Use of TI-RADS system in differential diagnosis of thyroid cancer

Abstract

Aim. To evaluate the effectiveness of ultrasound classification of thyroid palpable abnormalities using TI-RADS system for thyroid cancer detection in the Chuvash Republic. 
 Methods. The study is based on the results of examining of 296 patients (study group) with thyroid palpable abnormalities. All patients from the study group had multi-parametric ultrasound imaging performed using modern methods and techniques (B-mode, color and power Doppler mapping). Based on ultrasound data received, signs of malignancy of thyroid palpable abnormalities by TI-RADS system were identified. Data from ultrasound protocols were compared with cytological and morphological findings. Fine needle biopsy was used as «gold standard» for the diagnosis of thyroid cancer. 
 Results. All patients from study group were divided according to echographic characteristics into 4 subgroups by TI-RADS scale: TI-RADS 3, TI-RADS 4a, TI-RADS 4b, TI-RADS 5. Out of the total number of patients thyroid cancer in TI-RADS 3 subgroup was determined in 14 (4.7%) cases, TI-RADS 4a - in 36 (12.2%), TI-RADS 4b - in 66 (29.1%), TI-RADS 5 - in 160 (54.0%) cases. Among patients from TI-RADS 3 subgroup papillary cancer was detected in 6.7% (11) cases, follicular cancer - in 2.5% (3); in TI-RADS 4a subgroup papillary carcinoma was detected in 61.1% of cases, follicular cancer - in 36.1%, medullary cancer - in 2.8%; in TI-RADS 4b in 76.4% of cases papillary carcinoma was detected, in 31.4% - follicular cancer and in 1.2% - medullary cancer; in TI-RADS 5 subgroup in 46.3% of cases papillary carcinoma was detected, in 46.9% - follicular cancer, in 5.6% - medullary cancer and in 1.3% - anaplastic carcinoma was detected. 
 Conclusion. Suggested TI-RADS classification makes it possible to standardize thyroid ultrasound protocol; introduction of TI-RADS classification into algorithm of early radiological diagnosis of thyroid cancer allows improving thyroid cancer diagnosis.