The gray zone of thyroid nodules: Using a nomogram to provide malignancy risk assessment and guide patient management

Integrated intraoperative predictive model for malignancy risk assessment of thyroid nodules with atypia of undetermined significance cytology

Management of thyroid nodules with atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) cytology is challenging because of uncertain malignancy risk. Intraoperative frozen section pathology provides real-time diagnosis for AUS/FLUS nodules undergoing surgery, but its accuracy is limited. This study aimed to develop an integrated predictive model combining clinical, ultrasound and IOFS features to improve intraoperative malignancy risk assessment. A retrospective cohort study was conducted on patients with AUS/FLUS cytology and negative BRAFV600E mutation who underwent thyroid surgery. The cohort was randomly divided into training and validation sets. Clinical, ultrasound, and pathological features were extracted for analysis. Three models were developed: an IOFS model with IOFS results as sole predictor, a clinical model integrating clinical and ultrasound features, and an integrated model combining all features. Model performance was evaluated using comprehensive metrics in both sets. The superior model was visualized as a nomogram. Among 531 included patients, the integrated model demonstrated superior diagnostic ability, predictive performance, calibration, and clinical utility compared to other models. It exhibited AUC values of 0.92 in the training set and 0.95 in the validation set. The nomogram provides a practical tool for estimating malignancy probability intraoperatively. This study developed an innovative integrated predictive model for intraoperative malignancy risk assessment of AUS/FLUS nodules. By combining clinical, ultrasound, and IOFS features, the model enhances IOFS diagnostic sensitivity, providing a reliable decision-support tool for optimizing surgical strategies.

The Role of "Critical" Ultrasound Reassessment in the Decision-Making of Bethesda III Thyroid Nodules

Background and Objectives: Bethesda III (BIII) thyroid nodules have an expected malignancy rate of 5-15%. Our purpose was to assess which US criteria are most associated with cancer risk, and the value of critical ultrasound (US) reassessment. Methods: From 2018 to 2022, 298 BIII nodules were enrolled for thyroidectomy (79 malignancies). We evaluated ultrasonographic data: hechogenicity, intralesional vascularization, spiculated margins, micro-calcifications, "taller than wide" shape, extra-thyroidal growth, size increase, as well as their association with histology. We also evaluated if the ultrasound reassessment modified the strategy. Results: Spiculated margins and microcalcification were significantly correlated with malignancy risk. Spiculated margins showed a specificity of 0.95 IC95% (0.93-0.98); sensitivity 0.70 IC95% (0.59-0.80). Microcalcifications showed a sensitivity of 0.87 CI95% (0.80-0.94); specificity 0.75 CI95% (0.72-0.83). The presence of these signs readdressed the strategy in 76/79 cases Then, the indication for surgery was appropriate in 75% of cases. Conclusions: Microcalcifications and spiculated margins should be routinely sought during a final ultrasound reassessment in BIII nodules. These signs allowed for a modification of the strategy in favor of surgery in 96% of the cases that were not otherwise referred to surgery. The importance of integrating ultrasound and cytology in the evaluation of BIII thyroid nodules is confirmed. Reassessment with ultrasound of BIII nodules allowed for a redirection of the surgical choice.

Application of machine learning methods to guide patient management by predicting the risk of malignancy of Bethesda III-V thyroid nodules

OBJECTIVE

Indeterminate thyroid nodules (ITN) are common and often lead to (sometimes unnecessary) diagnostic surgery. We aimed to evaluate the performance of two machine learning methods (ML), based on routinely available features to predict the risk of malignancy (RM) of ITN.

DESIGN

Multi-centric diagnostic retrospective cohort study conducted between 2010 and 2020.

METHODS

Adult patients who underwent surgery for at least one Bethesda III-V thyroid nodule (TN) with fully available medical records were included. Of the 7917 records reviewed, eligibility criteria were met in 1288 patients with 1335 TN. Patients were divided into training (940 TN) and validation cohort (395 TN). The diagnostic performance of a multivariate logistic regression model (LR) and its nomogram, and a random forest model (RF) in predicting the nature and RM of a TN were evaluated. All available clinical, biological, ultrasound, and cytological data of the patients were collected and used to construct the two algorithms.

RESULTS

There were 253 (19%), 693 (52%), and 389 (29%) TN classified as Bethesda III, IV, and V, respectively, with an overall RM of 35%. Both cohorts were well-balanced for baseline characteristics. Both models were validated on the validation cohort, with performances in terms of specificity, sensitivity, positive predictive value, negative predictive value, and area under the receiver operating characteristic curve of 90%, 57.3%, 73.4%, 81.4%, 84% (CI95%: 78.5%-89.5%) for the LR model, and 87.6%, 54.7%, 68.1%, 80%, 82.6% (CI95%: 77.4%-87.9%) for the RF model, respectively.

CONCLUSIONS

Our ML models performed well in predicting the nature of Bethesda III-V TN. In addition, our freely available online nomogram helped to refine the RM, identifying low-risk TN that may benefit from surveillance in up to a third of ITN, and thus may reduce the number of unnecessary surgeries.

The diagnostic value of a nomogram based on multimodal ultrasonography for thyroid-nodule differentiation: A multicenter study

Objective

To establish and verify a nomogram based on multimodal ultrasonography (US) for the assessment of the malignancy risk of thyroid nodules and to explore its value in distinguishing benign from malignant thyroid nodules.

Methods

From September 2020 to December 2021, the data of 447 individuals with thyroid nodules were retrieved from the multicenter database of medical images of the National Health Commission’s Capacity Building and Continuing Education Center, which includes data from more than 20 hospitals. All patients underwent contrast-enhanced US (CEUS) and elastography before surgery or fine needle aspiration. The training set consisted of three hundred datasets from the multicenter database (excluding Zhejiang Cancer Hospital), and the external validation set consisted of 147 datasets from Zhejiang Cancer Hospital. As per the pathological results, the training set was separated into benign and malignant groups. The characteristics of the lesions in the two groups were analyzed and compared using conventional US, CEUS, and elastography score. Using multivariate logistic regression to screen independent predictive risk indicators, then a nomogram for risk assessment of malignant thyroid nodules was created. The diagnostic performance of the nomogram was assessed utilizing calibration curves and receiver operating characteristic (ROC) from the training and validation cohorts. The nomogram and The American College of Radiology Thyroid Imaging, Reporting and Data System were assessed clinically using decision curve analysis (DCA).

Results

Multivariate regression showed that irregular shape, elastography score (≥ 3), lack of ring enhancement, and unclear margin after enhancement were independent predictors of malignancy. During the training (area under the ROC [AUC]: 0.936; 95% confidence interval [CI]: 0.902–0.961) and validation (AUC: 0.902; 95% CI: 0.842–0.945) sets, the multimodal US nomogram with these four variables demonstrated good calibration and discrimination. The DCA results confirmed the good clinical applicability of the multimodal US nomogram for predicting thyroid cancer.

Conclusions

As a preoperative prediction tool, our multimodal US-based nomogram showed good ability to distinguish benign from malignant thyroid nodules.

CYTOLOGICAL DIAGNOSIS OF FINE-NEEDLE PUNCTURE BIOPSIES OF THE THYROIDGLAND IN UKRAINE: COMPARIS ON WITH INTERNATIONAL PRACTICE

Thyroid cancer is one of the few cancers diagnosed by cytological examination of thin nodule puncture biopsies. To achieve standardization of diagnostic terminology, morphological criteria and risk of malignancy in the whole world, the 6-level Bethesda system is used. The work aimed to analyze the results of cytological examination of fine-needle aspiration puncture biopsies (TAPBs) of thyroid nodules according to the international Bethesda system for the last three years and compare them with the world practice. As a result, 5687 surveys were conducted, where the proportion of women was 87.9% and of men 12.1%. Of all the cases, the most extensive cytological findings were of class II (benign formation) - 3061 studies (57%). The number of cases interpreted as class III was within the reference values, i.e. 8.2%. The fourth class accounted for 8.2%, the fifth for 3.5%, and the sixth for 5.0%. In total, these three classes account for 17.2%. Our analysis compared the reference values and data from other laboratories revealed comparable results. The analysis of the structure of the results of cytological investigations according to Bethesda revealed a high rate of the first class (non-informative), which indicates the need for more accurate interaction between clinical physicists and cytologists.