ESA-SRB-AOTA 2019

Impact of size threshold on diagnostic performance of US fine-needle aspiration for thyroid malignancy: comparison of three international guidelines (#770)

Wooyul Paik 1 , Dong Gyu Na 1
  1. Gangneung Asan Hospital, Gangneug-si, Gangwon-Do, South Korea

      Purpose

  • To evaluate the impact of size thresholds on the diagnostic performance of US FNA criteria from KSThR/KTA, ATA, and ACR guidelines in the diagnosis of thyroid malignancy

       Patient 

  • Jan 2010 ~ May 2011 : 2000 nodules (≥ 1 cm) : Benign (1546)  Malignancy (454) 

         Result

  • Concordance rate and correlation of classified risk categories of  nodules and comparison of simulated diagnostic performance with 4 size criteria thresholds for FNA in 3 guidelines 
  • Concordance rate and Correlation coefficients of risk categories

          KSThR/KTA vs. ATA     87.0%    0.937,  p <0.001

           KSThR/KTA vs. ACR     78.0%    0.889,  p <0.001

          ATA vs. ACR  84.0%   0.912,  p <0.001

        

Size Threshold

Criteria

SENS

SPEC

PPV    

NPV

ACC

Unnecessary

FNA Rate

Criteria 1

　

　

　

　

　

　

KSThR/ATA

94.5

26.4

27.4

94.2

41.9

56.9**

ATA

93.8

27.9

27.7

93.9

42.9

55.7**

ACR

93.4

37.3

30.4

95.1

50.1

48.5**

Criteria 2

　

　

　

　

　

　

KSThR/ATA

90.5

43.3

31.9

94.0

54.1

43.8**

ATA

90.5

41.7

31.3

93.8

52.8

45.1**

ACR

90.3

48.4

34.0

94.5

58.0

39.9**

Criteria 3

　

　

　

　

　

　

KSThR/ATA

  76.9*

55.2

33.5

89.0

60.1

34.7**

ATA

  78.9*

53.2

33.1

89.5

59.0

36.2**

ACR

  75.6*

61.4

36.5

89.5

64.7

29.8**

Criteria 4

　

　

　

　

　

　

KSThR/ATA

  75.6*

63.7

37.9

89.9

66.4

28.1**

ATA

  77.5*

62.2

37.6

90.4

65.7

29.2**

ACR

  74.7*

67.3

40.2

90.1

69.0

25.3**

  • Size Threshold

    Criteria

    SENS

    SPEC

    PPV    

    NPV

    ACC

    Unnecessary

    FNA Rate

    Criteria 1

    ~1.1

    ~10.9

    ~3.0

    ~1.2

    ~8.2

    ~8.4

    Criteria 2

    ~0.2

    ~6.7

    ~2.7

    ~0.7

    ~5.2

    ~5.2

    Criteria 3

    ~3.3

    ~8.2

    ~3.4

    ~0.5

    ~5.7

    ~6.4

    Criteria 4

    ~2.8

    ~5.1

    ~2.6

    ~0.5

    ~3.3

    ~1.1
  • Conclusion
  • The difference of diagnostic performance between KSThR/KTA or ATA and ACR guidelines is mainly related to the different size threshold of FNA.
  • 2cm threshold for low suspicion nodules will decrease the unnecessary FNA rate more than 10% while maintaining the high sensitivity (> 90%) in both KTA/KSThR and ATA guidelines.