ObjectiveTo establish a prediction model for ipsilateral cervical lateral lymph node metastasis (LLNM) in stages T1–T2 unilateral papillary thyroid carcinoma (PTC) and to verify its efficacy. MethodsA retrospective case-control study was conducted to analyze the clinical information of 280 patients with unilateral PTC at stages T1–T2 who underwent ipsilateral cervical lateral lymph node dissection and were diagnosed postoperatively via pathological examination in the Department of Thyroid Surgery (General Surgery) at the First Hospital of Shanxi Medical University from February 2019 to February 2024. The patients were randomly allocated into a training set and a test set in a 7∶3 ratio. The general, clinical, laboratory, and imaging data were collected for all patients. The univariate and multivariate logistic regression analyses were used to compare the differences in data of the patients between with and without LLNM in the training set. Then the risk factors affecting on the LLNM were used to construct a nomogram prediction model. The receiver operating characteristic (ROC) curve was generated for both the training and test sets, and the area under the ROC curve (AUC) was calculated to evaluate model discrimination. The calibration curve was used to assess model calibration, and decision curve analysis (DCA) was conducted to evaluate the clinical utility of the nomogram prediction model. ResultsA total of 280 patients were included, including 196 in the training set and 84 in the testing set. There were no statistically significant differences in the clinical and pathological data between the training set and the testing set (P>0.05). There were 147 cases of LLNM in the training set and 63 cases of LLNM in the testing set. The results of multivariate logistic regression analysis showed that the patients with T1–T2 stage unilateral PTC who were male in gender, had cancer lesions located in the upper pole, had central lymph node metastasis, had larger cancer lesions, and higher serum thyroid stimulating hormone level had a higher probability of developing ipsilateral cervical LLNM (P<0.05). The AUC (95%CI) of the nomogram prediction model constructed based on these risk factors in the training and testing sets were 0.822 (0.747, 0.897) and 0.838 (0.743, 0.933), respectively. The calibration curves of the training and testing sets roughly overlapped with the reference curve. The DCA results indicated that the net benefit for patients was positive when the threshold probabilities were within the ranges of 15% to 92% for the training set and 10% to 100% for the test set. ConclusionsThe results of this study suggest that gender, maximum cancer lesion diameter, cancer lesion location, central lymph node metastasis, and serum thyroid stimulating hormone are risk factors affecting the occurrence of ipsilateral cervical LLNM in T1–T2 stages unilateral PTC. The nomogram prediction model developed based on these risk factors demonstrates good discrimination, accuracy, and clinical applicability for its prediction.
ObjectiveTo evaluate the diagnostic efficacy of thyroglobulin in fine-needle aspirate fluid (FNA-Tg) for detecting cervical lateral lymph node metastases (LLNM) in differentiated thyroid cancer (DTC). MethodsThe clinical data of DTC patients who underwent (selective) cervical lateral lymph node dissection at the 900th Hospital of the Joint Logistics Support Force from February 1, 2021 to November 30, 2023 were retrospectively analyzed. The significance level (α) was set as 0.05. ResultsAccording to the inclusion and exclusion criteria, a total of 155 patients with 179 lymph nodes were included, among which 49 lymph nodes were not metastatic and 130 were metastatic. The results of the integral patients showed that the area under the receiver operating characteristic curve (AUC) of FNA-Tg for distinguishing cervical LLNM in the patients with DTC was superior to that of fine-needle aspiration cytology (FNAC). The AUCs (95% confidence intervals) were 0.973 (0.950, 0.995) and 0.778 (0.708, 0.849) respectively, P<0.05, and the AUC (95% confidence interval) of the combination of the two was higher [0.978 (0.959, 0.997)]. The optimal diagnostic threshold of FNA-Tg was determined to be 16.45 μg/L or FNA-Tg/serum thyroglobulin (sTg) was 1.02. After stratification based on the size of the lymph nodes, a paired analysis of the two methods (FNA-Tg and FNAC) showed that the diagnostic efficiency of FNA-Tg was significantly higher than that of FNAC only when the short diameter of the lymph node was ≤0.8 cm [0.955 (0.919, 0.992) vs. 0.718 (0.630, 0.806), P<0.001], and there was no additional benefit from the combination of the two [0.950 (0.912, 0.989)]. ConclusionsThe results of this study suggest that FNA-Tg shows a good diagnostic efficacy for cervical LLNM in patients with DTC, especially has an obvious advantage for small lymph nodes with a short-axis diameter of lymph node ≤0.8 cm. Its optimal diagnostic threshold is 16.45 μg/L or FNA-Tg/sTG is 1.02.