COMPARATIVE ANALYSIS OF THE BTA U SCORE SYSTEM AND THE TIRADS FOR ASSESSING THYROID NODULES
By John Rainford, Sheffield Teaching Hospitals NHS Trust
Introduction:
Ultrasound is a key diagnostic tool in evaluating the risk of malignancy in thyroid nodules. Multiple scoring systems exist, including the BTA- U and TiRADS. Little is known about the difference in scoring and reproducibility between the scoring systems.
Aim of investigation:
This study compares BTA U score and TiRADS, focusing on diagnostic accuracy for identifying malignancy.
Methods:
A retrospective population of consecutive patients who had ultrasound and FNA from 2017 - 2019 was blindly reviewed by a single experienced specialist sonographer. Each case was re-scored the nodules using both U Score and TiRADS after a 6-month washout period. Diagnostic accuracy for each system was assessed with sensitivity, specificity, negative and positive predictive values from the 2x2 contingency table.
Results:
307 patients with thyroid nodules were included, of which 113 patients had thyroid malignancy on FNA and surgery. TiRADS had 97.9% sensitivity, 25.4% specificity, 82.6% PPV and 77.0% NPV. U score had 99.86% sensitivity, 8.1% specificity, 70.45% PPV and 77.0% NPV.
Discussion:
TiRADS and U score have similarly high sensitivity, but with lower specificity. TiRADS had statistically significantly higher specificity (p <0.001). Both systems show how low false negative results from the study population. BTA U score shows higher numbers of false positives than TiRADS. Inter-rater agreement for both systems is in progress.
Conclusions:
Both systems show high sensitivity for malignancy, albeit with relatively low positive predictive values.
Acknowledgements:
The author wants to thank the colleagues who have contributed to the forthcoming inter-rater component of this study.