Presented by Int. 楊為傑

1. Management of Thyroid Nodules Detected at US: Society of Radiologists in Ultrasound Consensus Conference Statement Presented by Int. 楊為傑 Radiology 2005; 237: 794-800

2. Introduction • Goal: To determine which thyroid nodule should undergo FNA. • FNA and cytopathological examination of a thyroid nodule are usually required before surgery. • This recommendation based on nodules size and US characteristics

3. Methods and Conference • Director, codirector and 19 panelists, all whom have specialty experience in thyroid nodule evaluation and treatment. • Radiologist, Pathologist, Endocrinologist, Surgeon. • 14 articles were sent before the conference.

4. Thyroid nodules • 4-8% of adults by means of palpation. • 10-41% by US • 50% by autopsy

5. Risk of malignancy • Age: <20 or >60 • PE: firmness of the nodule, rapid growth, fixation to nearby structure, vocal cord paralysis, enlarged regional lymph nodes. • History of neck irradiation, positive family history

6. Incidence of cancer by FNA • For patients with thyroid nodules selected for FNA: 9.2%-13%, • In patient with multiple thyroid nodules: cancer rate per person was 10-13%. • 2/3 was found in largest nodules. • Incidentally found thyroid nodule: the cancer rate was the same as above.

7. Thyroid cancer • About 25000 newly diagnosed cases and 1400 died per year in United States. • Papillary thyroid cancer: 75-80%. • Follicular(10-20%), medullary(3-5%), anaplastic(1-2%). • Papillary thyroid carcinoma: 30 years survival rate95%

8. US features of Thyroid cancer • A thyroid nodule was defined as a discrete lesion within the thyroid gland that is distinguished from parenchyma • Gray-scale and Doppler US. • Size, echogenicity, composition, calcifications, halo, irregular margins, internal blood flow

9. US findings • Size doesn’t matter • Several US features increased risk of thyroid cancer

11. US features • The combination of factors improved the positive predictive rate. • Solid nodule with microcalicification 31.6% of being malignancy • Flow in central portion malignancy ↑

12. Cytopathology • With a experienced cytologist, the accuracy rate was high • Negative– Suspicious—Positive—Nondiagnostic • For positive results: false positive <1% • For suspicious results: 30-65% will be proven as cancer • Nondiagnostic rate: 15-20%. Cancer rate: 5-9%

13. Discussion • To assist physician to decide which nodule should undergo FNA. • May change • Flexibility • To diagnose and to begin treatment as early as possible. • Avoid unnecessary tests and surgery.

14. Several Questions • Diagnosis of small cancer (<1 or 2cm) improve life expectancy? • Benefits of removing papillary cancer <1cm outweigh the risk of more patient receive surgery? • If FNA and surgery ↑cost/benefit?

15. Discussion • This recommendation apply to nodule > 1cm. • US features + size

16. Consensus Statement

20. Statement • Not apply to all patient, such as history of increased risk or positive physical findings.

21. Explanations • Measurements: should take the maximum diameter. • Calcification: in solid nodule if calcification present 3 folds malignancy than non • Represent calcified psamomma bodies. • Too small to induce posterior shadowing • Tiny echogenicities calcification

22. Explanations • Composition: Solid or predominantly solid nodules have higher risk • Cystic lesion have a very low likelihood.

23. Color Doppler • Marked internal flow  risk ↑ • Differentiate solid part: tissue or clot or debris, etc. • US-guide FNA: directed toward region with visible flow.

25. Explanations • Interval growth: If the nodules grew during the serial US studies FNA is appropriate even prior FNA was benign. • No consensus on how to define substantial growth

26. Abnormal cervical lymph nodes • The presence of abnormal lymph nodes override the US features criteria. Biopsy of the node and ipsilateral thyroid nodule. • Higher risks: heterogenous echotexture, calcifications, cystic areas. • Size is less reliable than above.

28. For future • 1.How should substantial growth be defined? • 2.Other US features that might be used to prove a nodule is benign? • 3.Cost-effectiveness?

29. Thanks for your attention!