OP EVALUATION
• To determine extend of primary tumour
• To evaluate regional nodal metastasis.

22. Extension of primary tumour
• Spread outside thyroid capsule- strap and
sternomastoid muscle involvement
• Spread to laryngx or trachea
• Esophageal invasion
• Vascular invasion
• Spread to prevertebral muscles or bone
• Mediastinal extension

23. TRACHEAL INVASION
• Atleast one of follwing CT criteria fulfilled :
• Tumor in contact with 180° or more of the tracheal
circumference (grades 3 and 4);
• Deformity of the tracheal lumen at the level of the
mass;
• Focal irregularity, thickening, or bulging in the mucosal
portion adjacent to the mass.

24. ESOPHAGEAL INVOLVEMENT
At least one of the following CT criteria were
fulfilled:
• Tumor in contact with 180° or more of the
esophageal circumference (grades 3 and 4) .
• Loss of the normal esophageal structures (wall
and lumen)

25. CAROTID VESSEL ENCASEMENT
• Invasion of the CCA or IJV was diagnosed if the
tumor was in contact with 180° or more of the
circumference of the vessel (grades 3 and 4).

26. Recurrent laryngeal nerve involvement
At least two of the following three criteria were fulfilled:
• completely effaced fatty tissue in tracheoesophageal
groove.
• More than 25% of the circumference of the tumor
abutted the capsule at the posterior portions of the
thyroid (posterior extracapsular invasion).
• Ipsilateral vocal cord palsy was present on the basis of
CT findings such as paramedian cord, anteromedial
deviation of the arytenoid cartilage, enlarged pyriform
sinus, or enlarged laryngeal ventricle

27. Recurrant laryngeal nerve involvement
• CT scan obtained at level
of vocal cords shows
• Anteromedial deviation
of arytenoid cartilage
(short arrow),
• Enlarged pyriform sinus
(long arrow),
• Enlarged laryngeal
ventricle (arrowhead) on
left side.

28. • Mass replacing entire right thyroid
lobe, isthmus, and medial portion
of left lobe (arrows).
• Tumor surrounds ≥ 180° of
circumference of trachea and
esophagus and completely
encircles right common carotid
artery (arrowhead).
• Right internal jugular vein has
been obliterated.
• Posterior tumor extension and
completely effaced fatty tissue in
right tracheoesophageal groove
indicate tumor invasion of
recurrent laryngeal nerve

29. • Contrast-enhanced CT scan shows
large heterogeneous mass (short
arrows) in left lobe and isthmus of
thyroid.
• Tumor is in contact with ≥ 180° of
circumference of trachea. Focal
bulging in mucosal portion of
trachea (long arrow) suggests direct
tumor invasion into tracheal lumen.
• Tumor encroaches esophagus
(arrowheads) but surrounds < 180°
of circumference of esophagus.
• Posterior tumor extension and
completely effaced fatty tissue are
evident in left tracheoesophageal
groove

30. LIMITATION WITH IMAGING
Limitation :
circumferential invasion is often
underestimated
Involvement is more when assessed
pathologically

31. X RAY

32. USG
• It is the primary/only modality of imaging
needed in
• -isolated thyroid mass
• - no palpable lymphadenopathy

33. Thyroid USG
Normal thyroid Papillary Ca. Thyroid

34. INDICATION FOR CT/MRI
• Fixed immobile thyroid mass
• Palpable lymphadenopathy
• Hoarseness ,dysphagia , dyspnoea.
• Retrosternal extension

35. CT
• More sensitive /specific than USG&MRI in detecting nodal mets.
• Contrast interferes with iodine uptake
• The mean sensitivity, specificity, and accuracy of CT were as follows:
59.1%, 91.4%, and 83.2% for tracheal invasion; 28.6%, 96.2%, and 90.7%
for esophageal invasion; 75.0%, 99.4%, and 98.8% for invasion of the
common carotid artery; 33.3%, 98.8%, and 97.1% for invasion of the
internal jugular vein; and 78.2%, 89.8%, and 85.5% for invasion to the
recurrent laryngeal nerve. (AJR Am J Roentgenol.2010
Locally advanced thyroid cancer: can CT help in prediction of
extrathyroidal invasion to adjacent structures?
Seo YL, Yoon DY, Lim KJ, Cha JH, Yun EJ, Choi CS, Bae S )

36. Non thyroidal causes of decreased
radioiodine uptake
Contrast media :
Water soluable : 2- 4 wks
Fat soluble(lymphangiography) : months- year
Thyroid hormone
Iodinated drugs/foods
Heart failure /Renal failure
Prior irradiation

37. Interference for radioiodine uptake
• 1 mg of stable iodine can cause significant
reduction of the 24 hr radioiodine uptake
• 10 mg can effectively block the gland, with
98% reduction uptake.
• Iohexol contains 350mg of iodine

38. CECT BETTER AVOIDED IF
POSTOP IODINE ABLATION
THERAPY IS PLANNED

39. MRI
• Mainly for detecting extrathyroidal invasion
• Paratracheal , retrosternal extension and
nodes in deep spaces of neck are well defined.
• Advantage over CT :
- No interference with iodine uptake.
- Better tissue contrast
- Multiplane evaluation

40. MRI

41. C.FOLLOWUP/SURVEILLANCE
• THYROGLOBULIN / USG
• Yearly USGNeck recommended even if
thyroglobulin is normal

42. Elevated Thyroglobulin
• USG NECK
• I 131 WHOLE BODY SCAN
• MRI- NECK
• If everything negative, then
PET/CT

43. D.Therapeutic Purpose
• USG guided cyst aspiration/sclerosing.
• I 131 radionucleotide ablation

44. PAP CA

45. MEDULLARY CA

46. ANAPLASTIC CARCINOMA

47. RECENT ADVANCES
• ELASTOGRAPHY
• OPTICAL COHERENCE
TOMOGRAPHY/MICROSCOPY
• MR SPECTROSCOPY

48. ELASTOGRAPHY
• Elastography could be considered as an
“imaging palpation ”… technique to measure
the stiffness of tissues.
• USG elastography (SE) differentiates between
benign and malignant lesions on the basis of
their elasticity:
• Benign lesions have an elasticity similar to the
surrounding tissue, while malignant lesions
are harder than adjacent tissue.

49. 4% -1% Agar-
Gelatin Elastic
phantom
~ 100 µs
Step 1: Volumetric force
creation using
ultrasound beam focus
1D Cross-correlation
Step 3: Image
acquisition and
processing
Ultrasound beam
US
images
Uz(x,t)
Step 2: Ultra fast imaging
of the displacement
generated by ultrasounds
Texp=20 ms~ 0.3 ms
Acquisition time < 30 ms !!
Courtesy of Dr Anne Tardivon - Institut Curie - Paris
SuperSonic Elastography

50. Table1
Diagnostic performanceof conventional US and acombination of conventional US and elastography for diagnosing thyroid malignancy according to thetypeof elastography
US USE US USE US USE US USE US USE
Trimboli et al. [25] 2012 198 SE 85.0 97.0 54.0 34.0 62.0 50.0 38.0 33.0 91.0 97.0
Ragazzoni et al. [26] 2012 132 SE 70.0 85.0 92.4 83.7 85.6 84.1 80.0 69.4 87.6 92.8
Cappelli et al. [27] 2012 159 SE 80.0 ND 75.0 70.8 75.4 73.6 25.0 26.3 97.2 100
Moon et al. [19] 2012 703 SE 91.7 92.2 66.7 65.0 74.4 73.4 55.1 54.1 94.7 94.9
Unluturk et al. [28] 2012 237 SE 69.0 41.0 85.0 93.0 81.0 81.0 60.0 67.0 89.0 83.0
Veyrieres et al. [21] 2012 297 SWE 77.1 97.1 58.0 55.3 ND ND 19.7 22.5 95.0 99.3
Shweel et al. [23] 2013 66 SE 92.0 95.4 72.9 94.8 60.1 95.2 95.0 82.3 63.1 98.8
Russ et al. [24] 2013 4,550 SE 95.7 98.5 61.0 44.7 62.0 48.3 ND ND 99.7 99.8
Kim et al. [14] 2013 99 SWE 90.5 50.0 59.7 80.0 67.0 78.6 ND ND ND ND
Accuracy (%) PPV (%) NPV (%)
US, conventional ultrasonography;PPV, positivepredictivevalue;NPV, negativepredictivevalue;USE, combination of conventional ultrasonography and elastography;SE, strain
elastography;SWE,shear waveelastography;ND, not determined.
Reference Publication year Case number Type
Sensitivity (%) Specificity (%)

51. OPTICAL COHERENCE TOMOGRAPHY
• Optical coherence tomography (OCT) allows
tissue histologic-like evaluation, but without
tissue fixation or staining.
• Noncontact, non invasive microresolution
study of tissues based on principle of
Michelson interferometry
• OCM (Microscopy)is an extension of OCT and
provides high magnification resulting in
cellular imaging.

53. • Optical coherence tomography imaging during thyroid and
parathyroid surgery: a novel system of tissue identification and
differentiation to obviate tissue resection and frozen section.
• Conti de Freitas LC1, Phelan E, Liu L, Gardecki J, Namati E, Warger
WC, Tearney GJ, Randolph GW
• This pilot study demonstrated that new-generation OCT systems are
capable of recognizing and differentiating neck tissues encountered
during thyroid and parathyroid surgeries.
• Further advances in OCT miniaturization and development of sterile
intraoperative probe formats may allow OCT to offer an intraoperative
"optical biopsy" without fixation, staining, or tissue resection.
• Copyright © 2013 Wiley Periodicals, Inc.

54. MR SPECTROSCOPY
• MR spectroscopy is a sensitive method in
differentiating thyroid carcinoma from benign
follicular lesion.
• Choline peak is identified in almost all
carcinomas, with raised choline/creatine ratio
ranging from 1.6 in well differentiated carcinoma
to 9.4 in anaplastic carcinoma.
• The normal thyroid tissue and benign follicular
lesions generally demonstrate no choline peak.

55. Take Home Message
• High resolution USG neck suffice for
evaluation of thyroid nodule /intrathyroidal
malignancy
• CECT better avoided if ablation therapy
planned

56. Thyroid…...
Ode To the Thyroid
•
The thyroid is such a funny thing wrapped inside
your neck
I’m strong I’m tough I’m young and bold so
thyroid…..what the heck
It won’t stop me from doing well and living life
in full
It’s such a tiny little thing who said it had to rule
I don’t see why I feel so cold my fingers hurt like
mad
I don’t see why I feel fatigue why is it so so bad
Why is that I fall asleep at every given chance
The muscle cramps the tired legs the sickly
looking stance
I would get help for all these things but my
memory lets me down
I m going mad it’s just not fair I forgot the way to
town
My minds a fuzz my hair is thin my nails a
breaking fast
The lack of hair around my eyes gives everyone
a laugh
• Please doctor can you help me now as I really feel so
sad
You call me in and look away you think I’m going mad
The test are taken all sent off, now its time to wait
At last there is a reason something I can hate
• And hate you very much I do for months of grief and
strife
For all the days you made me bad to both my kids and
wife
You will not win this battle now as I have all the facts
But hell it’s hard to fight this thing and get myself on
track
So all of you both young and old take heed and listen
good
You can’t ignore your body’s voice even if you could
Oh so fast things slow down you don’t see what it is
Your thyroids got you by your throat yes you! Not mine,
not his.
• -------Jack frost
• THANK YOU