RADIOLOGICAL–PATHOLOGICAL DIAGNOSTIC RATE OF THE BRITISH THYROID ASSOCIATION ULTRASOUND CLASSIFICATION OF THYROID NODULES AT NMUH

New guidelines were published by the British Thyroid Association on the Management of Thyroid Cancer in February 2014. The guidelines recommend the U scoring system for assessing risk of malignancy of thyroid nodules on ultrasound and guiding fine needle aspiration cytology (FNAC). We undertook a 2-cycles audit at North Middlesex University Hospital between March 2020 to January 2022 to ascertain whether the new guidelines were being followed. BACKGROUND Primary objective: • Assess diagnostic rate of FNAs done at NMUH Secondary objectives: • Ascertain whether BTA U classification was used to score thyroid nodules. • Assess average waiting time between requesting and performing the FNA. • Predicting difference in accuracy of BTA used by radiologists and sonographers.

Methods:We performed a closed loop audit on the use of BTA-U classification of thyroid scans and the diagnostic rates of FNA cytology based on the U classification, after the results of the first cycle and recommendations to use BTA-U classifications, we performed the 2nd cycle which resulted in wider use of U-classification and increased diagnostic rates of FNA at the hospital. -Population sample This audit looked at patients who attended the North Middlesex Hospital (NMH) radiology department for FNAC between March 2020 to January 2022. Number of patients recruited for audit = 136 Number of thyroid scans = 136 + 9 (More than one nodule and FNA) Ave age = 55yrs Age range = 21-90 yrs

Results• Diagnostic rate of the FNAC is 83.3% which is above the average 70% success rates agreed by RCR • Average waiting time between request date and study completion was 5.4 weeks. • 43 scans of the sample were downgraded 18 of which were done by sonographers while 5 were done by radiology consultants while the rest were obtained externally. • U classification is used in 95.1% of the scans. • Thy1 = 15 (16.6%) • Thy2 = 34 (37.7%) • Thy3a = 22 (24.4%) • Thy3f = 10 (11.11%) • Thy4 = 4 (1 medullary ca, 1 papillary ca) (4.4%) • Thy5 = 5 (4 papillary ca) (5.5%)

CONCLUSION AND RECOMMENDATIONS - Given the high diagnostic rates of the BTA-U classification in diagnosing non-benign nodules in addition to the relatively long waiting times between the thyroid scan initially performed and the FNA done, it’s recommended to establish a one-stop clinic for FNAC led by consultant radiologist to help minimising the waiting time and early diagnosing. - Workshops done by radiology consultant to train sonographers performing thyroid scans. - Perform 3 rd cycle of the audit to ensure adherence to guidelines.

ACKNOWLEDGEMENT Authors acknowledge Dr Alaa Jaly, Radiology Consultant at North Middlesex University Hospital for her support and supervision during the time the audit was being carried out.