05/03/2013

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Thyr

oid

Can

cer

-SP

ECT

/CT

“To

D

o /

Not

to

”

HK MohanDepartment of Nuclear Medicine

Guys & St Thomas’ Hospitals, London

SPECT/CT in Thyroid cancerTo do / not to?

48 year old – PT3 N1bMO

• TSH = 88• Tg = 129• Pre therapy 185MBq I131 study

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48 year old – PT3 N1bMO• Post Surgery – 5.5 Gbq I1316 months later• TSH = 113• Tg = 1.1

Aided surgery

Liver uptake - Gall bladder. No MRI required

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26 year old male – PT2 N0Mx

• TSH = 48• Tg = 12.9• 3.7 Gbq I131• Post Therapy imaging

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26 year old male – PT2 N0Mx

6 months later• TSH = 53• Tg = <0.2

No need for further MRI / US post firstablation

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58 year old male – PT3 N1bM1

• TSH = 62• Tg = 152• 3.7GBq I131 – Post Therapy imaging

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58 year old male – PT3 N1bM1

6 months later pre second ablation• TSH = 77• Tg = 22• 5.5 GBq I131

Revealed destructive nature promptingfurther investigation and EBRT

32 year old female – PT2 N0MO

• TSH = 52• Tg = 24• 5.5 Gbq I131- Post therapy study

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32 year old female – PT2 N0MO

Prior to 4th ablation• TSH = 44• Tg = 1.8• 5.5 Gbq I131

Aided decision re surgery and monitoring response to therapy

41 year old female– PT3 N0Mx

• TSH = 88• Tg = 152• 3.7 GBq I131 study

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41 year old female– PT3 N0MxRevealed I131 negative disease and directed further management

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Guys’ Experience

• 67 patients• 5 year follow-up• 57 – I131 avid disease• 10 – Non I131 avid disease

Reporter confidence

Probable Definite

Thyroid remnant 0 34

Lymph nodes 1 10

Probable Definite

Thyroidremnant

5 23

Lymph nodes 12 5

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Staging change -14/57 (25%)Downstaging – 10 patientsNeck8 definite LN Thyroid remnant

Thorax1 lung Physiologic breast uptake1Node Oesophageal

Upstaging - 4 patientsNeck3 thyroid remnant 3 LN

Thorax1 oesophageal I node

Literature reviewN = 520 Management Impact due to change in staging

163 / 520 (31%)

Avram et al, 2010 48 28 / 48 (58%)

Spanu et al, 2009 117 33 / 117 (35.6%)

Schmidt et al. 2009 57 20 / 57 (35%)

Grewal et al 2010 148 29 / 148 (20%)

Chen L et al 2009 23 8 / 23 (35%)

S. Kohlfuerst et al 2009 41 17 / 41 (24.4%)

K Tharp et al 2004 61 22 / 61 (27%)

J Ruf et al 2004 25 6 / 25 (24%)

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Clinical ImpactDown staging

• Patient reassurance

• Efficient use of facilitiesAvoiding US / CT / MRI

• Reduced cost

Upstaging• Targetted surgery / EBRT

• Tailoring I131 dose• Reduced therapies

Reduced side effects

• Reduced recurrence rates

Improved survival

Significant incidental findings

Does is impact survival?

• >90% 10 yr survival• 43 % of all relapses in 1st year • 23 % years 2-5 • 9 % > 10 years

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PrognosisCR 10YS %

• Lung only 131 I +ve 46% 62 • Lung only 131 I -ve 11 • Lung + other (bone) 10

Impact on Survival

• Early days• 3-5 year followup currently available• Lymphnode metastases - Still has >90% 10 year

survival rate• Distant metastases 50 - 60% 10 year survival

rate • Non I131 avid disease - Limited treatment

options

2626

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Current indications for SPECT/CT

• High risk patients. • Iodine uptake in neck which is disproportionate

to initial disease and staging.• Any abnormal uptake outside neck for accurate

localisation and characterisation.• Patients with raised thyroglobulin with negative

iodine whole body scintigraphy.

Imaging protocol• Imaged 3-5 days post I131 administration

• WBSAnterior and Posterior whole body images Scanning speed - 3-8mm/sec

• SPECTHEHR collimatorMatrix size - 64 x 64. 64 projectionsProcessing – FBP and OSEM

• CT Voltage - 120 KV, Tube current - 100mAs/sliceSlice thickness -1.5mmCT dose exposure – 3 mSv

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Thanks for listening!!!

BTA / RCP - Guidelines for management of thyroid cancer, 2nd ed, 2007EANM - Guidelines for radioiodine therapy of differentiated thyroidcancer 2008