Endocrine Abstracts

Objective: We investigated the clinical usefulness of thyroid blood flow measurement by colour-flow Doppler ultrasonography in predicting relapse of Graves’ disease (GD).

Patients and methods: In 30 euthyroid GD patients, (eight males and 23 females), aged 17–68 years (mean 43.8±12.8), after at least 1 year of treatment with anti-thyroid drug (ATD) and just before its withdrawal, we evaluate with colour-flow Doppler ultrasonography the colour-flow Doppler mapping (the amount of flow was classified on four point scale, 0–3) and we calculate, in pulsed Doppler mode, the peak systolic velocity in the inferior thyroid artery (ITA–PSV). All ultrasound examinations were performed by the same endocrinologist expert in thyroid ultrasound using a duplex Doppler apparatus (Logic Scan 64, B-Side Medical System) with an 8 MHz linear array probe. Clinical data was collected and measurements of TSH, serum free thyroxine, and TSH receptor antibodies were performed. GD relapse was defined as an increase in the serum level of FT₄ to above the normal upper range and suppression of serum TSH in 18 months after removal of ATD. Mann–Whitney U test and Fisher’s exact test were used for statistical analysis. The sensitivity and specificity were calculated using a 2×2 table.

Results: In relapse group (n=14, 47%) ITA–PSV was significantly higher than in the non-relapse group (n=16), (48.5±17.7 cm/s vs 32.6±9.5 cm/s, P=0.01). For prediction of GD relapse, the best cut-off value was 35 cm/s for ITA–PSV. Sensitivity was 71%, specificity 87%, positive predictive value 83%, and negative predictive value 78%. All patients with grade 3 in colour-flow Doppler mapping (n=3) had an early relapse of GD (before the first 6 months).

Conclusions: Colour-flow Doppler mapping study and measurement of ITA/PSV in euthyroid GD patients immediately before withdrawal of ATD may assist in the prediction of GD relapse.