Thyroid nodules ≤ 5 mm on ultrasonography: are they "leave me alone" lesions?

Thyroid imaging reporting and data system (TIRADS) for ultrasound features of nodules: multicentric retrospective study in China

PURPOSE

To establish a practical and simplified Chinese thyroid imaging reporting and data system (C-TIRADS) based on the Chinese patient database.

METHODS

A total of 2141 thyroid nodules that were neither cystic nor spongy were used in the current study. These specimens were derived from 2141 patients in 131 alliance hospitals of the Chinese Artificial Intelligence Alliance for Thyroid and Breast Ultrasound. The ultrasound features, including location, orientation, margin, halo, composition, echogenicity, echotexture, echogenic foci and posterior features were assessed. Univariate and multivariate analyses were performed to investigate the association between ultrasound features and malignancy. The regression equation, the weighting, and the counting methods were used to determine the malignant risk of the thyroid nodules. The areas under the receiver operating characteristic curve (Az values) were calculated.

RESULTS

Of the 2141 thyroid nodules, 1572 were benign, 565 were malignant, and 4 were borderline. Vertical orientation, ill-defined, or irregular margin (including extrathyroidal extension), microcalcifications, solid, and markedly hypoechoic were positively associated with malignancy, while comet-tail artifacts were negatively associated with malignancy. The logistic regression equation yielded the highest Az value of 0.913, which was significantly higher than that obtained using the weighting method (0.893) and the counting method (0.890); however, no significant difference was found between the latter two. The C-TIRADS, based on the counting method, was designed following the principle of balancing the diagnostic performance and sensitivity of the risk stratification with the ease of use.

CONCLUSIONS

A relatively simple C-TIRADS was established using the counting value of positive and negative ultrasound features.

Explore the Diagnostic Efficiency of Chinese Thyroid Imaging Reporting and Data Systems by Comparing With the Other Four Systems (ACR TI-RADS, Kwak-TIRADS, KSThR-TIRADS, and EU-TIRADS): A Single-Center Study

PURPOSE

To explore the characteristics of C-TIRADS by comparing it with ACR-TIRADS, Kwak-TIRADS, KSThR-TIRADS and EU-TIRADS.

METHODS

A total of 1096 nodules were collected from 884 patients undergoing thyroidectomy in our center between May 2018 and December 2020. Divided the nodules into two groups: ">10mm" and "≤10mm". Ultrasound characteristics of each nodule were observed and recorded by 2 doctors, then classified based on ACR-TIRADS, Kwak-TIRADS, KSThR-TIRADS, EU-TIRADS, and C-TIRADS.

RESULTS

A total of 682 benign nodules cases (62.23%) and 414 malignant nodules cases (37.77%) were identified. The ICC value of each guideline was:0.937(ACR-TIRADS), 0.858(EU-IRADS), 0.811(Kwak-TIRADS), 0.835(KTA/KSThR-TIRADS) and 0.854(C-TIRADS). The nodule malignancy rates in the groups(Kwak-TIRADS 4B, C-TIRADS 4B、4C) of two sizes were significantly different (all p<0.05). There was no statistical difference in the other grades of two sizes (all p>0.05). Unnecessary biopsy rates were the lowest in C-TIRADS (49.02% p<0.001). Furthermore, Kwak-TIRADS had the highest sensitivity and NPV (89.9%, 91.0%, all p<0.05), while C-TIRADS had the highest specificity and PPV (82.3%, 69.2%, all p<0.05). C-TIRADS and Kwak-TIRADS had the highest accuracy (76.0%, 72.5%, P=0.071). The AUCs of the 5 guidelines were C-TIRADS(0.816, P<0.05), Kwak-TIRADS(0.789, P<0.05) KTA/KSThR-TIRADS and ACR-TIRADS(0.773, 0.763, P=0.305), EU-TIRADS(0.734, P<0.05). The AUCs of the five guidelines were not statistically different between "nodules>10mm" and "nodules ≤ 10mm" (all P>0.05).

CONCLUSIONS

All five guides showed excellent interobserver agreement. C-TIRADS was slightly efficient than Kwak-IRADS, KTA/KSThR-TIRADS and ACR-TIRADS, and had greater advantages than EU-TIRADS. The diagnostic abilities of the five guidelines for "nodules ≤ 10mm" were not inferior to that of "nodules> 10mm". C-TIRADS is simple and easy to implement and can provide effective thyroid tumor risk stratification for thyroid nodule diagnosis, especially in China.

The rising trend in papillary thyroid carcinoma. True increase or over diagnosis?

OBJECTIVES

To assess the changes in parameters of thyroid carcinoma, particularly papillary type, in the era of widespread use of sensitive diagnostic methods. We aim to investigate whether the increased frequency of thyroid cancer is true or resulted from over diagnosis. Methods: We conducted a retrospective study of 313 cases of thyroid carcinoma diagnosed at Jordan University Hospital and King Hussein Cancer Center from 2007-2015. Papillary carcinoma accounted for 290 (92.7%) of all cases. Cases were sub classified according to demographic features, histological type, size, stage, and other variables. For comparison of data, cases were subdivided into 2 study periods: Group I included patients diagnosed in the period 2007-2010, and Group II in the period 2011-2015. Results: The frequency of thyroid carcinoma has increased across the study period. Papillary carcinoma was the major type accounting for this increase. Papillary micro carcinomas ≤1cm accounted for 34.8% of cases of PTC. Most cases (52.4%) of papillary thyroid carcinoma (PTC) were localized stage tumors. Group II of the study witnessed a more than doubled number of cases of PTC compared to group I, with increased frequency of tumors of all sizes as well as tumors of both localized and regional stages. Conclusions: Our observed trend cannot be totally explained by over diagnosis and increased diagnostic scrutiny. This increase could be of true nature and cannot be explained by single cause.

Contrastive study of two screening criteria for active surveillance in patients with low-risk papillary thyroid microcarcinoma: a retrospective analysis of 1001 patients

Screening out patients who do not require immediate surgery is a growing trend in the field of thyroid research. In this study, we retrospectively compared the application of two surveillance selection criteria in 1001 patients who had undergone surgical treatment of papillary thyroid microcarcinoma (PTMC): low-risk PTMC characteristics defined by Kuma Hospital and CATO consensus on PTMC management of active surveillance. Treatment outcomes were compared between groups. We then analyzed the prognostic indicators of patients who could be managed by surveillance. A total of 724 patients met Kuma screening criteria and 135 met CATO screening criteria. The Kuma low-risk group had a lower incidence of multifocal lesions and CLNM than Kuma high-risk group. We also found more obvious differences in multifocal lesions, CLNM and extrathyroidal extension when evaluating the CATO low-risk criteria in the same manner. On the other hand, patients in the CATO low-risk group had a lower disease progression rate and longer disease-free survival than those in CATO high-risk group. There was no significant difference in prognosis between the Kuma low-risk group and Kuma high-risk group. Our logistic regression analysis showed that a preoperative ultrasound size of >5 mm, male sex, younger age, and malignant lesions without concurrent benign nodules could be predictors of CLNM. In conclusion, patients classified in CATO low-risk criteria had lower proportion of clinicopathological risk factors than the ones in Kuma low-risk criteria. We also found more risk factors may not be suitable for surveillance, such as tumors without concurrent benign nodules.

Follow-up ultrasound may be enough for thyroid nodules from 5 mm to 1 cm in size

We investigated whether follow-up ultrasound (US) is enough for thyroid nodules 5-10 mm, and whether 3 years of interval between the initial US and next US is appropriate. This retrospective study was approved by the Institutional Review Board, and the need to obtain informed consent was waived. The study included 447 thyroid nodules 5-10 mm from 378 patients who underwent initial thyroid US, and underwent 3 years or more of follow-up US. The presence and characteristics of malignancy detected on follow-up were reviewed. Maximal diameters of each nodule at the initial and last US were measured. Univariate and multivariate analysis were used to assess association with nodule growth 3 mm or larger. Seven malignancies (1.6 %, 7 of 447) were detected on a mean 70.6 ± 20.3 months (range 36-104 months). Only one had growth 3 mm or larger, and all malignancies did not have extensive extrathyroidal extension, lateral lymph nodes, or distant metastasis. 6.0 % (27 of 447) of nodules had growth 3 mm or larger. Nodules in older patients were less likely to grow, and benign-looking nodules were more likely to grow. Longer follow-up time 6 years or more was not associated with growth, and no cancers were detected during the long follow-up time. Immediate US-FNA for thyroid nodules 5-10 mm are discouraged, unless suspicious metastatic lymph nodes are present. Also, a follow-up US 3 years after the initial US may be enough for these nodules.

Sonographic Detection of Extracapsular Extension in Papillary Thyroid Cancer

OBJECTIVES

To identify and evaluate sonographic features suggestive of extracapsular extension in papillary thyroid cancer.

METHODS

Three board-certified radiologists blinded to the final pathologic tumor stage reviewed sonograms of pathologically proven cases of papillary thyroid cancer for the presence of extracapsular extension. The radiologists evaluated the following features: capsular abutment, bulging of the normal thyroid contour, loss of the echogenic capsule, and vascularity extending beyond the capsule.

RESULTS

A total of 129 cases of pathologically proven thyroid cancer were identified. Of these, 51 were excluded because of lack of preoperative sonography, and 16 were excluded because of pathologic findings showing anaplastic carcinoma, follicular carcinoma, or microcarcinoma (<10 mm). The final analysis group consisted of 62 patients with papillary thyroid carcinoma, 16 of whom had pathologically proven extracapsular extension. The presence of capsular abutment had 100% sensitivity for detection of extracapsular extension. Conversely, lack of capsular abutment had a 100% negative predictive value (NPV) for excluding extracapsular extension. Contour bulging had 88% sensitivity for detection of extracapsular extension and when absent had an 87% NPV. Loss of the echogenic capsule was the best predictor of the presence of extracapsular extension, with an odds ratio of 10.23 (P = .034). This sonographic finding had 75% sensitivity, 65% specificity, and an 88% NPV. Vascularity beyond the capsule had 89% specificity but sensitivity of only 25%.

CONCLUSIONS

Sonographic features of capsular abutment, contour bulging, and loss of the echogenic thyroid capsule have excellent predictive value for excluding or detecting extracapsular extension and may help in biopsy selection, surgical planning, and treatment of patients with papillary thyroid cancer.