TIRADS is a practical system for stratifying thyroid nodule malignancy risk in clinical practice. A study of 346 nodules found substantial inter-observer agreement for TIRADS categorization. TIRADS categories 5 and 4c had high positive predictive value for malignancy, while reassigning some 4a nodules to category 3 improved specificity. Thus, TIRADS provides a simple method for ultrasound assessment and risk stratification of thyroid nodules.

1. IS TIRADS A PRACTICAL AND
ACCURATE
SYSTEM FOR USE IN DAILY
CLINICAL PRACTICE?
Presented by Dr Roshan Valentine
PG Resident
St Johns Medical College Bangalore
AUTHORS:
Anuradha Chandramohan,
Abhishek Khurana, B T
Pushpa, Marie Therese
Manipadam1, Dukhabandhu
Naik2,
Nihal Thomas2, Deepak
Abraham3, Mazhuvanchary
Jacob Paul3, CMC Vellore

2. INTRODUCTION
• 12% of adult Asian population have a palpable nodule
• 80% among children in iodine-deficient parts of India.
• Incidence of thyroid cancer is low.
• Ultrasound is a widely accepted imaging modality for the initial
assessment
• Thyroid Imaging Reporting and Data System (TIRADS) described by
Kwak et al.[15] is a relatively simple system which can be easily
adopted

3. OBJECTIVE
To assess
• Positive predictive value
• Inter-observer variability of TIRADS

4. MATERIALS AND METHODS
STUDY POPULATION
• IERB Review
• Dept of radiology at CMC vellore
• Jan 2012 – nov 2012
• Estimated sample size for assessing inter-reader reliability – 250
• 346 nodules of 307 pts
INCLUSION CRITERIA
• Solitary nodule and nodules in MNG > 1cm
• FNAC – benign/malignant lesion
• Undergone Surgery -FNAC yielded suspicious for malignancy,
indeterminate or inadequate sampling

5. MATERIALS AND METHODS
THYROID ULTRASOUND
• ACUSON S2000 AND ACUSON ANTARES Siemens
• 7-11Mhz probe
• 2 radiologists with 8 years experience
• Reviewed by a 3rd radiologist (3 yrs experience)
• Features assessed for :
1)Composition: solid cystic mixed
2)Echogenicity
3)margins: well defined +/- halo sigin , microlobulated , ill-defined , irregular
4)Calcification :micro/macro
5) Shape : round/t>w or oval

10. MATERIALS AND METHODS
THYROID ULTRASOUND
Features suggesting malignancy :
• Hypoechoic or markedly hypoechoic
• Irregular/spiculated
• Microlobulated
• Ill defined/fuzzy margins
• Microcalcifications
• Round shape

12. MATERIALS AND METHODS
TIRADS CATEGORISATION
• Cat 2: completely cystic , comet tail artefacts or spongiform
• Cat 3: Solid, oval, well-defined, isoechoic nodules
• Cat 4 a, b and c

13. THYROID FNAC
• FNAC b/w 12h to 2 days post USG
• By Surgeon and radiologist
• 2-3 aspirations by 23g needle attached to 5cc syringe
• Cytology technician to confirm the adequacy of the specimen
• BETHESDA system by cytopathologists for classification
• Class I: inadequate
• Class II : benign
• Class III: atypical or follicular cells of indeterminate significance
• Class IV: follicular neoplasm
• Class V: suspicious for malignancy
• Class VI : Malignant

14. THYROID FNAC
TIRADS≤3 +
non diag
FN/HPE+not
planned for Sx
Follow for 1
year with USG
every 6mnth
No change in
nodule
BENIGN

15. STATISTICAL ANALYSIS
• SPSS analytics 16.0 software
• Receiver operating characteristic (ROC) curve for TIRADS efficacy
• Inter-rater reliability was measured using the quadratic weighted
kappa statistics,

16. RESULTS
• Total of 272 nodules : 154 benign ; 118 malignant
• Malignancy : M>F
• Among malignant nodules , males were older than females

17. RESULTS

18. RESULTS

19. RESULTS
Diagnostic performance of TIRADS on considering
Sn(%) Sp(%) PPV(%) NPV(%) Accuracy
(%)
Benign: 2&3
Malignant :
4a,4b,4c & 5
72 68.8 63.9 76.2 70.2
Benign 2,3 & 4a
Malignant : 4b,4c
& 5
60.2 85.1 75.5 73.6 74.2

20. RESULTS
INTER-OBSERVER AGREEMENT
• Overall substantial agreement for assigning TIRADS category
• poor agreement for assigning TIRADS categories 4a and 4b

23. DISCUSSION
• Several classification system to stratify thyroid malignancy
Risk – complex
• The classification by Kwak et al is simple and similar to BIRADS and
familiar to most radiologists – hence used
• Study by Kim et al reported the USG suspicious features malignancy

24. DISCUSSION

25. DISCUSSION
• PPV and specificity improved when TIRADs4a → 3.
• Thus its better to follow up 4a Pts than subjecting them to
surgery

26. LIMITATIONS
• No prior training for examiners
• Referral centre – hence most of the lesions included were
malignant(selection bias)
• 34/112 malignant nodules were follicular variant of papillary
cancers – benign appearance.
• TB thyroid – rare and can mimic malignancy
• False positive and false negative of cytology results
• USG – guided FNAC in only 30% , rest were blind FNAC by surgeons

27. CONCLUSION
• PPV for malignancy was high for TIRADS category 5 and 4c
nodules
• Reassigning TIRADS 4a →3 will improve PPV and specificity.
• Overall agreement between observers for assigning TIRADS
category was substantial
• Thus, TIRADS is a simple and practical method of assessing
thyroid nodules and can be used in practice.

28. TIRADS
TIRADS 1 - normal thyroid gland
TIRADS 2 - benign lesions
TIRADS 3 - probably benign lesions
TIRADS 4 - suspicious lesions (subclassified as 4a, 4b and 4c with
increasing risk of malignancy)
TIRADS 5 - probably malignant lesions (more than 80% risk of
malignancy)
TIRADS 6 - biopsy proven malignancy