All thyroid ultrasound evaluations are not equal: sonographers specialized in thyroid cancer correctly label clinical N0 disease in well differentiated thyroid cancer

Semi-supervised graph convolutional networks for the domain adaptive recognition of thyroid nodules in cross-device ultrasound images

BACKGROUND

Ultrasound plays a critical role in the early screening and diagnosis of cancers. Although deep neural networks have been widely investigated in the computer-aided diagnosis (CAD) of different medical images, diverse ultrasound devices, and image modalities pose challenges for clinical applications, especially in the recognition of thyroid nodules having various shapes and sizes. More generalized and extensible methods need to be developed for the cross-devices recognition of thyroid nodules.

PURPOSE

In this work, a semi-supervised graph convolutional deep learning framework is proposed for the domain adaptative recognition of thyroid nodules across several ultrasound devices. A deep classification network, trained on a source domain with a specific device, can be transferred to recognize thyroid nodules on the target domain with other devices, using only few manual annotated ultrasound images.

METHODS

This study presents a semi-supervised graph-convolutional-network-based domain adaptation framework, namely Semi-GCNs-DA. Based on the ResNet backbone, it is extended in three aspects for domain adaptation, that is, graph convolutional networks (GCNs) for the connection construction between source and target domains, semi-supervised GCNs for accurate target domain recognition, and pseudo labels for unlabeled target domains. Data were collected from 1498 patients comprising 12 108 images with or without thyroid nodules under three different ultrasound devices. Accuracy, Sensitivity and Specificity were used for the performance evaluation.

RESULTS

The proposed method was validated on six groups of data for a single source domain adaptation task, the mean Accuracy was 0.9719 ± 0.0023, 0.9928 ± 0.0022, 0.9353 ± 0.0105, 0.8727 ± 0.0021, 0.7596 ± 0.0045, 0.8482 ± 0.0092, which achieved better performance in comparison with the state-of-the-art. The proposed method was also validated on three groups of multiple source domain adaptation tasks. In particular, when using X60 and HS50 as the source domain data, and H60 as the target domain, it can achieve the Accuracy of 0.8829 ± 0.0079, Sensitivity of 0.9757 ± 0.0001, and Specificity of 0.7894 ± 0.0164. Ablation experiments also demonstrated the effectiveness of the proposed modules.

CONCLUSION

The developed Semi-GCNs-DA framework can effectively recognize thyroid nodules on different ultrasound devices. The developed semi-supervised GCNs can be further extended to the domain adaptation problems for other modalities of medical images.

A Novel Thyroid Ultrasound Proficiency Metric Designed Through a Multidisciplinary Delphi Approach

BACKGROUND

Thyroid ultrasounds extend surgeons' outpatient capabilities and are essential for operative planning. However, most residents are not formally trained in thyroid ultrasound. The purpose of this study was to create a novel thyroid ultrasound proficiency metric through a collaborative Delphi approach.

METHODS

Clinical faculty experienced in thyroid ultrasound participated on a Delphi panel to design the thyroid Ultrasound Proficiency Scale (UPS-Thyroid). Participants proposed items under the categories of Positioning, Technique, Image Capture, Measurement, and Interpretation. In subsequent rounds, participants voted to retain, revise, or exclude each item. The process continued until all items had greater than 70% consensus for retention. The UPS-Thyroid was pilot tested across 5 surgery residents with moderate ultrasound experience. Learning curves were assessed with cumulative sum.

RESULTS

Three surgeons and 4 radiologists participated on the Delphi panel. Following 3 iterative Delphi rounds, the panel arrived at >70% consensus to retain 14 items without further revisions or additions. The metric included the following items on a 3-point scale for a maximum of 42 points: Positioning (1 item), Technique (4 items), Image Capture (2 items), Measurement (2 items), and Interpretation (5 items). A pilot group of 5 residents was scored against a proficiency threshold of 36 points. Learning curve inflection points were noted at between 4 to 7 repetitions.

CONCLUSIONS

A multidisciplinary Delphi approach generated consensus for a thyroid ultrasound proficiency metric (UPS-Thyroid). Among surgery residents with moderate ultrasound experience, basic proficiency at thyroid ultrasound is feasible within 10 repetitions.

Surgeon-performed ultrasound changes surgical management in patients with thyroid cancer

BACKGROUND

A comprehensive neck ultrasound (US) is essential in the operative planning of patients with thyroid disease. Recent literature has shown surgeon-performed US (SUS) can be more accurate than radiology-performed US for the purpose of surgical planning. Missed findings on radiology-performed ultrasound may lead to inadequate surgical management.

METHODS

A retrospective cohort study of patients undergoing total thyroidectomy with lateral neck dissection for thyroid cancer, with both radiology-performed US and SUS performed by a Head and Neck surgeon. Ultrasound findings and adherence to American Thyroid Association (ATA) guidelines were compared, and changes in management based on SUS findings were identified.

RESULTS

A total of 26 patients who underwent total thyroidectomy with lateral neck dissection met the inclusion criteria. Preconsultation US investigations fulfilled criteria as recommended by the American Thyroid Association (ATA) guidelines in 57.7%% of cases. The central and lateral neck compartments were assessed in 57.7% and 84.6% of preconsultation US investigations respectively. Central and lateral metastatic neck metastases were incorrectly reported or not reported in 78.6% and 42.3% of cases. The SUS findings prompted a change in surgical management in 65.4% of cases.

CONCLUSION

SUS changed surgical management in two thirds (65.4%) of patients. Reliance on radiology-performed ultrasound alone may result in incorrect staging. Awareness of the additional benefits of SUS is important for surgeons treating patients with thyroid disease to prevent inadequate surgery being performed.

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.

Can Serum Thyroglobulin Levels Help to Identify the Involved Neck Compartment of Differentiated Thyroid Carcinoma?

We aimed to evaluate the predictive ability of serum thyroglobulin (Tg) levels on the localization of the metastatic lymph node compartments in locoregional metastases of papillary thyroid cancer (PTC). This retrospective study included 143 patients who underwent neck dissections for a total of 172 for persistent/recurrent locoregional PTC. They were grouped according to the localization of lymph node metastasis (LNM): Central (C-LNM), Lateral (L-LNM), both central and lateral LNM (C+L LNM). To confirm that the Tg cutoff discriminated LNM localizations, the sample was categorized as suppressed (<0.1 mU/l) or non-suppressed (>0.1 mU/l) according to TSH and ROC analysis. Mixed-effects models were used to investigate the effect of LNM localization on Tg levels and to eliminate the confounding effects of TSH, tumor burden (defined as the number and the largest diameter of LNM), and RAI. Mean Tg levels were 1.43 μg/l for C-LNM (n=47), 3.7 μg/l for L-LNM (n=99), and 8.60 μg/l for C+L LNM (n=26). Independent of TSH, tumor burden and RAI, the mean Tg levels of L-LNM and C+L LNM groups were not significantly different, while that of C-LNM was significantly lower than those of L-LNM and C+L LNM. To discriminate C-LNM from L-LNM and C+L LNM in patients with TSH>0.1 mU/l, the optimal cutoff for Tg was 1.05 μg/l (sensitivity=74.7%, specificity=70.4%, PPV=87.7%). L-LNM increases serum Tg levels more than C-LNM in persistent/recurrent locoregional nodal disease of PTC. Tg above 1.05 μg/l may indicate lateral LNM. Tg may be an important marker for the localization of LNM in the neck.

A nomogram to predict lateral lymph node metastases in lateral neck in patients with medullary thyroid cancer

BACKGROUND

Medullary thyroid cancer (MTC) can only be cured by surgery, but the management of lateral lymph nodes is controversial, especially for patients with cN0+cN1a. To address this challenge, we developed a multivariate logistic regression model to predict lateral lymph node metastases (LNM).

METHODS

We retrospectively collected clinical data from 124 consecutive MTC patients who underwent initial surgery at our institution. The data of 82 patients (from 2010 to 2018) and 42 patients (from January 2019 to November 2019) were used as the training set for building the model and as the test set for validating the model, respectively.

RESULTS

In the training group, the multivariate analyses indicated that male and MTC patients with higher preoperative basal calcitonin levels were more likely to have lateral LNM (P = 0.007 and 0.005, respectively). Multifocal lesions and suspected lateral LNM in preoperative ultrasound (US) were independent risk factors (P = 0.032 and 0.002, respectively). The identified risk factors were incorporated into a multivariate logistic regression model to generate the nomogram, which showed good discrimination (C-index = 0.963, 95% confidence interval [CI]: 0.9286-0.9972). Our model was validated with an excellent result in the test set and even superior to the training set (C-index = 0.964, 95% CI: 0.9121-1.000).

CONCLUSION

Higher preoperative basal calcitonin level, male sex, multifocal lesions, and lateral lymph node involvement suspicion on US are risk factors for lateral LNM. Our model and nomogram will objectively and accurately predict lateral LNM in patients with MTC.

A Randomized Controlled Clinical Trial: No Clear Benefit to Prophylactic Central Neck Dissection in Patients With Clinically Node Negative Papillary Thyroid Cancer

OBJECTIVE

The aim of this prospective randomized-controlled trial was to evaluate the risks/benefits of prophylactic central neck dissection (pCND) in patients with clinically node negative (cN0) papillary thyroid cancer (PTC).

BACKGROUND

Microscopic lymph node involvement in patients with PTC is common, but the optimal management is unclear.

METHODS

Sixty patients with cN0 PTC were randomized to a total thyroidectomy (TT) or a TT+ pCND. All patients received postoperative laryngoscopies and standardized radioiodine treatment. Thyroglobulin (Tg) levels and/or neck ultrasounds were performed at 6 weeks, 6 months, and 1 year.

RESULTS

Tumors averaged 2.2 ± 0.2 cm and 11.9% had extra-thyroidal extension. Thirty patients underwent a pCND and 27.6% had positive nodes (all ≤6 mm). Rates of postoperative PTH < 10 (33.3% vs 24.1%, P = 0.57) and transient nerve dysfunction (13.3% vs 10.3%, P = 1.00) were not significantly different between groups. Six weeks after surgery, both TT and TT + pCND were equally likely to achieve a Tg < 0.2 (54.5% vs 66.7%, P = 0.54) and/or a stimulated Tg (sTg) <1 (59.3% vs 64.0%, P = 0.78). At 1 year, rates of Tg < 0.2 (88.9% vs 90.0%, P = 1.00) and sTg < 1 (93.8% vs 92.3%, P = 1.00) remained similar between groups. Neck ultrasounds at 1 year were equally likely to be read as normal (85.7% in TT vs 85.1% in pCND, P = 1.00).

CONCLUSIONS

cN0 PTC patients treated either with TT or TT + pCND had similar complication rates after surgery. Although microscopic nodes were discovered in 27.6% of pCND patients, oncologic outcomes were comparable at 1 year.

Improving Diagnostic Performance for Thyroid Nodules Classified as Bethesda Category III or IV: How and by Whom Ultrasonography Should be Performed

BACKGROUND

The purpose of this prospective study is to evaluate if the association of Bethesda system and a 3-categories Ultrasonography (US) risk stratification system proposed by the American Association of Clinical Endocrinologists/American College of Endocrinology/Associazione Medici Endocrinologi improves the performance of cytology alone in III or IV categories and if further variables such as US provider (radiologist; endocrinologist, or endocrine surgeon both coming from a dedicated team) influence the accuracy of the diagnostic.

METHODS

570 consecutive patients with complete clinical records, affected by Bethesda III or IV nodules, have been addressed to two public referral surgical centers of Western Sicily. Age, sex, autoimmunity, nodule size, and US provider were recorded. Fisher's exact test was used for the univariate analysis; Odd's ratios were calculated for the multivariate analysis.

RESULTS

248 patients had malignancy at histology, 322 were benign. The mean age was 52 years for the malignancy group and 58 y for the benign group (P < 0.001). At univariate analysis, autoimmunity was correlated with benign group (P < 0.001), and US risk 2 and 3 were correlated with malignancy (nearly 10-folds, P < 0.001); In addition, no difference was found concerning nodule size. At multivariate analysis, US risk 2 and 3 were strong predictors of malignancy (P < 0.0001) especially if cytology was Bethesda IV; endocrinologist and surgeon were more accurate in predicting malignancy compared with the radiologist (P < 0.01).

CONCLUSIONS

In the context of indeterminate nodules, the American College of Endocrinology/American Association of Clinical Endocrinologists/Associazione Medici Endocrinologi US risk stratification system strongly improves the results of Bethesda system especially when performed from dedicated endocrinologist or endocrine surgeon.

Physician Confidence in Neck Ultrasonography for Surveillance of Differentiated Thyroid Cancer Recurrence

IMPORTANCE

Neck ultrasonography, a mainstay of long-term surveillance for recurrence of differentiated thyroid cancer (DTC), is routinely used by endocrinologists, general surgeons, and otolaryngologists; however, physician confidence in their ability to use ultrasonography to identify lymph nodes suggestive of cancer recurrence remains unknown.

OBJECTIVE

To evaluate physicians' posttreatment surveillance practices for DTC recurrence, specifically their use of and confidence in ultrasonography.

DESIGN, SETTING, AND PARTICIPANTS

Cross-sectional study of 448 physicians in private and academic hospitals who completed a survey on DTC posttreatment practices from October 2018 to August 2019 (response rate, 69%) and self-reported involvement in long-term surveillance for thyroid cancer recurrence. Physicians were identified by patients affiliated with the Surveillance, Epidemiology, and End Results Program registries in Georgia State and Los Angeles County. Of the respondents, 320 physicians who reported involvement with DTC surveillance were included in the analysis.

MAIN OUTCOMES AND MEASURES

Physician-reported long-term surveillance practices for DTC, including frequency of use and level of confidence in ultrasonography for detecting lymph nodes suggestive of cancer recurrence.

RESULTS

In the cohort of 320 physicians who reported involvement with DTC surveillance, 186 (60%) had been in practice for 10 years to less than 30 years; 209 (68%) were White; and 212 (66%) were men. The physicians included 170 (56%) endocrinologists, 67 (21%) general surgeons, and 75 (23%) otolaryngologists. Just 84 (27%) physicians reported personally performing bedside ultrasonography. Only 57 (20%) had high confidence (rated quite or extremely confident) in their ability to use bedside ultrasonography to identify lymph nodes suggestive of recurrence; 94 (33%) did not report high confidence in either their ability or a radiologist's ability to use ultrasonography to detect recurrence. Higher confidence in ultrasonography was associated with the general surgery subspecialty (odds ratio [OR], 5.7; 95% CI, 2.2-14.4; reference endocrinology) and with treating a higher number of patients per year (>50 patients: OR, 14.4; 95% CI, 4.4-47.4; 31-50 patients: OR, 8.4; 95% CI, 2.6-26.7; 11-30 patients: OR, 4.3; 95% CI, 1.5-12.1; reference 0-10 patients).

CONCLUSIONS AND RELEVANCE

Given the importance of neck ultrasonography in long-term surveillance for thyroid cancer, these findings of physicians' low confidence in their own ability and that of radiologists to use ultrasonography to detect recurrence point to a major obstacle to standardizing long-term DTC surveillance practices.

Preoperative Serum Calcitonin and Its Correlation with Extent of Lymph Node Metastasis in Medullary Thyroid Carcinoma

Simple Summary

Surgery is the only curative treatment for medullary thyroid carcinoma (MTC), but the initial surgical extent is still controversial. We examined whether the preoperative serum calcitonin level reflects the extent of lymph node metastasis (LNM), and therefore might be used to predict the optimal initial surgical extent for MTC. Furthermore, positive and negative likelihood ratios for preoperative serum calcitonin were calculated for calcitonin concentration categories, revealing that serum calcitonin levels can be of diagnostic value and might be applicable to surgical decision-making.

Abstract

The optimal initial surgical extent for medullary thyroid carcinoma (MTC) remains controversial. Previous studies on serum calcitonin are limited to reporting the calcitonin threshold according to anatomical disease burden. Here, we evaluated whether preoperative calcitonin levels can be used to predict optimal surgical extent. We retrospectively reviewed the 170 patients with MTC at a tertiary Korean hospital from 1994 to 2019. We extracted data on preoperative calcitonin level, primary tumor size and the number and location of lymph node metastases (LNMs). To evaluate disease extent, we divided the patients into five groups: no LNM, central LNM, ipsilateral lateral LNM, contralateral lateral LNM, and distant metastasis. We calculated the positive and negative likelihood ratios (LRs) for multiple categories of preoperative calcitonin levels. Preoperative calcitonin level positively correlated with primary tumor size (rho = 0.744, p < 0.001) and LNM number (rho = 0.537, p < 0.001). Preoperative calcitonin thresholds of 20, 200, and 500 pg/mL were associated with the presence of ipsilateral lateral LNM, contralateral lateral LNM, and distant metastasis, respectively. The negative LRs were 0.1 at a preoperative calcitonin cut-off of 100 pg/mL in the central LNM, 0.18 at a cut-off of 300 pg/mL in the ipsilateral lateral LNM, and 0 at a cut-off of 300 pg/mL in the contralateral lateral LNM. The preoperative calcitonin level correlates with disease extent and has diagnostic value for predicting LNM extent. Our results suggest that the preoperative calcitonin level can be used to determine optimal initial surgical extent.

Patient Report of Recurrent and Persistent Thyroid Cancer

Background: Despite the excellent survival of most patients with differentiated thyroid cancer (DTC), recurrent and persistent disease remain major concerns for physicians and patients. However, studies on patient report of recurrent and persistent disease are lacking. Methods: Between February 1, 2017, and October 31, 2018, we surveyed eligible patients who were diagnosed with DTC between 2014 and 2015 from the Georgia and Los Angeles Surveillance, Epidemiology, and End Results cancer registries (N = 2632; response rate, 63%). Patients who reported current disease status were included in this study (n = 2454). Patient-reported data were linked to registry data. A multivariable, multinomial logistic regression analysis was conducted to determine patient and tumor characteristics associated with recurrent and persistent thyroid cancer. Quality of life was evaluated using the Patient-Reported Outcomes Measurement Information System-Global Health v1.2 questionnaire. Meaningful change in global health was defined as a minimal difference of a half standard deviation or 5 points compared with the mean (T score = 50) of a sample population matching the United States 2000 General Census. Results: Of the 2454 patients completing the survey, 95 (4.1%) reported recurrent disease and 137 (5.8%) reported persistent disease. In multinomial analyses, T3/T4 classification and cervical lymph node involvement (N1) were associated with both report of recurrent (adjusted relative risk ratio [RRR] 1.99, 95% confidence interval [CI 1.16-3.42]; adjusted RRR 2.03 [CI 1.29-3.21], respectively) and persistent disease (adjusted RRR 3.48 [CI 1.96-6.20]; adjusted RRR 3.56 [CI 2.41-5.24], respectively). Additionally, Hispanic ethnicity was associated with report of recurrent disease (adjusted RRR 1.99 [CI 1.23-3.24]). Regarding quality of life, the median scores in patients with persistent disease met criteria for meaningful change in global physical health (T-score = 44.9) and global mental health (T-score = 43.5) when compared with the general population norms. Median scores in patients with cured or recurrent disease did not meet criteria for meaningful change. Conclusions: Patient report is a reasonable method of assessing recurrent and persistent disease. Impact on quality of life is more marked for patients with reported persistent disease. Our findings will help personalize treatment and long-term follow-up in these patients.

Preoperative Serum Thyroglobulin and Its Correlation with the Burden and Extent of Differentiated Thyroid Cancer

Lymph node metastasis (LNM) in differentiated thyroid cancer (DTC) is usually detected with preoperative ultrasonography; however, this has limited sensitivity for small metastases, and there is currently no predictive biomarker that can help to inform the extent of surgery required. We evaluated whether preoperative serum thyroglobulin levels can predict tumor burden and extent. We retrospectively reviewed the clinical records of 4029 DTC cases diagnosed and treated at a Samsung Medical Center between 1994 and 2016. We reviewed primary tumor size, number and location of LNM, and presence of distant metastases to reveal relationships between tumor burden and extent and preoperative serum thyroglobulin levels. We found a linear association between increasing preoperative thyroglobulin levels, the size of the primary tumor, and the number of LNM (r = 0.34, p < 0.001, r = 0.20, p < 0.001, respectively). Tumor extent also increased with each decile of increasing preoperative thyroglobulin level (r = 0.18, p < 0.001). Preoperative thyroglobulin levels of 13.15 ng/mL, 30.05 ng/mL, and 62.9 ng/mL were associated with the presence of ipsilateral lateral LNM, contralateral lateral LNM, and distant metastasis, respectively. Our results suggest that preoperative measurement of serum thyroglobulin may help to predict LNM and help to tailor surgery.

Preoperative Computed Tomography Changes Surgical Management for Clinically Low-Risk Well-Differentiated Thyroid Cancer

BACKGROUND

In the current guidelines for differentiated thyroid cancer (DTC), computed tomography (CT) of the neck has a limited role. The authors hypothesized that adding CT to the workup of clinically low-risk DTC size 4 cm or smaller changes the surgical management for a portion of patients due to detection of clinically significant lymph node metastases not located by ultrasound of the neck.

METHODS

A prospective cohort of DTC patients at an academic referral center between 2012 and 2016 was reviewed. All the patients with fine-needle aspiration cytopathology results suspicious for malignancy or malignant tumor (Bethesda category 5 or 6, respectively) underwent CT before surgery. Clinically low-risk DTC patients were selected if they had a tumor diameter of 4 cm or less and no evidence for local invasion or suspicious lymph nodes seen on ultrasound. Outcomes focused on alteration of the surgical plan based on CT and correlation with pathology.

RESULTS

The CT findings for 25 (22.5%) of 111 patients with clinically low-risk DTC led to a change in surgical management. Of these 25 patients, 16 (14.4% of the entire cohort) benefited due to the removal of clinically significant lymph node disease not seen on ultrasound. Categorization of the group that had a change in management showed that 6 (85.7%) of 7 lateral neck dissections and 10 (55.6%) of 18 central neck dissections (CND) harbored metastatic nodes larger than 2 mm.

CONCLUSIONS

In the group with clinically low-risk DTC, CT changed surgical management for a substantial number of the patients with clinically significant nodal disease not detected by ultrasound. This highlights the fact that in certain practice settings, adding CT to the preoperative staging may be favorable for the detection of nodal metastasis.

Characterization of laser ultrasound source signals in biological tissues for imaging applications

Short optical pulses emitted from a tunable Q-switched laser (800 to 2000 nm) generate laser ultrasound (LUS) signals at the surface of biological tissue. The LUS signal's acoustic frequency content, dependence on sample type, and optical wavelength are observed in the far field. The experiments yield a reference dataset for the design of noncontact LUS imaging systems. Measurements show that the majority of LUS signal energy in biological tissues is within the 0.5 and 3 MHz frequency bands and the total acoustic energy generated increases with the optical absorption coefficient of water, which governs tissue optical absorption in the infrared range. The experimental results also link tissue surface roughness and acoustic attenuation with limited LUS signal bandwidth in biological tissue. Images constructed using 810-, 1064-, 1550-, and 2000-nm generation laser wavelengths and a contact piezoelectric receiver demonstrates the impact of the generation laser wavelength on image quality. A noncontact LUS-based medical imaging system has the potential to be an effective medical imaging device. Such a system may mitigate interoperator variability associated with current medical ultrasound imaging techniques and expand the scope of imaging applications for ultrasound.

Incomplete Thyroid Ultrasound Reports for Patients With Thyroid Nodules: Implications Regarding Risk Assessment and Management

OBJECTIVE

The purpose of this study was to determine the completeness of thyroid ultrasound (US) reports, assess for differences in report interpretation by clinicians, and evaluate for implications in patient care.

MATERIALS AND METHODS

We retrospectively reviewed thyroid US examinations performed between January and June 2013 in Nova Scotia, Canada. Baseline examinations that identified a nodule were evaluated for 10 reporting elements. Reports that lacked a comment regarding malignancy risk or a recommendation for biopsy were considered unclassified and were graded by three clinical specialists in accordance with the 2015 American Thyroid Association management guidelines. Interrater agreement was assessed using the Cohen kappa statistic. A radiologist reviewed the images of unclassified nodules, and on the basis of radiologic grading, biopsy rates and pathologic findings were compared between nodules that did and did not warrant biopsy.

RESULTS

Of 971 first-time thyroid US studies, 478 detected a nodule. The number of reports lacking a comment on the 10 elements ranged from 154 to 433 (32-91%). A total of 222 nodules (46%) were unclassified, and agreement in assigned grading by the clinical specialists was very poor (κ = 0.07; p < 0.05). According to radiologist grading, only 57 of 127 biopsies were performed on nodules that warranted biopsy, and 16 of 95 biopsies were performed unnecessarily. On the basis of the three clinical specialists' interpretation, 10, 31, and 33 reports were considered too incomplete to assign a grade; 40, 10, and four biopsies would have been unnecessarily ordered; and zero, three, and four cancers would have been missed.

CONCLUSION

There is widespread underreporting of established elements in thyroid US reports, and this causes confusion and discrepancy among clinical specialists regarding the risk of malignancy and the need for biopsy.

Decision making for the central compartment in differentiated thyroid cancer

The central compartment is a common site for nodal spread from differentiated thyroid carcinoma, often occurring in patients without clinical or ultrasonographic (US) evidence of neck lymph node metastasis (cN0). However, the role of elective central compartment neck dissection (CND) among patients with DTC remains controversial. We performed a systematic literature review, also including review of international guidelines, with discussion of anatomic and technical aspects, as well as risks and benefits of performing elective CND. The recent literature does not uniformly support or refute elective CND in patients with DTC, and therefore an individualized approach is warranted which considers individual surgeon experience, including individual recurrence and complication rates. Patients (especially older males) with large tumors (>4 cm) and extrathyroidal extension are more likely to benefit from elective CND, but elective CND also increases risk for hypoparathyroidism and recurrent nerve injury, especially when operated by low-volume surgeons. Individual surgeons who perform elective CND must ensure the number of central compartment dissections needed to prevent one recurrence (number needed to treat) is not disproportionate to their individual number of central compartment dissections per related complication (number needed to harm).

Active Surveillance for Papillary Thyroid Microcarcinoma: Challenges and Prospects

Active surveillance (AS) can be considered as an alternative to immediate surgery in low-risk papillary thyroid microcarcinoma (PTMC) without clinically apparent lymph nodes, gross extrathyroidal extension (ETE), and/or distant metastasis according to American Thyroid Association. However, in the past AS has been controversial, as evidence supporting AS in the management of PTMC was scarce. The most prominent of these controversies included, the limited accuracy and utility of ultrasound (US) in the detection of ETE, malignant lymph node involvement or the advent of novel lymph node malignancy during AS, and disease progression. We summarized publications and indicated: (1) US, performer-dependent, could not accurately diagnose gross ETE or malignant lymph node involvement in PTMC. However, the combination of computed tomography and US provided more accurate diagnostic performance, especially in terms of selection sensitivity. (2) Compared to immediate surgery patients, low-risk PTMC patients had a slightly higher rate of lymph node metastases (LNM), although the overall rate for both groups remained low. (3) Recent advances in the sensitivity and specificity of imaging and incorporation of diagnostic biomarkers have significantly improved confidence in the ability to differentiate indolent vs. aggressive PTMCs. Our paper reviewed current imagings and biomarkers with initial promise to help select AS candidates more safely and effectively. These challenges and prospects are important areas for future research to promote AS in PTMC.

Importance of surgeon-performed ultrasound in the preoperative nodal assessment of patients with potential thyroid malignancy

INTRODUCTION

A comprehensive cervical ultrasound evaluation is essential in the operative planning of patients with thyroid disease. Reliance on radiographic reports alone may result in incomplete operative management as pathologic lymph nodes are often not palpable and evaluation of the lateral neck is not routine. This study examined the role of surgeon-performed ultrasound in the evaluation of patients who underwent lateral neck dissection for thyroid cancer.

METHODS

We conducted a retrospective review of a prospectively maintained database of patients who underwent therapeutic lymph node dissection for thyroid cancer between 2001 and 2016 at our tertiary referral center. All patients had surgeon-performed ultrasound preoperatively by 1 of 7 endocrine surgeons. These findings were compared with prereferral imaging studies to determine the value of surgeon-performed ultrasound to their overall treatment.

RESULTS

Of 92 patients who underwent thyroidectomy with lateral neck dissection, 97% had prereferral imaging of the neck (ultrasonography, computed tomography, positron emission tomography). Of these patients, nodal disease was suggested by computed tomography scanning in 70.8% and by ultrasonography in 54%. Of all patients, 45% had positive lateral neck nodes detected only on surgeon-performed ultrasound despite prior neck imaging. Nodal disease was identified in 50% of patients with only 1 study and 50% of patients with greater than 1 study before surgeon-performed ultrasound. Of patients with nodes detected by surgeon-performed ultrasound, only 67% had a prereferral diagnosis of thyroid cancer.

CONCLUSIONS

Our data demonstrate that reliance on standard preoperative imaging alone would have led to an incorrect initial operation in 45% of our patients. Awareness of the limitations of prereferral imaging is important for surgeons treating patients with thyroid and parathyroid disease. Surgeon-performed ultrasound is a useful tool in the diagnosis and accurate staging of patients.

Back so soon? Is early recurrence of papillary thyroid cancer really just persistent disease?

BACKGROUND

Papillary thyroid carcinoma has excellent survival, yet recurrence remains a challenge. We sought to determine the proportion of reoperations performed for persistent, rather than truly recurrent, disease.

METHODS

We conducted a retrospective review of a prospectively maintained database. Patients with papillary thyroid carcinoma who underwent reoperation for disease from 2000-2016 were included. We defined recurrence as disease that developed after a patient had an undetectable thyroglobulin and a negative ultrasonography within 1 year of operation.

RESULTS

A total of 69 patients underwent 92 reoperations. On initial pathology, mean tumor size was 2.6 cm, 51% were multifocal, and 42% had extrathyroidal extension. Half (46%) of the patients underwent a central/lateral neck dissection at the initial operation, and 77% were treated with postoperative radioactive iodine. The median time to first reoperation was 21 months (range, 1-292), and 42% occurred within 1 year. Only 3 operations met criteria for true "recurrence," while 71 operations were categorized as persistent disease.

CONCLUSION

Many reoperations for papillary thyroid carcinoma are for management of persistent disease. More than half of the patients required reoperation within the first 2 years, which suggests strongly that improvements in the preoperative assessment and adequacy of initial operative therapy need to be made to improve the care of patients with thyroid cancer.

GAUGING THE EXTENT OF THYROIDECTOMY FOR INDETERMINATE THYROID NODULES: AN ONCOLOGIC PERSPECTIVE

OBJECTIVE

Increasing emphasis is being placed on appropriateness of care and avoidance of over- and under-treatment. Indeterminate thyroid nodules (ITNs) present a particular risk for this problem because cancer found via diagnostic lobectomy (DL) often requires a completion thyroidectomy (CT). However, initial total thyroidectomy (TT) for benign ITN results in lifelong thyroid hormone replacement. We sought to measure the accuracy and factors associated with the extent of initial thyroidectomy for ITN.

METHODS

We queried a single institution thyroid surgery database for all adult patients undergoing an initial operation for ITN. Multivariate logistic regression identified factors associated with either oncologic under- or overtreatment at initial operation.

RESULTS

There were 639 patients with ITN. The median age was 52 (range, 18 to 93) years, 78.4% were female, and final pathology revealed a cancer >1 cm in 24.7%. The most common cytology was follicular neoplasm (45.1%) followed by Hürthle cell neoplasm (20.2%). CT or initial oncologic undertreatment was required in 58 patients (9.3%). Excluding those with goiters, 19.0% were treated with TT for benign final pathology. Multivariate analysis failed to identify any factor that independently predicted the need for CT. Female gender was associated with TT in benign disease (odds ratio [OR], 2.1; 95% confidence interval [CI], 1.0 to 4.5; P = .05). Age >45 years predicted correct initial use of DL (OR, 2.6; 95% CI, 1.2 to 5.7; P = .02). Suspicious for papillary thyroid carcinoma (OR, 5.7; 95% CI, 2.1 to 15.3; P<.01) and frozen section (OR, 9.7; 95% CI, 2.5 to 38.6; P<.01) were associated with oncologically appropriate initial TT. The highest frequency of CT occurred in patients with follicular lesion of undetermined significance (11.6%). TT for benign final pathology occurred most frequently in patients with a Hürthle cell neoplasm (24.8%).

CONCLUSION

In patients with ITN, nearly 30% received an inappropriate extent of initial thyroidectomy from an oncologic standpoint. Tools to pre-operatively identify both benign and malignant disease can assist in the complex decision making to gauge the proper extent of initial surgery for ITN.

ABBREVIATIONS

ATA = American Thyroid Association AUS = atypia of undetermined significance CI = confidence interval CT = completion thyroidectomy FLUS = follicular lesion of undetermined significance ITN = indeterminate thyroid nodule OR = odds ratio PTC = papillary thyroid carcinoma TT = total thyroidectomy.

Bethesda Category III, IV, and V Thyroid Nodules: Can Nodule Size Help Predict Malignancy?

BACKGROUND

The association of tumor size with malignancy in thyroid nodules with indeterminate cytology (atypia of undetermined significance [AUS]/follicular lesion of undetermined significance [FLUS], suspicious for follicular neoplasm [SFN]/Hürthle cell neoplasm [HCN], and suspicious for malignancy [SM]) has not been clearly studied.

STUDY DESIGN

We retrospectively identified 1,104, patients who underwent thyroid FNA and subsequent thyroidectomy. Patients with indeterminate cytology were reviewed. The size of the nodule was determined by ultrasound. Malignancy was confirmed by final histology. Logistic regression modeling was performed to determine if nodule size was associated with malignancy.

RESULTS

There were 461 (42%) patients who had indeterminate cytology by FNA. The median nodule size of all indeterminate lesions was 2.1 cm (range 0.5 to 10 cm). The median nodule size for AUS/FLUS was 2.1 cm (range 0.7 to 8 cm), for SFN was 2.4 cm (range 0.5 to 10 cm), for HCN was 2.2 cm (range 0.5 to 9.3 cm), and for SM was 1.6 cm (range 0.5 to 6 cm). On final histology, 121 (28%) index lesions were malignant (AUS 23%; FLUS 14%; SFN 22%; HCN 25%; SM 69%). On logistic regression, nodule size was not associated with increased odds of malignancy in all lesions with indeterminate cytology (odds ratio [OR] 0.83; 95% CI 0.76 to 1.00; p = 0.051). Nodule size was not associated with malignancy in the index nodule of AUS/FLUS, SFN, or SM lesions. Increased nodule size was associated with malignancy in HCN lesions (OR 2.17; 95% CI 1.16 to 4.04; p = 0.01).

CONCLUSIONS

The findings of this study suggest that larger HCN nodules are more likely to be malignant. Nodule size alone was not predictive of malignancy in patients with AUS/FLUS, SFN, or SM. Clinical picture, institution-specific malignancy rates, and molecular testing continue to be important factors guiding treatment.

Why Thyroid Surgeons Are Frustrated with Radiologists: Lessons Learned from Pre- and Postoperative US

Optimal treatment of thyroid cancer is highly dependent on accurate staging of the extent of disease at presentation. Preoperative ultrasonography (US) is the most sensitive method for detecting metastatic lymph nodes and is recommended as part of the standard preoperative workup. Missed findings on preoperative scans may lead to understaging and inadequate surgical management, which subsequently predispose these patients to residual disease postoperatively and a higher risk for recurrence, possibly requiring repeat surgery. Traditionally, thyroid US for pre- and postoperative staging has been performed by radiologists. However, there is a growing trend away from radiologist-performed US in favor of surgeon-performed US. Recent surgical and endocrinology literature has shown that, when compared with surgeon-performed US, radiologist-performed preoperative staging US is less accurate and is inadequate for presurgical planning, with higher local recurrence rates. This review highlights the importance of accurate preoperative US for patients with differentiated thyroid cancer, with specific attention to deficiencies that exist in general radiology department thyroid US reports. We present a standardized approach to neck US reporting that incorporates the newly updated 2015 recommendations from the American Thyroid Association and also addresses the pertinent questions for thyroid surgeons. By ensuring comprehensive preoperative assessment and improving thyroid US reporting, we seek to improve patient access to optimized care. ^©RSNA, 2016.

Diagnostic, therapeutic and health-care management protocol in thyroid surgery: a position statement of the Italian Association of Endocrine Surgery Units (U.E.C. CLUB)

PURPOSE

The diagnostic, therapeutic and health-care management protocol (Protocollo Gestionale Diagnostico-Terapeutico-Assistenziale, PDTA) by the Association of the Italian Endocrine Surgery Units (U.E.C. CLUB) aims to help treat the patient in a topical, rational way that can be shared by health-care professionals.

METHODS

This fourth consensus conference involved: a selected group of experts in the preliminary phase; all members, via e-mail, in the elaboration phase; all the participants of the XI National Congress of the U.E.C. CLUB held in Naples in the final phase. The following were examined: diagnostic pathway and clinical evaluation; mode of admission and waiting time; therapeutic pathway (patient preparation for surgery, surgical treatment, postoperative management, management of major complications); hospital discharge and patient information; outpatient care and follow-up.

RESULTS

A clear and concise style was adopted to illustrate the reasons and scientific rationales behind behaviors and to provide health-care professionals with a guide as complete as possible on who, when, how and why to act. The protocol is meant to help the surgeon to treat the patient in a topical, rational way that can be shared by health-care professionals, but without influencing in any way the physician-patient relationship, which is based on trust and clinical judgment in each individual case.

CONCLUSIONS

The PDTA in thyroid surgery approved by the fourth consensus conference (June 2015) is the official PDTA of U.E.C. CLUB.