Papillary thyroid carcinoma nodal surgery directed by a preoperative radiographic map utilizing CT scan and ultrasound in all primary and reoperative patients

Diagnostic yield of thyroid CT in differentiated thyroid carcinoma according to treatment response

OBJECTIVES

To evaluate the diagnostic yield of thyroid CT in patients with post-treatment differentiated thyroid carcinoma (DTC) stratified by treatment response.

MATERIALS AND METHODS

This retrospective study included DTC patients who underwent total thyroidectomy and radioactive iodine ablation, followed by thyroid CT. Patients were categorized into response assessment groups according to the American Thyroid Association guidelines: excellent response (ER), biochemical incomplete response (BIR), indeterminate response (IR), and structural incomplete response (SIR). Diagnostic yield was defined as the proportion of patients with recurrent tumors among all patients. The yields of ER, BIR, and IR were compared. For IR, subgroup analyses were performed based on the presence of indeterminate lesions on ultrasound (US). Chi-squared tests with Bonferroni correction were used to compare the diagnostic yields between groups.

RESULTS

A total of 450 patients (mean age, 44.9 ± 13.4 years; 164 men) were included. The overall diagnostic yield of thyroid CT was 15.3% (69/450; 95% confidence interval [CI]: 12.3-19%). Yields for the ER, BIR, and IR groups were 2% (4/201; 95% CI: 0.6-5.2%), 23.1% (12/52; 95% CI: 13.6-36.3%), and 26.9% (53/197; 95% CI: 21.2-33.5%), respectively. Among IR patients, the yield was significantly lower in US-negative patients (7.5%, 7/93; 95% CI: 3.5-15%) compared to those with indeterminate US lesions (44.2%, 46/104; 95% CI: 35.1-53.8%) (p < 0.001).

CONCLUSION

The diagnostic yield of thyroid CT varies according to the treatment response; it was low in ER and US-negative IR but higher in BIR and IR with indeterminate US lesions.

KEY POINTS

Question Guidelines recommend considering CT for follow-up in DTC based on treatment response, but the diagnostic yield of CT remains underexplored. Findings The diagnostic yield of CT was low in an ER and US-negative IR but higher in BIR and US-positive IR. Clinical relevance The diagnostic yield of thyroid CT varies according to treatment response. Utilizing CT based on treatment response may enhance the detection of recurrent tumors or clarify unclear findings on US.

Impact of nodal status evaluation on therapeutic strategy for clinically unifocal T1b/small T2 node negative papillary thyroid carcinoma

PURPOSE

In absence of nodal metastases or aggressive features, thyroid lobectomy (TL) should be preferred over total thyroidectomy (TT) for 1-4 cm unifocal, papillary thyroid carcinoma (PTC). However, occult, despite non-microscopic (≥2 mm), nodal metastases may be present in clinically node-negative (cN0) PTC.

METHODS

Among 4216 thyroidectomies for malignancy (2014-2023), 110 TL plus ipsilateral central neck dissection (I-CND) were scheduled for unifocal cT1b/small cT2 (≤3 cm) cN0 PTCs. Frozen section examination (FSE) of removed nodes was performed: when positive, completion thyroidectomy (CT) was accomplished during the same procedure. In presence of aggressive pathologic features, CT was suggested within 6 months from index operation.

RESULTS

FSE was positive for occult not-microscopic nodal metastases in 33 cases (30%), underwent synchronous CT. Among the remaining 77 patients, 24 (31.2%) were scheduled for CT, after multidisciplinary tumor board discussion, due to at least 2 high-risk factors. The median number of removed and metastatic nodes was 8 (5-11) and 2 (1-5), respectively, at definitive histopathology. Furthermore, multifocality was present in 53 (48.2%) cases, lymphovascular invasion in 66 (60%) cases, aggressive subtypes in 20 (18.2%) cases and extracapsular invasion in 5 (4.5%) cases. Overall, 57 (51.8%) patients underwent immediate or delayed CT.

CONCLUSION

More than 50% of patients with unifocal cT1b/small cT2 cN0 PTC scheduled for TL may be eligible for CT because of aggressive tumor features. An intraoperative decision-making approach based on I-CND and nodes FSE may ensure accurate staging and risk stratification, thus reducing the risk of recurrence and the need for reoperation.

Enhancement on CT for preoperative diagnosis of metastatic lymph nodes in thyroid cancer: a comparison across experience levels

OBJECTIVES

To investigate the diagnostic performance and interobserver agreement of quantitative CT parameters indicating strong lymph node (LN) enhancement in differentiated thyroid cancer (DTC), comparing them with qualitative analysis by radiologists of varying experience.

MATERIALS AND METHODS

This study included 463 LNs from 399 patients with DTC. Three radiologists independently analyzed strong LN enhancement on CT. Qualitative analysis of strong enhancement was defined as LN cortex showing greater enhancement than adjacent muscles on the arterial phase. Quantitative analysis included the mean attenuation value (MAV) of LN on arterial phase (LNA) and venous phase (LNV), LNA normalized to the common carotid artery (NAVCCA), internal jugular vein (NAVIJV), and sternocleidomastoid muscle (NAVSCM), attenuation difference [AD; (LNA - MAVSCM)], and relative washout ratio [((LNA - LNV)/LNA) × 100]. The interobserver agreement and diagnostic performance of the quantitative and qualitative analyses were evaluated.

RESULTS

Interobserver agreement was excellent for all quantitative CT parameters (ICC, 0.83-0.94) and substantial for qualitative assessment (κ = 0.61). All CT parameters except for LNV showed good diagnostic performance for metastatic LNs (AUC, 0.81-0.85). NAVCCA (0.85, 95% CI: 0.8-0.9) and AD (0.85, 95% CI: 0.81-0.89) had the highest AUCs. All quantitative parameters except for NAVIJV had significantly higher AUCs than qualitative assessments by inexperienced radiologists, with no significant difference from assessments by an experienced radiologist.

CONCLUSION

Quantitative assessment of LN enhancement on arterial phase CT showed higher interobserver agreement and AUC values than qualitative analysis by inexperienced radiologists, supporting the need for a standardized quantitative CT parameter-based model for determining strong LN enhancement.

CLINICAL RELEVANCE STATEMENT

When assessing strong LN enhancement in DTC, quantitative CT parameters indicating strong enhancement can improve interobserver agreement, regardless of experience level. Therefore, the development of a standardized diagnostic model based on quantitative CT parameters might be necessary.

KEY POINTS

Accurate preoperative assessment of LN metastasis in thyroid cancer is crucial. Quantitative CT parameters indicating strong LN enhancement demonstrated excellent interobserver agreement and good diagnostic performance. Quantitative assessment of contrast enhancement offers a more objective model for the identification of metastatic LNs.

A machine learning model utilizing Delphian lymph node characteristics to predict contralateral central lymph node metastasis in papillary thyroid carcinoma: a prospective multicenter study

BACKGROUND

This study aimed to use artificial intelligence (AI) to integrate various radiological and clinical pathological data to identify effective predictors of contralateral central lymph node metastasis (CCLNM) in patients with papillary thyroid carcinoma (PTC) and to establish a clinically applicable model to guide the extent of surgery.

METHODS

This prospective cohort study included 603 patients with PTC from three centers. Clinical, pathological, and ultrasonographic data were collected and utilized to develop a machine learning (ML) model for predicting CCLNM. Model development at the internal center utilized logistic regression along with other ML algorithms. Diagnostic efficacy was compared among these methods, leading to the adoption of the final model (random forest). This model was subject to AI interpretation and externally validated at other centers.

RESULTS

CCLNM was associated with multiple pathological factors. The Delphian lymph node metastasis ratio, ipsilateral central lymph node metastasis number, and presence of ipsilateral central lymph node metastasis were independent risk factors for CCLNM. Following feature selection, a Delphian lymph node-CCLNM (D-CCLNM) model was established using the Random forest algorithm based on five attributes. The D-CCLNM model demonstrated the highest area under the curve (AUC; 0.9273) in the training cohort and exhibited high predictive accuracy, with AUCs of 0.8907 and 0.9247 in the external and validation cohorts, respectively.

CONCLUSIONS

The authors developed a new, effective method that uses ML to predict CCLNM in patients with PTC. This approach integrates data from Delphian lymph nodes and clinical characteristics, offering a foundation for guiding surgical decisions, and is conveniently applicable in clinical settings.

Preoperative ultrasonography parathyroid gland mapping can improve identification of normal parathyroid gland during thyroidectomy: A propensity score-matched case-control study

BACKGROUND

Accurate intraoperative identification of normal parathyroid glands (PTGs) is vital to avoid hypocalcemia post total thyroidectomy. Although ultrasonography (US) has been shown to identify normal PTGs, the significance of preoperative US PTG mapping in this context is not well studied. This study evaluated the impact of preoperative US PTG mapping on intraoperative identification of normal PTGs during total thyroidectomy.

METHODS

The study involved 161 consecutive patients who underwent total thyroidectomy between January 2020 and June 2022. These included patients without preoperative US PTG mapping (group 1, n = 91) and those with the mapping (group 2, n = 70). Propensity score matching yielded 61 matched patients from each group. We developed a preoperative US PTG mapping technique combining US identification of normal PTGs with their localization on thyroid CT images. The intraoperative detectability of normal PTGs during thyroid surgery and detectability of normal PTGs by the preoperative US mapping were assessed by the number of PTGs identified per patient and by location.

RESULTS

In the matched cohort, group 2 demonstrated a higher median number of identified PTGs (3 vs. 2, p = 0.011), a greater proportion of patients with three or more identified PTGs (65.5% vs. 44.3%, p = 0.018), and a higher ratio of identified to expected PTGs (70.5% vs. 60.2%, p = 0.011) than group 1. In group 2, the median number of normal PTGs identified preoperatively was 3, with at least one identified in 95.7% of patients, two or more in 84.3%, three or more in 52.9%, and four or five in 24.3%.

CONCLUSIONS

Preoperative US PTG mapping identified two or more normal PTGs in the majority of adult patients undergoing total thyroidectomy. Those with preoperative mapping showed a higher number of intraoperatively identified normal PTGs, including inferior PTGs, compared to those without. This technique appears to enhance the intraoperative identification of normal PTGs, thereby potentially improving surgical outcomes in total thyroidectomy.

First Hit the Best Hit for Advanced Differentiated Papillary Thyroid Carcinoma?

Optimal upfront surgery with precise and objective image mapping is perhaps the way to go to enhance treatment outcomes and mitigate the use of post-operative radioiodine therapy. With the advent of targeted agents and precision medicine, it is now possible to undertake surgery for very advanced or inoperable differentiated thyroid cancers, followed by appropriate adjuvant treatment.

Risk stratification for central lymph node metastasis in mono-focal papillary thyroid carcinoma patients with encapsulated tumor as confirmed by preoperative ultrasound: a multi-center analysis

PURPOSES

Mono-focal papillary thyroid carcinoma (PTC) patients with encapsulated tumor have traditionally been considered as low central lymph node metastasis (CLNM) risk subgroup. The aim of the research was to quantitatively predict the probability of CLNM for mono-focal PTC patients with encapsulated tumor as confirmed by preoperative ultrasound based on pre- and post-operative indexes respectively to guide the selection of prophylactic central lymph node dissection (CLND) and follow-up strategies.

METHODS

A total of 1014 mono-focal PTC patients with encapsulated tumor as confirmed by preoperative ultrasound from three medical centers were retrospectively analyzed, with 534 patients served as Training group and 480 patients as Validation group.

RESULTS

Multivariate analyses showed that age < 55 years old, male, clinical maximum tumor diameter (cMTD) > 0.5 cm, pathological maximum tumor diameter (pMTD) > 0.5 cm, and the presence of microscopic thyroid capsular invasion (mTCI) were independent CLNM risk factors. These were used to construct two nomograms that can effectively predict the central neck involvement in mono-focal PTC patients with encapsulated tumor. The first nomogram (pre-model) provides quantitative assessment on the necessity of prophylactic CLND, while the second nomogram (post-model) informs postoperative follow-up strategies.

CONCLUSIONS

Meticulous and comprehensive stratification flow charts that quantitatively evaluate the risk of central lymph node metastasis both pre- and post-operatively were constructed for mono-focal PTC patients with encapsulated tumor as confirmed by preoperative ultrasound, which may benefit both clinical decision-making of prophylactic CLND and postoperative follow-up strategies for the management of neck regions.

A CT based radiomics analysis to predict the CN0 status of thyroid papillary carcinoma: a two- center study

OBJECTIVES

To develop and validate radiomics model based on computed tomography (CT) for preoperative prediction of CN0 status in patients with papillary thyroid carcinoma (PTC).

METHODS

A total of 548 pathologically confirmed LNs (243 non-metastatic and 305 metastatic) two distinct hospitals were retrospectively assessed. A total of 396 radiomics features were extracted from arterial-phase CT images, where the strongest features containing the most predictive potential were further selected using the least absolute shrinkage and selection operator (LASSO) regression method. Delong test was used to compare the AUC values of training set, test sets and cN0 group.

RESULTS

The Rad-score showed good discriminating performance with Area Under the ROC Curve (AUC) of 0.917(95% CI, 0.884 to 0.950), 0.892 (95% CI, 0.833 to 0.950) and 0.921 (95% CI, 868 to 0.973) in the training, internal validation cohort and external validation cohort, respectively. The test group of CN0 with a AUC of 0.892 (95% CI, 0.805 to 0.979). The accuracy was 85.4% (sensitivity = 81.3%; specificity = 88.9%) in the training cohort, 82.9% (sensitivity = 79.0%; specificity = 88.7%) in the internal validation cohort, 85.4% (sensitivity = 89.7%; specificity = 83.8%) in the external validation cohort, 86.7% (sensitivity = 83.8%; specificity = 91.3%) in the CN0 test group.The calibration curve demonstrated a significant Rad-score (P-value in H-L test > 0.05). The decision curve analysis indicated that the rad-score was clinically useful.

CONCLUSIONS

Radiomics has shown great diagnostic potential to preoperatively predict the status of cN0 in PTC.

Deep learning predicts cervical lymph node metastasis in clinically node-negative papillary thyroid carcinoma

OBJECTIVES

Precise determination of cervical lymph node metastasis (CLNM) involvement in patients with early-stage thyroid cancer is fairly significant for identifying appropriate cervical treatment options. However, it is almost impossible to directly judge lymph node metastasis based on the imaging information of early-stage thyroid cancer patients with clinically negative lymph nodes.

METHODS

Preoperative US images (BMUS and CDFI) of 1031 clinically node negative PTC patients definitively diagnosed on pathology from two independent hospitals were divided into training set, validation set, internal test set, and external test set. An ensemble deep learning model based on ResNet-50 was built integrating clinical variables, BMUS, and CDFI images using a bagging classifier to predict metastasis of CLN. The final ensemble model performance was compared with expert interpretation.

RESULTS

The ensemble deep convolutional neural network (DCNN) achieved high performance in predicting CLNM in the test sets examined, with area under the curve values of 0.86 (95% CI 0.78-0.94) for the internal test set and 0.77 (95% CI 0.68-0.87) for the external test set. Compared to all radiologists averaged, the ensemble DCNN model also exhibited improved performance in making predictions. For the external validation set, accuracy was 0.72 versus 0.59 (p = 0.074), sensitivity was 0.75 versus 0.58 (p = 0.039), and specificity was 0.69 versus 0.60 (p = 0.078).

CONCLUSIONS

Deep learning can non-invasive predict CLNM for clinically node-negative PTC using conventional US imaging of thyroid cancer nodules and clinical variables in a multi-institutional dataset with superior accuracy, sensitivity, and specificity comparable to experts.

CRITICAL RELEVANCE STATEMENT

Deep learning efficiently predicts CLNM for clinically node-negative PTC based on US images and clinical variables in an advantageous manner.

KEY POINTS

• A deep learning-based ensemble algorithm for predicting CLNM in PTC was developed. • Ultrasound AI analysis combined with clinical data has advantages in predicting CLNM. • Compared to all experts averaged, the DCNN model achieved higher test performance.

Central Neck Lymph Node Size Measured by Ultrasound Significantly Predicts Central Neck Lymph Node Metastasis of Papillary Thyroid Carcinoma

Objective: The aim of this study was to investigate whether Central lymph node (CLN) size as measured by an ultrasound can significantly predict CLN metastasis of papillary thyroid carcinoma (PTC). Materials and methods: This retrospective chart review of patients diagnosed with PTC who underwent ultrasound and central neck dissection (CND). We excluded patients who received previous thyroid surgery or radiation. We analyzed the correlation between CLN size and characteristics by ultrasound and histopathologic findings among positive CLN patients. Results: Of the 48 patients who underwent preoperative ultrasound and CND, 34 patients had positive CLN identified by ultrasound. The positive predictive value, negative predictive value, sensitivity, specificity, and accuracy of ultrasound in this diagnostic setting was 88.0%, 21.0%, 73.2%, 42.9%, and 68.7%, respectively. The risk of CLN metastasis of PTC was 67.7% and 85.7% for lymph node size 3.1 to 4 mm and 4.1 to 5 mm, respectively. The risk increased to 100% when the lymph node size was >5 mm. Positive preoperative ultrasound of lateral neck lymph node was found to be a significant risk factor for CLN metastasis (P = .003). Conclusion: Ultrasound was found to be an effective preoperative evaluation in patients with PTC to determine the likelihood of CLN metastasis and whether CND is indicated, especially in the ultrasound-positive central lymph node. A high risk of metastasis was found in CLN size >3 mm by ultrasound, and the risk dramatically increased in CLN size >5 mm. We also found positive lateral neck node from preoperative ultrasound to be a significant risk factor for CLN metastasis.

Impact of Additional Preoperative Computed Tomography Imaging on Staging, Surgery, and Postsurgical Survival in Patients With Papillary Thyroid Carcinoma

OBJECTIVE

We investigated the impacts of computed tomography (CT) added to ultrasound (US) for preoperative evaluation of patients with papillary thyroid carcinoma (PTC) on staging, surgical extent, and postsurgical survival.

MATERIALS AND METHODS

Consecutive patients who underwent surgery for PTC between January 2015 and December 2015 were retrospectively identified. Of them, 584 had undergone preoperative additional thyroid CT imaging (CT + US group), and 859 had not (US group). Inverse probability of treatment weighting (IPTW) and propensity score matching (PSM) were used to adjust for 14 variables and balance the two groups. Changes in nodal staging and surgical extent caused by CT were recorded. The recurrence-free survival and distant metastasis-free survival after surgery were compared between the two groups.

RESULTS

In the CT + US group, discordant nodal staging results between CT and US were observed in 94 of 584 patients (16.1%). Of them, CT accurately diagnosed nodal staging in 54 patients (57.4%), while the US provided incorrect nodal staging. Ten patients (1.7%) had a change in the extent of surgery based on CT findings. Postsurgical recurrence developed in 3.6% (31 of 859) of the CT + US group and 2.9% (17 of 584) of the US group during the median follow-up of 59 months. After adjustment using IPTW (580 vs. 861 patients), the CT + US group showed significantly higher recurrence-free survival rates than the US group (hazard ratio [HR], 0.52 [95% confidence interval {CI}, 0.29-0.96]; P = 0.037). PSM analysis (535 patients in each group) showed similar HR without statistical significance (HR, 0.60 [95% CI, 0.31-1.17]; P = 0.134). For distant metastasis-free survival, HRs after IPTW and PSM were 0.75 (95% CI, 0.17-3.36; P = 0.71) and 0.87 (95% CI, 0.20-3.80; P = 0.851), respectively.

CONCLUSION

The addition of CT imaging for preoperative evaluation changed nodal staging and surgical extent and might improve recurrence-free survival in patients with PTC.

Surgical and Biochemical Outcomes in Nerve Monitored Reoperation Surgery for Recurrent Papillary Thyroid Carcinoma

OBJECTIVE

To study the surgical and biochemical outcomes in nerve-monitored reoperation or revision surgery for recurrent thyroid cancers.

STUDY DESIGN

A single-center retrospective study.

SETTING

Tertiary center.

METHODS

We identified patients with recurrent papillary thyroid carcinoma (PTC) who underwent reoperation/revision surgery. Study outcomes were surgical complications frequency, recurrence, distant metastasis, and biological complete response (BCR) by comparing preoperative and postoperative thyroglobulin (Tg) levels.

RESULTS

Out of 227 patients, 33.9% presented for ≥2 reoperation surgeries. Nineteen (8.4%) had permanent preoperative hypoparathyroidism while 22 patients (9.7%) had preoperative vocal cord paralysis (VCP). Following reoperation surgery, there were 12 cases (5.3%) of permanent hypocalcemia and no cases of unexpected postoperative VCP. BCR was achieved in 31 patients (35.2%) with complete Tg data. Mean preoperative Tg was 47.7 ng/mL and was 19.7 ng/mL postoperatively (p = .003). The cervical nodal recurrence rate after final surgery was 7.0% (n = 16).

CONCLUSION

Reoperation surgery for recurrent PTC may help achieve biochemical remission regardless of age or the number of prior surgeries.

Role of computed tomography in the evaluation of regional metastasis in well-differentiated thyroid cancer

Background

Accurate neck staging is essential for performing appropriate surgery and avoiding undue morbidity in thyroid cancer. The modality of choice for evaluation is ultrasonography (US), which has limitations, particularly in the central compartment, that can be overcome by adding a computed tomography (CT).

Methods

A total of 314 nodal levels were analyzed in 43 patients with CT, and US; evaluations were done between January 2013 and November 2015. The images were reviewed by two radiologists independently who were blinded to histopathological outcomes. The sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), and accuracy of US, CT, and US + CT were calculated using histology as the gold standard.

Results

The overall sensitivity, specificity, PPV, and NPV for US, CT, and US + CT were 53.9%, 88.8%, 74.1%, and 76.4%; 81.2%, 68.0%, 60.1%, and 85.9%; and 84.6%, 66.0%, 59.6%, and 87.8%, respectively. The overall accuracy of the US was 75.80%, the CT scan was 72.93%, and the US + CT scan was 72.93%. For the lateral compartment, the sensitivity, specificity, PPV, and NPV for the US, CT, and US + CT were 56.6%, 91.4%, 77.1%, and 80.5%; 80.7%, 70.6%, 58.3%, and 87.8%; and 84.3%, 68.7%, 57.9%, and 89.6%, respectively. The accuracy of the US was 79.67%, the CT scan was 73.98%, and the US + CT scan was 73.98% for the lateral compartment. For the central compartment, the sensitivity, specificity, PPV, and NPV for the US, CT, and US + CT were 47.1%, 76.5%, 66.7%, and 59.1%; 82.4%, 55.9%, 65.1%, and 76.0%; and 85.3%, 52.9%, 64.4%, and 78.3%, respectively. The accuracy of the US was 61.76%, the CT scan was 69.12%, and the US + CT scan was 69.12% for the central compartment.

Conclusions

This study demonstrated that CT has higher sensitivity in detecting nodal metastasis; however, its role is complementary to US due to low specificity.

Validation of CT-Based Risk Stratification System for Lymph Node Metastasis in Patients With Thyroid Cancer

OBJECTIVE

To evaluate the computed tomography (CT) features for diagnosing metastatic cervical lymph nodes (LNs) in patients with differentiated thyroid cancer (DTC) and validate the CT-based risk stratification system suggested by the Korean Thyroid Imaging Reporting and Data System (K-TIRADS) guidelines.

MATERIALS AND METHODS

A total of 463 LNs from 399 patients with DTC who underwent preoperative CT staging and ultrasound-guided fine-needle aspiration were included. The following CT features for each LN were evaluated: absence of hilum, cystic changes, calcification, strong enhancement, and heterogeneous enhancement. Multivariable logistic regression analysis was performed to identify independent CT features associated with metastatic LNs, and their diagnostic performances were evaluated. LNs were classified into probably benign, indeterminate, and suspicious categories according to the K-TIRADS and the modified LN classification proposed in our study. The diagnostic performance of both classification systems was compared using the exact McNemar and Kosinski tests.

RESULTS

The absence of hilum (odds ratio [OR], 4.859; 95% confidence interval [CI], 1.593-14.823; P = 0.005), strong enhancement (OR, 28.755; 95% CI, 12.719-65.007; P < 0.001), and cystic changes (OR, 46.157; 95% CI, 5.07-420.234; P = 0.001) were independently associated with metastatic LNs. All LNs showing calcification were diagnosed as metastases. Heterogeneous enhancement did not show a significant independent association with metastatic LNs. Strong enhancement, calcification, and cystic changes showed moderate to high specificity (70.1%-100%) and positive predictive value (PPV) (91.8%-100%). The absence of the hilum showed high sensitivity (97.8%) but low specificity (34.0%). The modified LN classification, which excluded heterogeneous enhancement from the K-TIRADS, demonstrated higher specificity (70.1% vs. 62.9%, P = 0.016) and PPV (92.5% vs. 90.9%, P = 0.011) than the K-TIRADS.

CONCLUSION

Excluding heterogeneous enhancement as a suspicious feature resulted in a higher specificity and PPV for diagnosing metastatic LNs than the K-TIRADS. Our research results may provide a basis for revising the LN classification in future guidelines.

Quantitative analysis of dual-phase enhanced CT in cervical lymph node metastasis of papillary thyroid carcinoma: a comparative study along with pathological manifestations

PURPOSE

This study aimed to investigate the diagnostic value of dual-phase enhanced computed tomography (CT) in the cervical lymph node metastasis (LNM) of papillary thyroid carcinoma (PTC) by analyzing the dual-phase enhanced Hounsfield units (HUs) of lymph node and sternocleidomastoid muscle, and the ratio and difference.

METHODS

The CT arterial-phase and venous-phase imaging data of 143 metastasis-positive lymph nodes (MPLNs) in 88 cases and 172 metastasis-negative lymph nodes (MNLNs) in 128 cases with PTC were retrospectively analyzed. All lymph nodes were confirmed by surgical pathology. The arterial-phase HU of lymph nodes (ANHU), venous-phase HU of lymph nodes (VNHU), arterial-phase HU of the sternocleidomastoid muscle (AMHU) and venous-phase HU of the sternocleidomastoid muscle (VMHU) were measured, and their difference and ratio (ANHU-AMHU, ANHU/AMHU, VNHU-VMHU, VNHU/VMHU) were calculated. The cutoff values and corresponding diagnostic efficacy for diagnosing LNM in PTC were sought by performing the receiver operating characteristic curves. The maximum pathological diameter (MPD) measured on pathological sections of lymph nodes was compared with the maximum transverse diameter (MTD) and maximum sagittal diameter (MSD) and their average values on CT images.

RESULTS

The ANHU, and VNHU of MPLNs and MNLNs were 111.89 ± 33.26 and 66.12 (56.81-76.86) (P < 0.001), and 99.07 ± 23.27 and 75.47 ± 13.95 (P < 0.001), respectively. The area under the curve, sensitivity, and specificity of the arterial-phase three parameters (ANHU, ANHU-AMHU, ANHU/AMHU) for diagnosing LNM were (0.877-0.880), (0.755-0.769), and (0.901-0.913), respectively, and the venous-phase three parameters (VNHU, VNHU-VMHU, VNHU/VMHU) were (0.801-0.817), (0.650-0.678), and (0.826-0.901), respectively. Compared with MPD, MTD (Z = -2.686, P = 0.007) and MSD (Z = -3.539, P < 0.001) were significantly different, while (MTD + MSD)/2 was not statistically different (Z = -0.038b, P = 0.969).

CONCLUSION

In the differential diagnosis of cervical LNM of PTC by dual-phase enhanced CT angiography, the arterial phase had higher diagnostic efficacy.

Preoperative Evaluation of Thyroid Cancer: A Review of Current Best Practices

OBJECTIVE

The incidence of thyroid cancer has significantly increased in recent decades. Although most thyroid cancers are small and carry an excellent prognosis, a subset of patients present with advanced thyroid cancer, which is associated with increased rates of morbidity and mortality. The management of thyroid cancer requires a thoughtful individualized approach to optimize oncologic outcomes and minimize morbidity associated with treatment. Because endocrinologists usually play a key role in the initial diagnosis and evaluation of thyroid cancers, a thorough understanding of the critical components of the preoperative evaluation facilitates the development of a timely and comprehensive management plan. The following review outlines considerations in the preoperative evaluation of patients with thyroid cancer.

METHODS

A clinical review based on current literature was generated by a multidisciplinary author panel.

RESULTS

A review of considerations in the preoperative evaluation of thyroid cancer is provided. The topic areas include initial clinical evaluation, imaging modalities, cytologic evaluation, and the evolving role of mutational testing. Special considerations in the management of advanced thyroid cancer are discussed.

CONCLUSION

Thorough and thoughtful preoperative evaluation is critical for formulating an appropriate treatment strategy in the management of thyroid cancer.

A combination of computed tomography scan and ultrasound provides optimal detection of cervical lymph node metastasis in papillary thyroid carcinomas: A systematic review and meta-analysis

BACKGROUND

Lymph node metastasis (LNM) in patients with papillary thyroid carcinoma (PTC) is common. This meta-analysis assesses the diagnostic accuracy of computed tomography (CT), ultrasound (US), and CT + US in detecting central and lateral LNM.

METHODS

A systematic review and meta-analysis was performed by searching PubMed, Embase, and Cochrane for studies published up to April 2022. The pooled sensitivity, specificity, and diagnostic odds ratio (DOR) were calculated. The area under the curve (AUC) for summary receiver operating curves (sROC) were compared.

RESULTS

The study population included 7902 patients with a total of 15 014 lymph nodes. Twenty-four studies analyzed the sensitivity of the overall neck region in which dual CT + US imaging (55.9%) had greater sensitivities (p < 0.001) than either US (48.4%) or CT (50.4%) alone. The specificity of US alone (89.0%) was greater (p < 0.001) than CT alone (88.5%) or dual imaging (86.8%). The DOR for dual CT + US imaging was greatest (p < 0.001) at 11.134, while the AUCs of the three imaging modalities were similar (p > 0.05). Twenty-one studies analyzed the sensitivity of the central neck region in which both CT (45.8%) and CT + US imaging (43.4%) had greater sensitivities (p < 0.001) than US alone (35.3%). The specificity of all three modalities was higher than 85%. The DOR for CT (7.985) was greater than US alone (4.723, p < 0.001) or dual CT + US imaging (4.907, p = 0.015). The AUC of both CT + US (0.785) and CT alone (0.785) were significantly greater (p < 0.001) than US alone (0.685). Of the 19 studies that reported lateral LNM, CT + US imaging sensitivity (84.5%) was higher than CT alone (69.2%, p < 0.001) and US alone (79.7%, p = 0.038). The specificity of all imaging techniques was all greater than 80.0%. CT + US imaging DOR (35.573) was greater than CT (20.959, p = 0.024) and US (15.181, p < 0.001) individually. The AUC of independent imaging was high (CT: 0.863, US: 0.858) and improved significantly when combined (CT + US: 0.919, p = 0.024 and p < 0.001, respectively).

CONCLUSIONS

We report an up-to-date analysis elucidating the diagnostic accuracy of LNM detection by either CT, US, or in combination. Our work suggests dual CT + US to be the best for overall detection of LNM and CT to be preferable in detecting central LNM. The use of either CT or US alone may detect lateral LNM with acceptable accuracy, yet dual imaging (CT + US) significantly improved detection rates.

Hemithyroidectomy in Papillary Thyroid Cancers: A Prospective, Single Institutional Surgical Audit and Contemplating on the Clinical Implications of 2015 American Thyroid Association Guidelines

Papillary thyroid carcinoma (PTC) contributes to 88% of thyroid malignancies and its extent of surgical management has been a topic of debate in the past 2 decades. American thyroid association (ATA) recommendations have been periodically updated for its robust and evidence-based management. We present our experience in implementing 2015 ATA guidelines, assessment of surgical outcomes of hemithyroidectomy in PTC ≤ 4 cm and contemplating on the potential clinical implications of 2015 ATA guidelines. A prospective study in a cohort of Bethesda class V and VI PTC with nodule ≤ 4 cm who underwent Hemithyroidectomy between 2012 and 2020. Data on thyroid nodule evaluation, management, histopathology and follow up were used for risk stratification. Of 37 patients, 27 (72.9%) were low risk and 10 (37%) were intermediate risk ATA group. 4 (40%) intermediate risk patients had structural incomplete response and underwent completion thyroidectomy. 1 (2.7%) out of 4 completion surgery patients required adjuvant radio-ablation iodine (RAI) and 3 patients were under surveillance. Overall, 2 (5.4%) of 37 patients, 1 each from low and intermediate groups were given remnant RAI in view of aggressive histology, old age and unwillingness for a completion surgery. During follow up of 4.94 ± 2.4 years, 35 (94.5%) showed excellent response and 2 (5.4%) showed biochemical incomplete response. The difference in RFS between two groups was statistically significant with p < 0.001. Thyroid preserving surgery combined with real time risk stratification seems appropriate for low and intermediate risk PTC ≤ 4 cm.

Guidelines from the Brazilian society of surgical oncology regarding indications and technical aspects of neck dissection in papillary, follicular, and medullary thyroid cancers

Objective

The purpose of these guidelines is to provide specific recommendations for the surgical treatment of neck metastases in patients with papillary, follicular, and medullary thyroid carcinomas.

Materials and methods

Recommendations were developed based on research of scientific articles (preferentially meta-analyses) and guidelines issued by international medical specialty societies. The American College of Physicians' Guideline Grading System was used to determine the levels of evidence and grades of recommendations. The following questions were answered: A) Is elective neck dissection indicated in the treatment of papillary, follicular, and medullary thyroid carcinoma? B) When should central, lateral, and modified radical neck dissection be performed? C) Could molecular tests guide the extent of the neck dissection?

Results and conclusion

Recommendation 1: Elective central neck dissection is not indicated in patients with cN0 well-differentiated thyroid carcinoma or in those with noninvasive T1 and T2 tumors but may be considered in T3-T4 tumors or in the presence of metastases in the lateral neck compartments. Recommendation 2: Elective central neck dissection is recommended in medullary thyroid carcinoma. Recommendation 3: Selective neck dissection of levels II-V should be indicated to treat neck metastases in papillary thyroid cancer, an approach that decreases the risk of recurrence and mortality. Recommendation 4: Compartmental neck dissection is indicated in the treatment of lymph node recurrence after elective or therapeutic neck dissection; "berry node picking" is not recommended. Recommendation 5: There are currently no recommendations regarding the use of molecular tests in guiding the extent of neck dissection in thyroid cancer.

Nomograms for Prediction of High-Volume Lymph Node Metastasis in Papillary Thyroid Carcinoma Patients

OBJECTIVE

The coexistence rate between chronic lymphocytic thyroiditis (CLT) and papillary thyroid carcinoma (PTC) is quite high. Whether CLT influences metastatic lymph nodes remains uncertain. High-volume lymph node metastasis is recommended as an unfavorable pathological feature. We aimed to investigate risk factors for high-volume central lymph node metastasis (CLNM) and lateral lymph node metastasis (LLNM) in PTC patients.

STUDY DESIGN

Retrospective cohort study.

SETTING

Changzhou First People's Hospital.

METHODS

Clinicopathological characteristics of 1094 PTC patients who underwent surgery in our center from January 2019 to November 2021 were analyzed.

RESULTS

The number of metastatic lymph nodes in the central compartment and lateral compartment were lower in the CLT group. We demonstrated that age, BRAF V600E, shape, and the number of foci were risk factors for high-volume CLNM in patients with CLT. For patients without CLT, sex, age, tumor size, number of foci, and margin were risk factors for high-volume CLNM. Tumor size, number of foci, location, and CLNM were all risk factors for high-volume LLNM in patients with or without CLT. Body mass index was only associated with high-volume LLNM in CLT patients. All the above factors were incorporated into nomograms, which showed perfect discriminative ability.

CONCLUSION

Separate predictive systems should be used for CLT and non-CLT patients for a more accurate clinical assessment of lymph node status. Our nomograms of predicting high-volume CLNM and LLNM could facilitate risk-stratified management of PTC recurrence and treatment decisions.

Neck Surgery for Non-Well Differentiated Thyroid Malignancies: Variations in Strategy According to Histopathology

Lymph node metastases in non-well differentiated thyroid cancer (non-WDTC) are common, both in the central compartment (levels VI and VII) and in the lateral neck (Levels II to V). Nodal metastases negatively affect prognosis and should be treated to maximize locoregional control while minimizing morbidity. In non-WDTC, the rate of nodal involvement is variable and depends on the histology of the tumor. For medullary thyroid carcinomas, poorly differentiated thyroid carcinomas, and anaplastic thyroid carcinomas, the high frequency of lymph node metastases makes central compartment dissection generally necessary. In mucoepidermoid carcinomas, malignant peripheral nerve sheath tumors, sarcomas, and malignant thyroid teratomas or thyroblastomas, central compartment dissection is less often necessary, as clinical lymphnode involvement is less common. We aim to summarize the medical literature and the opinions of several experts from different parts of the world on the current philosophy for managing the neck in less common types of thyroid cancer.

Central and lateral neck involvement in papillary thyroid carcinoma patients with or without thyroid capsular invasion: A multi-center analysis

PURPOSES

To quantitatively predict the probability of cervical lymph node metastasis for papillary thyroid carcinomas (PTC) patients with or without thyroid capsular invasion (TCI), to guide the decision-making of management strategies for neck regions.

METHODS

A total of 998 PTC patients from three medical centers were retrospectively analyzed.

RESULTS

Patients with positive TCI (TCI group) exhibited higher risks for both CLNM and LLNM than those with negative TCI (no-TCI group). Patients receiving lateral lymph node dissection showed significantly higher incidence of relatively severe postoperative complications. For no-TCI group, factors including age less than 55 years old, male, the presence of bilateral disease and multifocality, and maximum tumor diameter (MTD)>=0.5cm were confirmed to be independent risk factors for CLNM, while the presence of bilateral disease and ipsilateral nodular goiter (iNG), and maximum positive CLN diameter (MCLND)>1.0cm independent factors for LLNM. Independent risk factors of LLNM for patients within the TCI group included MCLND>1.0cm, positive CLN number>=3, and the presence of iNG. Predictive models of CLNM and LLNM were established based on the aforementioned risk factors for patients within no-TCI and TCI groups. A meticulous and comprehensive risk stratification flow chart was established for a more accurate evaluation of central neck involvement including both CLNM and LLNM risk in PTC patients.

CONCLUSIONS

A meticulous and comprehensive stratification flow chart for PTC patients for quantitatively evaluating both CLNM and LLNM was constructed.

Diagnostic value of multiple diagnostic methods for lymph node metastases of papillary thyroid carcinoma: A systematic review and meta-analysis

OBJECTIVE

This study compared the diagnostic value of various diagnostic methods for lymph node metastasis (LNM) of papillary thyroid carcinoma (PTC) through network meta-analysis.

METHODS

In this experiment, databases such as CNKI, Wanfang, PubMed, and Web of Science were retrieved according to the Cochrane database, Prisma, and NMAP command manual. A meta-analysis was performed using STATA 15.0, and the value of the surface under the cumulative ranking curve (SUCRA) was used to determine the most effective diagnostic method. Quality assessments were performed using the Cochrane Collaboration's risk of bias tool, and publication bias was assessed using Deeks' funnel plot.

RESULTS

A total of 38 articles with a total of 6285 patients were included. A total of 12 diagnostic methods were used to study patients with LNM of PTC. The results showed that 12 studies were direct comparisons and 8 studies were indirect comparisons. According to the comprehensive analysis of the area of SUCRA, US+CT(86.8) had the highest sensitivity, FNAC had the highest specificity (92.4) and true positive predictive value (89.4), and FNAC+FNA-Tg had higher negative predictive value (99.4) and accuracy (86.8). In the non-invasive method, US+CT had the highest sensitivity, and the sensitivity (SEN) was [OR=0.59, 95% confidence interval (CI): (0.30, 0.89]. Among the invasive methods, the combined application of FNAC+FNA-Tg had higher diagnostic performance. The sensitivity was [OR=0.62, 95% CI: (0.26, 0.98)], the specificity (SPE) was [OR=1.12, 95% CI: (0.59, 1.64)], the positive predictive value was [OR=0.98, 95% CI: (0.59, 1.37)], the negative predictive value was [OR=0.64, 95% CI (0.38, 0.90)], and the accuracy was [OR=0.71, 95% CI: (0.31, 1.12)].

CONCLUSION

In the non-invasive method, the combined application of US+CT had good diagnostic performance, and in the invasive method, the combined application of FNAC+FNA-Tg had high diagnostic performance, and the above two methods were recommended.

Radiologist versus Non-Radiologist Detection of Lymph Node Metastasis in Papillary Thyroid Carcinoma by Ultrasound: A Meta-Analysis

Papillary thyroid carcinoma (PTC) is the most common thyroid cancer worldwide and is known to spread to adjacent neck lymphatics. Lymph node metastasis (LNM) is a known predictor of disease recurrence and is an indicator for aggressive resection. Our study aims to determine if ultrasound sonographers’ degree of training influences overall LNM detection. PubMed, Embase, and Scopus articles were searched and screened for relevant articles. Two investigators independently screened and extracted the data. Diagnostic test parameters were determined for all studies, studies reported by radiologists, and studies reported by non-radiologists. The total sample size amounted to 5768 patients and 10,030 lymph nodes. Radiologists performed ultrasounds in 18 studies, while non-radiologists performed ultrasounds in seven studies, corresponding to 4442 and 1326 patients, respectively. The overall sensitivity of LNM detection by US was 59% (95%CI = 58–60%), and the overall specificity was 85% (95%CI = 84–86%). The sensitivity and specificity of US performed by radiologists were 58% and 86%, respectively. The sensitivity and specificity of US performed by non-radiologists were 62% and 78%, respectively. Summary receiver operating curve (sROC) found radiologists and non-radiologists to detect LNM on US with similar accuracy (p = 0.517). Our work suggests that both radiologists and non-radiologists alike detect overall LNM with high accuracy on US.

A Combination of Contrast-Enhanced Ultrasound and Thyroglobulin Level in Fine-Needle Aspirates Improves Diagnostic Accuracy for Metastatic Lymph Nodes of Papillary Thyroid Carcinoma

OBJECTIVE

To evaluate the diagnostic performance of contrast-enhanced ultrasound (CEUS) combined with thyroglobulin (Tg) levels in fine-needle aspirates (FNA) washout fluid (FNA-Tg) in diagnosing cervical lymph node (LN) metastasis in papillary thyroid cancer (PTC) patients.

METHODS

Data from 190 LNs in 167 patients suspected of metastasis from the US between November 2018 and September 2020 were included. All subjects underwent FNA, CEUS, and FNA-Tg examinations. The final outcomes were confirmed by histopathological or cytological examination or follow-up imaging. Data were analyzed using the Wilcoxon rank-sum or chi-squared test. The diagnostic efficacy of FNA, CEUS, and FNA-Tg in diagnosing LNs was compared.

RESULTS

A cutoff value of 6.15 ng/ml (AUC 0.925, 95% confidence interval (CI) 0.885-0.966) successfully identified metastatic LNs. FNA missed 58 LN metastases, of these, 94.8% (55/58) were correctly diagnosed using the combination of CEUS and FNA-Tg. FNA-Tg showed higher sensitivity (90.2%), NPV (86.1%) and accuracy (88.9%) than either FNA (48.2, 57.4 and 69.5%, respectively) or CEUS (82.1, 67.7 and 70.5%, respectively) alone. The combination of CEUS, FNA and FNA-Tg resulted in maximal sensitivity (100%) and NPV (100%) but reduced specificity (51.3%) and overall diagnostic accuracy (80.0%). After adding FNA-Tg to discordant samples between CEUS and FNA, 81.9% of LNs (77/94) were correctly diagnosed.

CONCLUSIONS

The combination of FNA, FNA-Tg and CEUS was found to be a promising imaging tool in detecting metastatic LNs in PTC patients.

Diagnostic accuracy of ultrasound, CT and their combination in detecting cervical lymph node metastasis in patients with papillary thyroid cancer: a systematic review and meta-analysis

OBJECTIVES

To determine the diagnostic accuracy of ultrasound (US), CT and their combination in detecting cervical lymph node metastasis (CLNM) in patients with papillary thyroid cancer (PTC).

METHODS

Medline (via PubMed), Web of Science, Embase were searched to identify studies published till 5 December 2021 that used US and CT to detect CLNM in patients with PTC. The primary outcomes were sensitivity, specificity and diagnostic ORs in neck-level-based (lymph nodes are analysed by neck level) or patient-based (lymph nodes are analysed by patient) analysis. Secondary outcomes were sensitivity, specificity and DORs in the central and lateral compartments.

RESULTS

Fourteen studies (6167 patients with 11 601 neck lymph nodes) met the inclusion criteria. Based on the neck-level-based analysis, the pooled sensitivity, specificity and DORs were 0.35 (95% CI 0.34 to 0.37), 0.95 (95% CI 0.94 to 0.95) and 13.94 (95% CI 9.34 to 20.82) for US, were 0.46 (95% CI 0.44 to 0.47), 0.88 (95% CI 0.87 to 0.89) and 7.24 (95% CI 5.46 to 9.62) for CT, were 0.51 (95% CI 0.49 to 0.52), 0.85 (95% CI 0.84 to 0.86), 6.01 (95% CI 3.84 to 9.40) for the combination of US and CT. In the patient-based analysis, the pooled estimates of sensitivity, specificity and DOR were 0.41 (95% CI 0.36 to 0.46), 0.92 (95% CI 0.89 to 0.94) and 7.56 (95% CI 4.08 to 14.01) for US, were 0.49 (0.44 to 0.54), 0.91 (0.89 to 0.94), 9.40 (5.79 to 15.27) for CT, and were 0.64 (95% CI 0.57 to 0.71), 0.83 (95% CI 0.77 to 0.88), 8.59 (95% CI 5.37 to 13.76) for the combination of US and CT.

DISCUSSION

These findings suggest US, with a DOR almost twice that of CT in the neck-level-based analysis, was superior to CT in detecting CLNM in patients with PTC, especially in the lateral compartment. The combination of US and CT increased the sensitivity from 41%-49% for the individual modalities to 64% for combined modalities in the patient-based analysis.

Ultrasonography of the thyroid, parathyroids, and beyond

Background

Ultrasonography has become an essential tool for the evaluation and management of thyroid and parathyroid diseases. Its applications extend beyond neck endocrine conditions to a multitude of pathologies within the head and neck region.

Objectives

Our study aimed to: (1) provide a broad review of neck ultrasonography and key findings in neck endocrine diseases; (2) support skilled performance office-based diagnostic ultrasonography and its varied applications.

Materials and methods

A review of the current literature was supplemented with clinical examples of key ultrasonographic findings.

Results

Current applications and key findings of ultrasonography in the diagnosis and management of neck endocrine conditions are reviewed.

Conclusion

Ultrasonography is a fundamental component in the evaluation and management of neck endocrine diseases. The reader is encouraged to use this review to enhance office-based performance and application of ultrasonography.

Video online

The online version of this article contains 11 additional videos. They are provided to illustrate some of the dynamic aspects of US performance. The article and the videos are available online (10.1007/s00106-022-01162-0). The videos can be found in the article back matter as “Electronic Supplementary Material”.

Cervical lymph node metastases in papillary thyroid cancer: Preoperative staging with ultrasound and/or computed tomography

Preoperative screening of potential risk of lymph node metastasis is necessary for thyroidectomy plus lymph node dissection. The 2015 American thyroid association management guidelines do not recommend prophylactic cervical lymph node resection without clinical evidence of metastasis. Ultrasound is recommended imaging method and routine computed tomography is not recommended by the 2015 American thyroid association management guidelines for screening of lymph node metastasis. The objective of the study was to compare the diagnostic performance of ultrasound against that of computed tomography for screening cervical lymph node metastasis of patients with papillary thyroid cancer before thyroidectomy plus lymph node dissection.Data regarding preoperative neck ultrasound, neck computed tomography, and physical examination of the head and neck and postoperative pathological results of a total of 185 patients (age > 18 years) with a diagnosis of papillary thyroid cancer who had suspicious lymph nodes on preoperative imaging and treated by thyroidectomy plus lymph node dissection for the therapeutic purpose were collected and analyzed.Sensitivity (78.09% vs 75.28%, P < .0001) and accuracy (77.29% vs 75.13%, P = .0004) of neck computed tomography scanning to detect cervical lymph node metastasis were higher than those of neck ultrasound scanning. Sensitivity, accuracy, positive clinical utility, and negative clinical utility for neck ultrasound scanning plus neck computed tomography scanning to detect cervical lymph node metastasis were higher among all index tests (P < .05 for all) and were statistically the same as those of surgical pathology (P > .05 for all). The working areas for decision-making of thyroidectomy plus lymph node dissection of the physical examination, neck ultrasound, the neck computed tomography, and the neck ultrasound scanning plus the neck computed tomography scanning were 0 to 0.691 diagnostic confidence/lesion, 0 to 0.961 diagnostic confidence/lesion, 0 to 0.944 diagnostic confidence/lesion, and 0 to 0.981 diagnostic confidence/lesion, respectively.Besides the neck ultrasound, the neck computed tomography scanning can be used as a complementary imaging method to detect cervical lymph node metastasis of patients with papillary thyroid cancer before thyroidectomy plus lymph node dissection.Level of evidence: III.Technical efficacy stage: 2.

LASSO-based machine learning models for the prediction of central lymph node metastasis in clinically negative patients with papillary thyroid carcinoma

BACKGROUND

The presence of central lymph node metastasis (CLNM) is crucial for surgical decision-making in clinical N0 (cN0) papillary thyroid carcinoma (PTC) patients. We aimed to develop and validate machine learning (ML) algorithms-based models for predicting the risk of CLNM in cN0 patients.

METHODS

A total of 1099 PTC patients with cN0 central neck from July 2019 to March 2022 at our institution were retrospectively analyzed. All patients were randomly split into the training dataset (70%) and the validation dataset (30%). Eight ML algorithms, including the Logistic Regression, Gradient Boosting Machine, Extreme Gradient Boosting (XGB), Random Forest (RF), Decision Tree, Neural Network, Support Vector Machine and Bayesian Network were used to evaluate the risk of CLNM. The performance of ML models was evaluated by the area under curve (AUC), sensitivity, specificity, and decision curve analysis (DCA).

RESULTS

We firstly used the LASSO Logistic regression method to select the most relevant factors for predicting CLNM. The AUC of XGB was slightly higher than RF (0.907 and 0.902, respectively). According to DCA, RF model significantly outperformed XGB model at most threshold points and was therefore used to develop the predictive model. The diagnostic performance of RF algorithm was dependent on the following nine top-rank variables: size, margin, extrathyroidal extension, sex, echogenic foci, shape, number, lateral lymph node metastasis and chronic lymphocytic thyroiditis.

CONCLUSION

By incorporating clinicopathological and sonographic characteristics, we developed ML-based models, suggesting that this non-invasive method can be applied to facilitate individualized prediction of occult CLNM in cN0 central neck PTC patients.

Imaging features of sentinel lymph node mapped by multidetector-row computed tomography lymphography in predicting axillary lymph node metastasis

INTRODUCTION

Accurately assessing axillary lymph node (ALN) status in breast cancer is vital for clinical decision making and prognosis. The purpose of this study was to evaluate the predictive value of sentinel lymph node (SLN) mapped by multidetector-row computed tomography lymphography (MDCT-LG) for ALN metastasis in breast cancer patients.

METHODS

112 patients with breast cancer who underwent preoperative MDCT-LG examination were included in the study. Long-axis diameter, short-axis diameter, ratio of long-/short-axis and cortical thickness were measured. Logistic regression analysis was performed to evaluate independent predictors associated with ALN metastasis. The prediction of ALN metastasis was determined with related variables of SLN using receiver operating characteristic (ROC) curve analysis.

RESULTS

Among the 112 cases, 35 (30.8%) cases had ALN metastasis. The cortical thickness in metastatic ALN group was significantly thicker than that in non-metastatic ALN group (4.0 ± 1.2 mm vs. 2.4 ± 0.7 mm, P < 0.001). Multi-logistic regression analysis indicated that cortical thickness of > 3.3 mm (OR 24.53, 95% CI 6.58-91.48, P < 0.001) had higher risk for ALN metastasis. The best sensitivity, specificity, negative predictive value(NPV) and AUC of MDCT-LG for ALN metastasis prediction based on the single variable of cortical thickness were 76.2%, 88.5%, 90.2% and 0.872 (95% CI 0.773-0.939, P < 0.001), respectively.

CONCLUSION

ALN status can be predicted using the imaging features of SLN which was mapped on MDCT-LG in breast cancer patients. Besides, it may be helpful to select true negative lymph nodes in patients with early breast cancer, and SLN biopsy can be avoided in clinically and radiographically negative axilla.

Preoperative assessment of cervical lymph node metastases in patients with papillary thyroid carcinoma: Incremental diagnostic value of dual-energy CT combined with ultrasound

PURPOSE

To determine whether dual-energy CT (DECT) has incremental diagnostic value when combined with ultrasound (US) in the diagnosis of metastatic cervical lymph nodes (LNs) in patients with papillary thyroid carcinoma (PTC).

METHODS

This was a single-center retrospective cohort study of patients diagnosed with PTC between October 2019 and August 2020. US features of LNs to include hyperechogenicity, round shape, microcalcification, cystic component, and homogeneous/peripheral vascularity were considered suggestive of metastasis. The HU of arterial phase (HUarterial) and DECT-derived CT images [contrast media (CM) and areas under the 100 keV monoenergetic curve (AUC100keV)] were measured. Effective atomic numbers (Zeff), iodine concentration (mg/mL), and slope of the HU curve (λHU) were also obtained. The values for metastatic and benign LNs were compared using Student's t-test with false-discovery correction. Logistic regression with areas under the receiver operating characteristic curves (AUCs) were performed for predicting metastatic LNs.

RESULTS

A total of 102 patients were included (49 metastatic and 53 benign LNs; mean age, 46±15 years). Metastatic LNs showed significantly higher values for HUarterial, CM, Zeff, λHU, AUC100keV, and iodine concentration (all, P = 0.001). In logistic regression, the HUarterial demonstrated the highest AUC (0.824; 95% confidence interval [CI], 0.751-0.897), followed by CM HU (0.762; 95% CI, 0.679-0.846). Combination of DECT parameters with US features improved the AUC from 0.890 to 0.941.

CONCLUSION

Compared to US features alone, combination with DECT-derived quantitative parameters improved diagnostic performance in predicting metastatic cervical LNs in patients with PTC.

Diagnostic Test Accuracy of Ultrasonography vs Computed Tomography for Papillary Thyroid Cancer Cervical Lymph Node Metastasis: A Systematic Review and Meta-analysis

Importance

The use of ultrasonography (US) vs cross-sectional imaging for preoperative evaluation of papillary thyroid cancer is debated.

Objective

To compare thyroid US and computed tomography (CT) in the preoperative evaluation of papillary thyroid cancer for cervical lymph node metastasis (CLNM), as well as extrathyroidal disease extension.

Data Sources

MEDLINE and Embase were searched from January 1, 2000, to July 18, 2020.

Study Selection

Studies reporting on the diagnostic accuracy of US and/or CT in individuals with treatment-naive papillary thyroid cancer for CLNM and/or extrathyroidal disease extension were included. The reference standard was defined as histopathology/cytology or imaging follow-up. Independent title and abstract review (2515 studies) followed by full-text review (145 studies) was completed by multiple investigators.

Data Extraction and Synthesis

PRISMA guidelines were followed. Methodologic and diagnostic accuracy data were abstracted independently by multiple investigators. Risk of bias assessment was conducted using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool independently and in duplicate. Bivariate random-effects model meta-analysis and multivariable meta-regression modeling was used.

Main Outcomes and Measures

Diagnostic test accuracy of US and CT of the neck for lateral and central compartment CLNM, as well as for extrathyroidal disease extension, determined prior to study commencement.

Results

A total of 47 studies encompassing 31 942 observations for thyroid cancer (12 771 with CLNM; 1747 with extrathyroidal thyroid extension) were included; 21 and 26 studies were at low and high risk for bias, respectively. Based on comparative design studies, US and CT demonstrated no significant difference in sensitivity (73% [95% CI, 64%-80%] and 77% [95% CI, 67%-85%], respectively; P = .11) or specificity (89% [95% CI, 80%-94%] and 88% [95% CI, 79%-94%], respectively; P = .79) for lateral compartment CLNM. For central compartment metastasis, sensitivity was higher in CT (39% [95% CI, 27%-52%]) vs US (28% [95% CI, 21%-36%]; P = .004), while specificity was higher in US (95% [95% CI, 92%-98%]) vs CT (87% [95% CI, 77%-93%]; P < .001). Ultrasonography demonstrated a sensitivity of 91% (95% CI, 81%-96%) and specificity of 47% (95% CI, 35%-60%) for extrathyroidal extension.

Conclusions and Relevance

The findings of this systematic review and meta-analysis suggest that further study is warranted of the role of CT for papillary thyroid cancer staging, possibly as an adjunct to US.

2021 Korean Thyroid Imaging Reporting and Data System and Imaging-Based Management of Thyroid Nodules: Korean Society of Thyroid Radiology Consensus Statement and Recommendations

Incidental thyroid nodules are commonly detected on ultrasonography (US). This has contributed to the rapidly rising incidence of low-risk papillary thyroid carcinoma over the last 20 years. The appropriate diagnosis and management of these patients is based on the risk factors related to the patients as well as the thyroid nodules. The Korean Society of Thyroid Radiology (KSThR) published consensus recommendations for US-based management of thyroid nodules in 2011 and revised them in 2016. These guidelines have been used as the standard guidelines in Korea. However, recent advances in the diagnosis and management of thyroid nodules have necessitated the revision of the original recommendations. The task force of the KSThR has revised the Korean Thyroid Imaging Reporting and Data System and recommendations for US lexicon, biopsy criteria, US criteria of extrathyroidal extension, optimal thyroid computed tomography protocol, and US follow-up of thyroid nodules before and after biopsy. The biopsy criteria were revised to reduce unnecessary biopsies for benign nodules while maintaining an appropriate sensitivity for the detection of malignant tumors in small (1-2 cm) thyroid nodules. The goal of these recommendations is to provide the optimal scientific evidence and expert opinion consensus regarding US-based diagnosis and management of thyroid nodules.

Computed tomography complements ultrasound for the differential diagnosis of traumatic neuroma from recurrent tumor in patients with postoperative thyroid cancer

OBJECTIVES

Traumatic neuromas (TNs) mimic recurrent tumors in US after total thyroidectomy (TT) and lateral neck dissection (LND) for thyroid cancer. We aimed to evaluate whether CT could complement US in the differential diagnosis of TNs from recurrent thyroid cancer in the dissected neck.

MATERIAL AND METHODS

We retrospectively included a total of 97 consecutive US-detected lesions (28 TNs and 69 recurrent tumors) in patients with a previous history of TT and LND for thyroid cancer. The lesions were classified as benign, indeterminate, or suspicious according to the presence of benign or suspicious features on US and CT. Imaging features and categories on US and CT were compared between TNs and recurrent tumors. The diagnostic performances of US and CT for differentiating between TNs and recurrent tumors were calculated.

RESULTS

On US, most TNs and recurrent tumors showed internal hyperechogenicity without hilar echogenicity or hilar vascularity and were categorized as suspicious lesions (23/28, 82.1% vs. 53/69, 76.8%). On CT, all TNs lacked strong enhancement without hilar fat or hilar vessel enhancement and were categorized as indeterminate lesions (28/28, 100%). In contrast, most recurrent tumors showed strong enhancement and were categorized as suspicious lesions (63/69, 91.3%). The addition of CT to US corrected 23 false-positive diagnoses in 28 TNs and 10 false-negative diagnoses in 69 recurrent tumors.

CONCLUSIONS

CT complements US for the correct differentiation of TNs from recurrent tumors in postoperative thyroid cancer patients. The addition of CT to US may prevent unnecessary painful biopsy or surgery.

KEY POINTS

• In the dissected neck, traumatic neuromas could mimic US suspicious LNs owing to its internal hyperechogenicity. • CT effectively differentiated traumatic neuromas from recurrent thyroid cancers by demonstrating significantly different enhancement patterns. • CT could complement US and may prevent unnecessary painful biopsy or surgery for US-detected lesions after thyroidectomy and neck dissection.

Cost-effectiveness of computed tomography nodal scan in patients with papillary thyroid carcinoma

OBJECTIVES

This study evaluates the cost-effectiveness of ultrasound (US) only; computed tomography (CT) only; and combined US-CT in a base-case that underwent total thyroidectomy for a newly diagnosed papillary thyroid carcinoma (PTC) (scenario I) or surgery for recurrent disease (scenario II).

MATERIALS AND METHODS

Markov chain model was developed comparing the above modalities. Follow-up time was set as 10 years. Costs and probabilities values are obtained from literature and the National Cancer Database.

RESULTS

Nodal mapping of the central compartment in both primary and recurrent PTC scenarios demonstrated combined utilization of preoperative US and CT is preferred over the use of US or CT separately; the final incurred management cost was [scenario I: U.S.$10,548.25 - scenario II: U.S.$11.197.88] and effectiveness was [scenario I: 6.875 Quality-adjusted-life-year (QALY) - scenario II: 6.871 QALY]. Nodal mapping of the lateral compartments favored US alone as the cost-effective modality in both scenarios; the final incurred management cost was [scenario I: U.S.$10,716.60 - scenario II: U.S.$11,247.92] and effectiveness was [scenario I: 6.879 QALY - scenario II: 6.883 QALY]. Sensitivity analysis demonstrated that for combined utilization of US and CT scans to remain cost-effective, the cost of a CT scan should be less than U.S.$1,127.54.

CONCLUSIONS

Based on the model, combined utilization of US and CT is cost-effective in nodal mapping patients with PTC.

2020 Imaging Guidelines for Thyroid Nodules and Differentiated Thyroid Cancer: Korean Society of Thyroid Radiology

Imaging plays a key role in the diagnosis and characterization of thyroid diseases, and the information provided by imaging studies is essential for management planning. A referral guideline for imaging studies may help physicians make reasonable decisions and minimize the number of unnecessary examinations. The Korean Society of Thyroid Radiology (KSThR) developed imaging guidelines for thyroid nodules and differentiated thyroid cancer using an adaptation process through a collaboration between the National Evidence-based Healthcare Collaborating Agency and the working group of KSThR, which is composed of radiologists specializing in thyroid imaging. When evidence is either insufficient or equivocal, expert opinion may supplement the available evidence for recommending imaging. Therefore, we suggest rating the appropriateness of imaging for specific clinical situations in this guideline.

Dual-source dual-energy thin-section CT combined with small field of view technique for small lymph node in thyroid cancer: a retrospective diagnostic study

Background

To evaluate the diagnostic performance of quantitative spectral parameters derived from dual-source dual-energy CT at small field of view (FOV) for small lymph node metastasis in thyroid cancer.

Methods

This was a retrospective diagnostic study. From 2016 to 2019, 280 patients with thyroid disease underwent thin-section dual-source dual-energy thyroid CT and thyroid surgery. The data of patients with lymph nodes having a short diameter of 2-6 mm was analyzed. The quantitative dual-energy CT parameters of targeted lymph nodes were measured, and all parameters between metastatic and non-metastatic lymph nodes were compared. These parameters were then fitted to univariable and multivariable binary logistic regression models. The diagnostic role of spectral parameters was analyzed by receiver operating characteristic (ROC) curves and compared with the McNemar test. Small FOV CT images and a mathematical model were used to judge the status of lymph nodes respectively, and then compared with the golden criterion-pathological diagnosis. The cut-off value of the model was 0.4419, with a sensitivity of 90.2% and a specificity of 92.7%.

Results

Of the 216 lymph nodes investigated in this study, 52.3% and 23.6% had a short diameter of 2-3 and 4 mm, respectively. Multiple quantitative CT parameters were significantly different between benign and malignant lymph nodes, and binary regression analysis was performed. The mathematical model was: p=ey/(1+ ey), y=-23.119+0.033× precontrast electron cloud density +0.076× arterial phase normalized iodine concentration +2.156× arterial phase normalized effective atomic number -0.540× venous phase slope of the spectral Hounsfield unit curve +1.676× venous phase iodine concentration. This parameter model had an AUC of 92%, with good discrimination and consistency, and the diagnostic accuracy was 90.3%. The diagnostic accuracy of the CT image model was 43.1%, and for lymph nodes with a short-diameter of 2-3 mm, the diagnostic accuracy was 22.1%.

Conclusions

The parameter model showed higher diagnostic accuracy than the CT image model for diagnosing small lymph node metastasis in thyroid cancer, and quantitative dual-energy CT parameters were very useful for small lymph nodes that were difficult to be diagnosed only on conventional CT images.

Trial registration

This study is retrospectively registered, and we have registered a prospective study (Registration number: ChiCTR2000035195; http://www.chictr.org.cn).

Dual-energy computed tomography could reliably differentiate metastatic from non-metastatic lymph nodes of less than 0.5 cm in patients with papillary thyroid carcinoma

BACKGROUND

Dual-energy computed tomography (DECT) has been widely applied to detect lymph node (LN) and lymph node metastasis (LNM) in various cancers, including papillary thyroid carcinoma (PTC). This study aimed to quantitatively evaluate metastatic cervical lymph nodes (LNs) <0.5 cm in patients with PTC using DECT, which has not been done in previous studies.

METHODS

Preoperative DECT data of patients with pathologically confirmed PTC were retrospectively collected and analyzed between May 2016 and June 2018. A total of 359 LNs from 52 patients were included. Diameter, iodine concentration (IC), normalized iodine concentration (NIC), and the slope of the energy spectrum curve (λHU) of LNs in the arterial and the venous phases were compared between metastatic and non-metastatic LNs. The optimal parameters were obtained from the receiver operating characteristic (ROC) curves. The generalized estimation equation (GEE) model was used to evaluate independent diagnostic factors for LNM.

RESULTS

A total of 139 metastatic and 220 non-metastatic LNs were analyzed. There were statistical differences of quantitative parameters between the two groups (P value 0.000-0.007). The optimal parameter for diagnosing LNM was IC in the arterial phase, and its area under the curve (AUC), sensitivity, and specificity were 0.775, 71.9%, and 73.6%, respectively. When the three parameters of diameter, IC in the arterial phase, and NIC in the venous phase were combined, the prediction efficiency was better, and the AUC was 0.819. The GEE results showed that LNs located in level VIa [odds ratio (OR) 2.030, 95% confidence interval (CI): 1.134-3.634, P=0.017], VIb (OR 2.836, 95% CI: 1.597-5.038, P=0.000), diameter (OR 2.023, 95% CI: 1.158-3.532, P=0.013), IC in the arterial phase (OR 4.444, 95% CI: 2.808-7.035, P=0.000), and IC in the venous phase (OR 5.387, 95% CI: 3.449-8.413, P=0.000) were independent risk factors for LNM in patients with PTC.

CONCLUSIONS

DECT had good diagnostic performance in the differentiation of cervical metastatic LNs <0.5 cm in patients with PTC.

Diagnostic values of F-18 FDG PET or PET/CT, CT, and US for Preoperative Lymph Node Staging in Thyroid Cancer: A Network Meta-Analysis

OBJECTIVE

This study compared the diagnostic performance of three different imaging modalities for preoperative lymph node (LN) staging in thyroid cancer patients, using a network meta-analysis (NMA).

METHODS

PubMed and Embase were searched to identify studies evaluating the performance of F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET or PET/CT), computed tomography (CT), and ultrasonography (US) for preoperative LN staging in thyroid cancer patients. The NMA included both patient- and lesion-based analyses. The surface under the cumulative ranking curve (SUCRA) values was used to decide on the most effective diagnostic method.

RESULTS

A total of 3,571 patients from 19 direct comparison studies using three different imaging modalities for preoperative LN staging in thyroid cancer patients were included. US showed the highest SUCRA values for positive predictive values (PPV), negative predictive values (NPV), and accuracy in detection of all cervical LN metastasis. F-18 FDG PET or PET/CT and US showed the highest SUCRA values for PPV and sensitivity, respectively, for central LN, and the highest SUCRA value of specificity and sensitivity, respectively, for lateral LN.

CONCLUSION

The results from this NMA indicate that F-18 FDG PET or PET/CT, CT, and US have complementary diagnostic roles for preoperative staging in thyroid cancer patients.

ADVANCES IN KNOWLEDGE

Using NMA, we comprehensively compared the different diagnostic values and limitations of F-18 FDG PET or PET/CT, CT, and US for the preoperative LN staging in thyroid cancer patients.

Development and validation of a nomogram for preoperative prediction of level VII nodal spread in papillary thyroid cancer: Radiologic-pathologic correlation

PURPOSE

To develop and validate a diagnostic nomogram for preoperative prediction of the level VII nodal spread in papillary thyroid cancer (PTC) by incorporating CT features.

METHODS

A dataset of 7896 patients experiencing thyroidectomy for thyroid cancer was collected retrospectively from two hospitals, and 300 patients were finally included in this study. The CT features of metastatic LN were extracted with a one by one match of radiologic-pathologic correlation. Multivariable binary logistic regression analysis was used to develop predicting model, and then a nomogram was developed utilizing a primary cohort of 152 patients from hospital #1. The nomogram was validated in external cohort of 62 patients from hospital #2 and an independent cohort of 86 patients from hospital #1. The performance of the nomogram was evaluated with respect to its calibration, discrimination.

RESULTS

531 LNs from 300 patients were analyzed. 42.6% LNs were > 5 mm in short diameter. A total of 7 selected CT features were significantly associated with LN status (P < 0.05), including nodular enhancement, cystic change, calcification and so on. These features were contained in the prediction nomogram. The model showed good discrimination and good calibration, with a C-index of 0.938 (95% CI, 0.913 to 0.963) and 0. 795 (95% CI, 0. 726 to 0.864) for the primary cohort and the validation cohort, respectively. Decision curve analysis demonstrated that the nomogram was clinically applicable.

CONCLUSIONS

This nomogram incorporating pathologically relevant CT features has demonstrated a high diagnostic value for predicting level VII nodal spread in PTC. Our work may help thyroid surgeon to decide whether upper mediastinal lymphadenectomy should be performed, which is associated with thoracotomy or other surgery.

Redo thyroid surgery without drains

PURPOSE

Redo thyroid surgery is associated with higher risk of hematoma than the initial thyroid surgery. We report a single surgeon's experience of performing redo thyroid surgery without drains.

METHODS

This retrospective single-institutional study evaluates the safety and efficiency of redo thyroid surgery without drains by comparing three groups of patients: those who underwent primary bilateral thyroidectomy (Group 1), those who underwent completion thyroidectomy (Group 2); and those who underwent thyroidectomy for recurrent thyroid diseases (Group 3).

RESULTS

The demographic characteristics did not differ among the groups. Substernal extension and hyperthyroidism were more frequent in group 1, whereas the weight of the resected thyroid gland was lower in groups 2 and 3. Hematoma occurred in 5%, 4%, and 4% of patients in Groups 1, 2, and 3, respectively. Postoperative transient hypocalcemia occurred in 19%, 16%, and 21% of patients in Groups 1, 2, and 3 respectively. The postoperative incidence of transient recurrent laryngeal nerve (RLN) paralysis in Groups 1, 2, and 3, was 6%, 7%, and 8%, respectively. The incidence of permanent unilateral RLN paralysis in Groups 2 and 3 was 1%. The postoperative length of stay was 1 day in 92% of the patients from all groups.

CONCLUSIONS

Avoiding the routine use of drains in redo thyroid surgery is safe and effective, it does not increase overall surgical morbidity, and it reduces the overall length of stay in hospital.

Management of the Neck in Well-Differentiated Thyroid Cancer

PURPOSE OF REVIEW

In this narrative review, we discuss the indications for elective and therapeutic neck dissections and the postoperative surveillance and treatment options for recurrent nodal disease in patients with well-differentiated thyroid cancer.

RECENT FINDINGS

Increased availability of advanced imaging modalities has led to an increased detection rate of previously occult nodal disease in thyroid cancer. Nodal metastases are more common in young patients, large primary tumors, specific genotypes, and certain histological types. While clinically evident nodal disease in the lateral neck compartments has a significant oncological impact, particularly in the older age group, microscopic metastases to the central or the lateral neck in well-differentiated thyroid cancer do not significantly affect outcome. As patients with clinically evident nodal disease are associated with worse outcomes, they should be treated surgically in order to reduce rates of regional recurrence and improve survival. The benefit of elective neck dissection remains unverified as the impact of microscopic disease on outcomes is not significant.

Nodule Size Effect on Diagnostic Performance of Ultrasonography and Computed Tomography for Papillary Thyroid Carcinoma

BACKGROUND

To compare the abilities of ultrasonography (US) and Computed Tomography (CT) to identify calcifications and to predict probability of malignancy for Papillary Thyroid Carcinoma (PTC) and Papillary Thyroid Microcarcinoma (PTMC).

METHODS

We reviewed 1008 cases of PTC/PTMC with calcifications reported by pre-operative US, CT, or post-operative pathology. The size of the thyroid nodule was obtained from the US report and the maximum diameter (d) was documented. According to the nodule size (d), the PTC and PTMC groups were each divided into two subgroups, as follows: large PTC group (d ≥ 2 cm), small PTC group (1 cm < d < 2 cm), large PTMC group (0.6 cm ≤ d ≤ 1 cm), and small PTMC group (d < 0.6 cm).

RESULTS

In the 1008 patients, the ratio of females to males was 2.29 and the mean age was 40.9 years (standard deviation: 11.7 years). Of the 1008 records, 92.8% were found to have calcifications according to the US report, while 50.4% showed calcifications according to the CT report. This difference between US and CT reports was statistically significant (p < 0.0005). The percentages of US reports showing calcifications were similar for all four PTC and PTMC subgroups (93.7%, 94.3%, 92.1%, and 85.1%, respectively; p = 0.052), while the percentages of CT reports showing calcifications were significantly different among the PTC and PTMC subgroups (62.3%, 52.2%, 45.4%, and 31.3%, respectively; p < 0.0005). As for the prediction of malignancy, US was superior to CT in all four subgroups (large PTC group: 97.1% vs. 54.1%, small PTC group: 94.8% vs. 42.9%, large PTMC group: 97.2% vs. 32.0%, small PTMC group: 95.5% vs. 14.9%; p < 0.0005 for all pairwise comparisons). No significant difference was observed in terms of the ability of US to predict the malignancy of PTC versus PTMC (p = 0.31), while CT showed significant superiority in diagnosing PTC versus PTMC (p < 0.0005). The predictive value of CT for PTC declined as the nodule size decreased (p < 0.05 for all pairwise comparisons).

CONCLUSION

Our results showed that US detected calcifications and predicted the malignancy of all nodule sizes of thyroid papillary carcinoma equally well, while the performance of CT declined with the reduction of nodule size.

Prophylactic central lymph node dissection informs the decision of radioactive iodine ablation in papillary thyroid cancer

BACKGROUND

Prophylactic central lymph node dissection (CLND) in papillary thyroid cancer (PTC) is controversial. We aimed to investigate if prophylactic CLND aids risk stratification and contributes to the decision for postoperative RAI ablation.

METHODS

Patients undergoing thyroidectomy for PTC and prophylactic CLND were identified from an endocrine surgical unit database. Pathology reports where reviewed for number and size of lymph nodes and patients stratified by risk according to the ATA guidelines.

RESULTS

426 patients were identified with PTC ≤4 cm and prophylactic CLND. 96 patients (23%) had central lymph node metastasis (CLNM) that qualified them for the intermediate risk group. In 17 patients (4%), the CLNM data led to upgrading independently of other histopathological characteristics. Correcting for multiple variables, CLNM was an independent factor contributing to RAI treatment.

CONCLUSION

Prophylactic CLND provides information to aid the selection of RAI ablation independent of primary cancer histology for risk stratification in 4% of patients. This benefit should be carefully balanced with the risk of CLND and patient treatment choice when deciding on management of PTC ≤4 cm.

Case for staged thyroidectomy

Recent modifications in the management of well-differentiated thyroid cancer have resulted in significant alterations in clinical approach. Utilizing a series of preoperative and postoperative risk factors involving both the patient and the disease pathology, we offer the term "staged thyroidectomy" to help organize these risk factors for patients and the endocrine team to optimize management. This approach is intended to incorporate our latest nuanced understanding of certain endocrine pathology and may serve to optimize patient outcomes.

Correlations of neck ultrasound and pathology in cervical lymph node of papillary thyroid carcinoma

Background: High-resolution sonography is becoming a method of choice for the detection and diagnosis of cervical lymph node metastasis in patients with papillary thyroid carcinoma (PTC). The purpose of this study is to assess the diagnostic accuracy of neck ultrasound (US) in the detection of lymph node metastases from PTC.Methods: Data for all patients with papillary thyroid cancers and preoperative neck US were reviewed retrospectively. The diagnostic accuracy of US was determined according to whether histologically confirmed cancer was present in surgical cervical lymph node specimens.Results: A total of 206 patients (149 central and 57 central and lateral lymph nodes dissection) were included. Their mean age was 56 years (14-88 years). Central and lateral lymph nodes were involved in 68% (n = 141 patients; 141/206) and 60% (n = 34 patients; 34/57) of cases, respectively. The sensitivity, specificity, positive predictive value and negative predictive value of US in predicting papillary thyroid carcinoma (PTC) metastasis in the central neck were 69%, 71%, 84% and 51% respectively, and in the lateral neck were 85%, 65%, 78% and 75% respectively.Conclusions: Preoperative neck US is a valuable tool in the detection of cervical lymph node metastases from papillary thyroid cancer and can provide reliable information to assist in surgical management.

Thyroid cancer neck lymph nodes metastasis: Meta-analysis of US and CT diagnosis

PURPOSE

Ultrasound (US) is the first imaging technique in the assessment of cervical lymph nodes metastasis (LNM) of papillary thyroid cancer (PTC) patients preoperatively. Computed tomography (CT) exerts an influence on surgical strategy especially for patients with lateral cervical LNM. This meta-analysis aimed at assessing the diagnostic values of US and CT in detecting the cervical LNM in thyroid cancer patients.

METHODS

Medline, Embase and Cochrane Library (CENTRAL) were retrieved up to 16^th Sep, 2019 for studies about comparison of the diagnostic performance between US and CT. The pooled sensitivity, specificity, positive likelihood ratio (LR), negative LR and diagnostic odds ratio (DOR), with each's 95 % CI were calculated.

RESULTS

A total of 5656 thyroid cancer patients in 10 studies were included. CT had a higher sensitivity in central (0.400 [0.385, 0.416] vs 0.284 [0.270, 0.298], P < 0.001), lateral (0.811 [0.778, 0.416] vs 0.758 [0.722, 0.792], P = 0.029) and the whole (0.664 [0.633, 0.694] vs 0.593 [0.561, 0.625], P = 0.002) compartments regions. US had a higher specificity in central (0.895 [0.885,0.903] vs 0.950 [0.944, 0.956], P < 0.001), lateral (0.84 [0.813,0.864] vs 0.88 [0.856, 0.901], P = 0.012) and the whole (0.834 [0.804,0.862] vs 0.911 [0.887, 0.932], P < 0.001) compartments regions.

CONCLUSIONS

US and CT performed poorly when trying to identify the presence of central LNM. CT has a higher sensitivity while US has a higher specificity for the assessment of central, lateral and the whole cervical LNM. Performing CT to detect the lateral cervical LNM will effectively reduce the rate of missed diagnosis and improve surgical planning. Both US and CT are needed for neck lymph nodes staging preoperatively owning to low sensitivities.