Diagnosis of neck recurrences in patients with differentiated thyroid carcinoma

Contribution of neck ultrasonography to patient management in patients with differentiated thyroid carcinoma with excellent response to therapy

PURPOSE

To assess the contribution of intense neck ultrasonography (US) follow-up in the clinical management of differentiated thyroid carcinoma (DTC) patients with the American Thyroid Association (ATA) low-intermediate-risk of recurrence and an excellent response after total thyroidectomy and radioiodine therapy.

MATERIALS AND METHODS

Medical records of patients who underwent serial follow-up neck US examinations between 1996 and 2022 were analyzed retrospectively. The utility of serial US examinations in detecting structural recurrence was assessed in all patients and different subgroups-categorized per the initial risk of recurrence and stimulated thyroglobulin (sTg) level at 1-year response assessment.

RESULTS

Among 2823 US examinations in 296 patients, 2 (0.1%) were categorized as true-positive, 2670 (94.6%) as true-negative, and 151 (5.3%) as false-positive, whereas no false-negative results were observed. Thus, sensitivity, specificity, positive predictive value (PPV), negative predictive value, and accuracy [confidence interval] in all patients were 100% [34.2-100%], 94.7% [93.8-95.4%], 1.3% [0.36-4.6%], 100% [99.9-100%], and 94.7% [93.8-95.4%], respectively. Non-significant higher PPVs were calculated in intermediate-risk patients and patients having sTg ≥0.1 ng/mL, while slightly lower specificity and accuracy were demonstrated in the former group. No recurrence was identified in patients with a low risk of recurrence and those having sTg <0.1 ng/mL.

CONCLUSION

Frequent US examination yields remarkably low PPVs in identifying recurrences in ATA low-intermediate-risk patients with DTC and attaining excellent response after total thyroidectomy and radioiodine ablation. Therefore, US surveillance protocol should be individualized per the initial risk of recurrence and Tg levels at response assessment.

Impact of periodic neck ultrasonography on locoregional disease control in surveillance after total thyroidectomy for patients with low- and intermediate-risk papillary thyroid carcinoma: a propensity score-matched study

This study aimed to evaluate the impact of periodic neck ultrasonography (US) on postoperative surveillance for locoregional disease control of patients with low- and intermediate-risk papillary thyroid carcinoma (PTC) who underwent total thyroidectomy. This retrospective cohort study included patients with PTC who underwent total thyroidectomy and central neck dissection at our institution between January, 2000 and December, 2016. The patients were divided into two groups: the physical examination (PE) group (follow-up by PE without periodic US) and the US group (follow-up by PE with periodic US). Serum thyroglobulin levels were measured periodically in both groups. Propensity score matching was used to rigorously balance the significant variables and assess the 10-year postoperative outcomes between the groups. Of the 189 patients, 150 were included after matching (75 in each group). There were no significant differences between the two groups in terms of background characteristics. The median follow-up period was 127.9 months. There was no significant difference in locoregional relapse-free survival between the PE and US groups (97.0 vs. 98.7%, p = 0.541). The overall survival was 96.7% and 98.7% in the PE and US groups, respectively, with no significant difference (p = 0.364). This study demonstrated that the addition of periodic US to PE for postoperative surveillance of patients with low- and intermediate-risk PTC who underwent total thyroidectomy did not significantly affect locoregional control.

Diagnostic Accuracy of Ultrasonography in Revision Thyroid Surgery: Can It Predict Disease Outcomes?

Revision thyroid surgery for residual/recurrent disease is known to have higher complication rates because of parathyroid injury and recurrent laryngeal nerve (RLN) damage. The aim of this study is to evaluate the accuracy of USG in predicting recurrent disease and disease outcomes in patients undergoing reoperation for recurrent/residual thyroid cancer. We performed a retrospective analysis of all thyroid reoperations from 2015 to 2017. Preoperative USG findings were categorized as per prespecified disease stations in the neck and compared with histopathology to calculate sensitivity, specificity, positive predictive value, and negative predictive value of USG. Survival analysis was performed using Kaplan-Meier curves. Two hundred fifty patients were included in the analysis. In a reoperative setting, USG had an overall sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of 89%, 77%, 89%, 94%, and 60%, respectively. We found a significantly lower disease-free survival in patients who had radiologically detected recurrent disease as compared to disease detected only on histopathology. USG has a reasonable accuracy in determining status of lesions in patients undergoing revision thyroid surgeries.

Constructing a nomogram based on the distribution of thyroid nodules and suspicious lateral cervical lymph nodes in fine-needle aspiration biopsies to predict metastasis in papillary thyroid carcinoma

Purpose

Elevated concentrations of thyroglobulin eluent is a risk factor for lateral cervical lymph node metastasis (LLNM) in patients with papillary thyroid cancer (PTC). We aimed to develop a practical nomogram based on the distribution of thyroid nodules and the presence of suspicious lateral cervical lymph nodes in fine-needle aspiration biopsies (LN-FNABs), including the cytopathology and the suspicious lateral cervical lymph node (LLN) thyroglobulin eluent (Tg), to predict the possibility of LLNM preoperatively in patients with PTC.

Methods

The clinical data of PTC patients who were admitted to the Third Affiliated Hospital of Soochow University from January 2022 to May 2023 to undergo fine-needle aspiration biopsy (FNAB) were included in this study. A total of 208 patients in 2022 served as the training set (70%), and 89 patients in 2023 served as the validation set (30%). The clinical characteristics and LN-FNAB results were collected to determine the risk factors of LLNM. A preoperative nomogram was developed for predicting LLNM based on the results of the univariate and multivariate analyses. Internal calibration, external calibration, and decision curve analysis (DCA) were performed for these models.

Results

The multivariate logistic regression analysis showed that the maximum thyroid nodule diameter (Odds Ratio (OR) 2.323, 95% CI 1.383 to 3.904; p = 0.001), Tg level (OR 1.007, 95% CI 1.005 to 1.009; p = 0.000), Tg divided by serum thyroglobulin, (Tg/sTg) [odds ratio (OR) 1.005, 95% CI 1.001 to 1.008; p = 0.009], and cytopathology (OR 9.738, 95% CI 3.678 to 25.783; p = 0.000) (all p <  0.05) had a significant impact on the LLNM of patients with suspicious LLNs. The nomogram showed a better predictive value in both the training cohort [area under the curve, (AUC) 0.937, 95% CI 0.895 to 0.966] and the validation cohort (AUC 0.957, 95% CI 0.892 to 0.989). The nomogram also showed excellent internal and external calibration in predicting LLNM. According to the DCA, the diagnostic performance of this model was dependent on the following variables: maximum thyroid nodule diameter, Tg level, Tg/sTg, and cytopathology.

Conclusion

Based on the aforementioned risk factors, we believe that it is necessary to establish a personalized LLNM model for patients with PTC. Using this practical nomogram, which combines clinical and Tg risk factors, surgeons could accurately predict the possibility of LLNM preoperatively. The nomogram will also help surgeons to establish personalized treatment plans before surgery.

Long-term follow-up ultrasonography surveillance in a large cohort of patients with papillary thyroid carcinoma

OBJECTIVE

This study aimed to investigate the predictive factors as well as the time and age course of recurrence/persistence in a large cohort of postoperative patients with papillary thyroid carcinoma (PTC) based on the long-term ultrasonography (US) follow-up data.

METHODS

Between January 2007 and December 2016, 3106 patients underwent surgery for PTC and at least two postoperative US follow-up examination over more than three years. Tumor recurrence/persistence was confirmed based on the follow-up US data and histopathological results. Univariate and multivariate analyses were performed to evaluate the predictive factors of tumor recurrence/persistence. Kaplan-Meier survival analysis was used to evaluate the recurrence-/persistence-free survival curve based on the US results.

RESULTS

A total of 321(10.3%) patients developed tumor recurrence/persistence during 54.3 months of mean follow-up (range 36-135 months), including 268(83.5%) cases of lymph node recurrence/persistence, 37 (11.5%) cases of non-lymph node recurrence/persistence, and 16(5%) cases of both types. Recurrence/persistence was observed using US examination at a mean interval of 23.6 ± 21.6 months (range 1-135 months) after surgery and peak incidence was observed 1-2 years after initial treatment. Younger (20-30 years old) and older (70-80 years old) patients had a higher proportion of tumor recurrence/persistence. Multifocality, advanced T and advanced N stages were independent risk factors of tumor recurrence/persistence.

CONCLUSION

Tumor recurrence/persistence of PTC usually occurs during the early postoperative period. For patients with multifocal cancer, advanced T and N stage, the US surveillance examination should be cautiously performed, especially in younger and older patients.

Can ultrasensitive thyroglobulin immunoassays avoid the need for ultrasound in thyroid cancer follow-up?

PURPOSE

Differentiated thyroid cancer (DTC) is the most common endocrine neoplasm, with a rising incidence and a long life expectancy. It has recently been suggested that patients with low- and intermediate-risk DTC with a good response to treatment at one year could be followed up using only highly sensitive immunoassays for thyroglobulin (Tg). The aim of this study was to examine the serum Tg levels in a series of DTC patients with histologically proven persistent or recurrent diseases.

METHODS

The study involved 50 consecutive patients being routinely followed up at our center, whose clinical, histological, and biochemical data were retrospectively collected.

RESULTS

The false-negative rate of ultrasensitive serum Tg assay was 14.3% (5/35) overall, and limited to anti-thyroglobulin autoantibodies (TgAb)-negative patients. Among them, only one patient had an excellent response to treatment at one-year follow-up and was diagnosed with a 4 mm recurrence, after more than seven years of periodic ultrasounds. The size of the neck lesion documented in the histological report was slightly larger in patients with detectable as opposed to negative Tg values (P < 0.05).

CONCLUSIONS

Serum highly sensitive Tg is undetectable in a proportion of patients with a proven persistent or recurrent DTC. The reasons behind this phenomenon are still unknown. However, in low/intermediate-risk patients cured at one-year follow-up, highly sensitive Tg without neck US seems an appropriate strategy for patients' management.

Predictive Value of FNA-Tg and TgAb in Cervical Lymph Node Metastasis of Papillary Thyroid Carcinoma

Objectives: To analyze whether thyroglobulin (Tg) and anti-Tg antibody (TgAb) detection in fine-needle aspiration (FNA) of cervical lymph node (LN; LN-FNA-Tg and LN-FNA-TgAb) can predict LN metastasis and obtain the best cutoff value. Methods: The patients admitted to our hospital from January 2020 to March 2021 were prospectively enrolled. The LNs were sampled by FNA. All patients underwent thyroid surgery and neck dissection. LN-FNA-Tg, LN-FNA-TgAb, and blood Tg and TgAb were measured. The receiver operating characteristic curve analysis was used to determine the best cutoff points for positive LN. Results: There were 29 participants in the LN metastasis group and 42 in the nonmetastasis group. Compared with the nonmetastasis group, the participants in the metastasis group had higher LN-FNA-Tg (median: 1897 vs 7.74 ng/mL, P < .001), higher LN-FNA-TgAb (median: 15.65 vs 8.21 IU/mL, P < .001), and higher serum Tg (median: 25.4 vs 18.81 ng/mL); there were no differences in serum TgAb (median: 26.6 vs 28.6 IU/mL, P = .477). The best accuracy (87.5%) was observed with LN-FNA-Tg of >227.1 ng/mL, resulting in an area under the curve of 0.927, 84.5% sensitivity, and 89.5% specificity. LN-FNA-TgAb >10.85 IS/mL had an accuracy of 79.6%, sensitivity 64.8%, and specificity 89.5%. Serum Tg and TgAb had the lowest accuracy, with 64.2% and 57.4%, respectively, sensitivity of 53.5% and 67.6%, and specificity of 71.4% and 50.5%. Similar results were observed in first-operation participants and postoperative participants. Conclusions: LN-FNA-Tg has high accuracy, sensitivity, and specificity for detecting cervical LN in patients with papillary thyroid cancer.

Imaging of Treated Thyroid and Parathyroid Disease

The thyroid and parathyroid glands are endocrine structures located in the visceral space of the infrahyoid neck. Imaging plays a critical role in the evaluation of patients with thyroid cancer, both in the pre and posttreatment setting. Disorders of thyroid function, that is, hyperthyroidism and hypothyroidism, are also fairly common, although imaging utilization is less frequent with these conditions. Parathyroid dysfunction results in disordered calcium metabolism. Imaging is frequently applied in the preoperative assessment of these patients undergoing parathyroidectomy; however, routine imaging in the postoperative setting is uncommon. Parathyroid carcinoma is rare; however, imaging may be used in the pre and posttreatment setting.

Imaging of Cervical Lymph Nodes in Thyroid Cancer: Ultrasound and Computed Tomography

Sonographic evaluation of cervical lymph nodes in patients with thyroid malignancy is important both for preoperative staging and for post-treatment surveillance, and contrast-enhanced computed tomography plays a complementary role. Knowledge of anatomy and surgical approaches, combined with an understanding of the various imaging features that distinguish malignant from benign lymph nodes, allows for accurate staging, thereby enabling complete surgical initial resection.

Localización intraoperatoria de las recurrencias en cáncer de tiroides mediante la inyección de azul de metileno guiada por ecografía

Introducción. La cirugía para extirpación de metástasis en un cuello previamente intervenido afronta un reto para lograr una resección exitosa. El presente estudio pretende demostrar la utilidad de la técnica de inyección de azul de metileno, guiada por ecografía, para la localización intraoperatoria de lesiones recurrentes en cáncer de tiroides, para facilitar su resección. Métodos. Se realizó un estudio observacional, descriptivo y retrospectivo, en pacientes reintervenidos por recurrencia de carcinoma diferenciado de tiroides, durante un periodo de dos años y medio. Se utilizó la inyección intratumoral de azul de metileno guiada por ecografía para su identificación intraoperatoria de recurrencia. Se hizo análisis de variables demográficas y clínicas. Resultados. Este estudio incluyó 10 procedimientos en 9 pacientes, 77,8 % mujeres, con una media de edad de 54 años. Todos tenían un nivel de tiroglobulina detectable y elevado antes de la intervención; posteriormente, el 89 % presentó un descenso y el 33 % una adecuada respuesta bioquímica. La técnica agregó 10 minutos al tiempo quirúrgico. En el 100 % se identificaron de manera intraoperatoria los ganglios marcados; el promedio de ganglios resecados fue de 12, de los cuales, 6 fueron positivos, todos con carcinoma papilar de tiroides. Esta técnica se consideró de gran utilidad y de bajo costo en todos los casos. Discusión. Esta técnica se muestra como una estrategia efectiva para la identificación intraoperatoria de las recurrencias locorregionales en carcinoma de tiroides, permitiendo una disección ganglionar exitosa, disminuyendo complicaciones, tiempo quirúrgico y, especialmente, costos frente a otras intervenciones

Can shear wave elastography determine remnant thyroid tissue in the early postoperative period in patients with differentiated thyroid carcinoma?

PURPOSE

This study aims to investigate the usability of ultrasonography (US) and shear wave elastography (SWE) in detecting remnant thyroid tissue (RTT) within the first three postoperative months in patients who underwent total thyroidectomy (TT) for differentiated thyroid cancer (DTC) and who were scheduled for radioiodine (RAI) ablation therapy.

METHODS

Sixty-nine patients who underwent a TT operation due to DTC were included in the study. The participant's thyroid surgical bed was first evaluated by thyroid scintigraphy and then by greyscale US and SWE to investigate RTT. The participants were divided into two groups, those with and those without RTT. SWE quantitative data were compared between the two groups. Receiver operating characteristic (ROC) curve analysis was performed to determine the best cut-off values for stiffness and velocity in distinguishing RTT.

RESULTS

A total of 149 regions were analysed in 69 participants (43 females, 26 males). The average time elapsed after the operation was 65.2 ± 24.1 days. RTT was determined by scintigraphy and US-SWE in 38 (55%) patients. The stiffness and velocity values were significantly higher in the group with RTT than in the group without RTT. To distinguish RTT from the thyroid bed, the best cut-off values for stiffness and velocity were 15.7 kPa and 2.12 m/s, respectively.

CONCLUSIONS

US with SWE can detect RTT in the early postoperative period in patients who have undergone TT due to DTC and who are scheduled for RAI treatment. The use of US and SWE will be particularly beneficial in patients with RTT but who have false-negative Tg levels and RTT that is not I-131 avid.

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.

Excellent diagnostic performance of FNA-Tg in detecting lymph nodes metastases from papillary thyroid cancer

Background: Thyroglobulin washout of fine needle aspiration (FNA-Tg) has proved to be useful in detecting lymph node metastases from papillary thyroid cancer; however, the influences of thyroid gland, Hashimoto thyroiditis, serum thyroglobulin (Tg) and anti-TG antibody on the diagnostic performance of FNA-Tg are controversial. Patients & methods: We retrospectively collected the FNA-Tg results of 176 preoperative or postoperative patients (356 lymph nodes) who finally were diagnosed with papillary thyroid cancer. The diagnostic abilities of FNA-Tg were evaluated and compared under different circumstances. Results: The diagnostic performance of FNA-Tg was uninfluenced irrespective of the status of thyroid gland or serum anti-TG antibody. However, high serum Tg was positively correlated with FNA-Tg (Exp(B) = 1.57; 95% CI: 1.209-2.309; p = 0.001). Conclusion: FNA-Tg was an excellent diagnostic tool, but it should be interpreted with caution only if serum Tg is higher than 10 ng/ml.

Ultrasonography surveillance in papillary thyroid carcinoma patients after total thyroidectomy according to dynamic risk stratification

PURPOSE

To investigate the role of neck US surveillance in patients with papillary thyroid carcinoma (PTC) after total thyroidectomy according to dynamic risk stratification (DRS) based on response to initial therapy.

METHODS

This retrospective study included 812 patients with PTC who underwent total thyroidectomy with prophylactic central neck dissection from January 2003 through February 2007. The relative risk of recurrence/persistence according to DRS was evaluated with the multivariable Cox regression proportional hazard model.

RESULTS

There were 132 men and 680 women. The mean age at surgery was 45.2 years. Postoperative US was used for DRS. According to DRS, 676 patients had excellent response, 78 indeterminate response, 40 biochemical incomplete response, and 18 structural incomplete response to initial therapy. Neck US was performed during follow-up and detected locoregional recurrences in 21 patients (2.6%): 12 with excellent response, 2 with biochemical incomplete response, and 7 with structural incomplete response according to DRS. Only 1 patient (0.1%) with excellent response had a locoregional recurrence that exceeded 8 mm in its shortest diameter, which is the size cut-off for diagnostic US fine-needle aspiration in suspicious lymph nodes. This patient did not develop biochemical abnormalities during follow-up.

CONCLUSIONS

Postoperative neck US surveillance after total thyroidectomy with prophylactic central neck dissection is not essential in PTC patients who show excellent response to initial therapy. Future studies are needed to verify the role of US surveillance in patients who receive variable degrees of treatments.

[Follow-up of differentiated thyroid cancer]

The management of differentiated thyroid carcinoma has shown considerable changes in recent years, moving away from a fixed therapy regimen towards individual treatment strategies. The aim of our work (literature research) is to present current developments in the follow-up of differentiated thyroid cancer.For the management of individual follow-up, an initial evaluation and, at later time points, the re-evaluation of the risk of recurrence is crucial. The performance of I-131-diagnostics after radioiodine therapy can provide essential information and can be seen as a survey of a new baseline situation, in order to be able to draw a comparison in case of a rising Thyreoglobulin (Tg).The measurement of Tg with a highly sensitive assays shows a high negative predictive value. Negative Tg measurements with these assays seem to indicate complete remission even with Tg antibodies being present. An increasing Tg value in follow-up implies further diagnostic work-up, primarily neck ultrasonography. Sonographically suspicious findings should be subjected to fine needle biopsy, whereby in addition to cytological processing, determination of Tg from the sample can be recommended. If the suspicious lesion cannot be displayed sonographically and Tg values keep rising, computed tomography (CT) and magnetic resonance imaging (MRI) of the neck region can provide further information. FDG-PET/CT has also shown an excellent performance in this setting.The previously fixed therapy regimen has been realigned towards an individual treatment management. Current studies and guidelines lead to a repetitive recurrence risk evaluation and the adjustment of the aftercare planning to the individual risks with appropriately selected examination methods and personalized intervals of assessment.

Thyroglobulin Measurement in Needle Aspiration for Detection of Recurrences and Neck Metastases in Patients with Differentiated Thyroid Carcinoma: Significance of Anti-Tg Antibodies

The worldwide incidence of differentiated thyroid cancer (DTC) has increased in recent decades, likely due to frequent use of cervical ultrasonography (US) and US-guided fine needle aspiration biopsy (FNA)., US is performed during follow-up after thyroidectomy, and US-guided FNA with cytology is used if suspicious cervical lymph nodes (LN) or thyroid bed masses are detected. Knowing that serum anti-Tg antibodies (sTgAb) affect the use of serum Tg (sTg) as a tumor marker, the aim of our study was to assess the usefulness of Tg determination in needle aspirates (FNA-Tg) in presence of sTgAb. This retrospective study included 149 patients with DTC and 159 aspirations of suspicious LN and thyroid bed masses. As expected, there was a negative correlation between sTg and sTgAb levels (p<0.05), while FNA-Tg levels had a positive correlation with FNA-TgAb levels (p<0.05). Furthermore, we found a positive correlation between sTg and FNA-Tg levels (p<0.05), but not between sTgAb and FNA-TgAb or sTgAb and FNA-Tg. In conclusion, these results show that FNA-Tg values were not affected by sTgAb and that FNA-Tg measurement were highly effective in detecting cervical DTC metastases. However, combined use with cytology is suggested for neck evaluation because cytology could reveal metastases from other tumor sites.

Clinical application of the ultrasound-guided fine needle aspiration for thyroglobulin measurement to diagnose lymph node metastasis from differentiated thyroid carcinoma-literature review

Papillary thyroid carcinoma (PTC) generally has a good prognosis, but disease recurs in 25% to 30% of PTC patients and significantly reduces the survival rate. Lymph node metastasis (LNM) is reported in 20% to 50% of PTC patients, mainly in the neck, and 20% originates from recurrence. LNM of papillary thyroid carcinoma are a plausible prognostic factor to determine disease recurrence. Currently, fine needle lymph node aspiration for cytology (LN-FN-cytology) is the best modality to diagnose LNM but is limited by diagnostic sensitivity and sample error. Fine needle lymph node aspiration for thyroglobulin measurement (LN-FNA-Tg) could offer a reliable and quantitative diagnostic method for LNM. The combination of LN-FNA-cytology and LN-FNA-Tg could achieve almost 100% diagnostic sensitivity and specificity for LNM. Both treatment guidelines of the American Thyroid Association and European Thyroid Association recommend LN-FNA-Tg to diagnose LNM after total thyroidectomy. Diagnostic accuracy of the LN-FNA-Tg depends on optimal equipment, scanning protocol, skill, and experience of operators. Normal saline is mainly used for aspiration needle wash-out and buffer solution. And radioimmunoassay or immunoradiometric assay are widely used for the LN-FNA-Tg measurement. So far, there is no consensus about the diagnostic threshold of LN-FNA-Tg for positive LNM, but high LN-FNA-Tg, especially higher than 10 ng/mL, strongly favors LNM.

SONOGRAPHIC FOLLOW-UP OF PATIENTS WITH DIFFERENTIATED THYROID CARCINOMA: A COMPARISON OF THE ULTRASOUND ELASTOGRAPHY, POWER DOPPLER ULTRASOUND, AND B-MODE ULTRASOUND FEATURES IN DETECTING MALIGNANT LYMPH NODES

Objective: The aim of this study was to assess and compare the diagnostic power of B-mode ultrasonography (US), power Doppler US (PD), and ultrasound elastography (USE) in detecting malignant lymph nodes (LNs) during follow-up of patients who were operated on for differentiated thyroid cancer (DTC). Methods: In this prospective study, a total of 103 cervical LNs having suspicious malignant features from 72 patients with DTC were examined using US, PD, and USE. USE scores were classified from 1 to 3 according to the presence of elasticity (1, soft; 2, intermediate; 3, hard). The strain ratios (SRs) of all LNs were calculated according to adjacent muscle tissue. Results: The most-sensitive ultrasonographic features were hilum loss and hypoechogenicity, with 94.4% and 80.6% sensitivity and 93.5% and 84.4% negative predictive value, respectively. The most-specific feature was the presence of cystic component, with 98.5% specificity and 85.7% positive predictive value. Presence of diffuse/chaotic or irregular vascularity in PD had 47.2% sensitivity and 83.6% specificity in predicting metastasis. In USE, the sensitivity and specificity of score 3 were 56.7% and 74.2%, respectively. The median SR of metastatic LNs was higher than that of benign LNs (median SR [min-max], 3.0 [0.16 and 29] vs. 1.89 [0.26 and 37.9]), but the difference was not significant (P = .07). Multivariate logistic regression analyses revealed 4.9-, 6.6-, and 10-fold increases in metastasis risk for short/long axis ratio ≥0.5, nodal vascularity, and score 3 USE, respectively (P<.05). Conclusion: While USE had higher sensitivity, PD had higher specificity in detecting malignant LNs, but none of these techniques was as sensitive and specific as gray-scale US features. Abbreviations: CI = confidence interval; DTC = differentiated thyroid cancer; LN = lymph node; LN-Tg = lymph node-thyroglobulin; NPV = negative predictive value; PD = power Doppler; PPV = positive predictive value; ROI = region of interest; SR = strain ratio; US = ultrasonography; USE = ultrasound elastography.

Surveillance for Differentiated Thyroid Cancer Recurrence

Serum thyroglobulin monitoring along with anatomic and functional imaging play key roles in the surveillance of patients with differentiated thyroid cancer after initial treatment. Among patients with a disease stage justifying thyroid remnant ablation or with suspected metastatic disease, radioiodine whole-body scans are essential in the months after surgery. For patients with low to moderate-risk cancers, ultrasonography of the neck (with measurement of serum thyroglobulin on thyroid hormone replacement) are the best initial diagnostic modalities, and are often the only tests required. In individuals suspected of having distant metastases, CT, MRI, and 18F-FDG PET can make important contributions in localizing residual disease and monitoring its progression and responses to therapy, provided they are used in the appropriate setting.

Cervical Lymph Node Fine-Needle Aspiration and Needle-Wash Thyroglobulin Reflex Test for Papillary Thyroid Carcinoma

Fine-needle aspiration (FNA) cytology coupled with needle-wash thyroglobulin (FNA-Tg) testing is recommended for cervical lymph node (LN) biopsies in patients with a history of papillary thyroid carcinoma (PTC). However, the procedure has not been standardized with the assay for FNA-Tg testing. A standard operating procedure (SOP) has been generated at our facility for cervical LN FNAs with Tg reflex testing on patients with a history of PTC. The procedure requires FNA cytology to be reviewed first, and all cases not positive for PTC are reflexed for FNA-Tg testing with the Beckman Access thyroglobulin assay. The thyroglobulin cutoff value is ≤ 1.0 ng/mL. From 2016 to 2017, 117 patients, including 71 women and 46 men, were identified as having a history of PTC. Patients' clinical characteristics were collected from medical records. A total of 143 LN biopsies were investigated for these patients. The results show that four out of 11 (36.4%) non-diagnostic LNs and five out of five (100%) atypical/suspicious LNs tested positive for FNA-Tg. Among these nine patients with positive thyroglobulin testing, LN metastases were proven histologically for all nine patients, and two patients were treated with LN ablation. Out of 68 LNs positive for PTC, three had FNA-Tg results. FNA-Tg testing was ordered for unknown reasons on two positive LNs (> 5000 ng/mL thyroglobulin) from one patient. The third LN was tested due to non-classic morphology, and the result was less than the cutoff value. Three patients with negative LN biopsies were tested to have elevated (> 1.0 ng/mL) thyroglobulin levels. One patient (FNA-Tg ng/mL) was proven to have multiple metastatic LNs through follow-up surgery. However, no positive LN was identified for the other two patients who had FNA-Tg level of 4.1 ng/mL and 37 ng/mL respectively. This is likely due to contamination, as these two patients had intact thyroids. In our practice, the FNA-Tg test is a very useful adjunct test to LN FNA specimens with a non-positive diagnosis in patients with a history of PTC. Furthermore, FNA-Tg testing increases diagnostic sensitivity among non-diagnostic and atypical/suspicious LNs. However, FNA-Tg testing should not substitute conventional cytology due to the following reasons: (1) false-negative thyroglobulin lab results; (2) PTC with loss of thyroglobulin expression; (3) LN metastasis from other origins; and (4) false-positive thyroglobulin testing due to blood contamination in patients who are not completely athyrotic.

Routine thyroglobulin, neck ultrasound and physical examination in the routine follow up of patients with differentiated thyroid cancer-Where is the evidence?

PURPOSE

Patients with differentiated thyroid cancer (DTC) typically have a favourable prognosis and recurrence as late as 45 years after diagnosis has been reported. International clinical guidelines for monitoring recommend routine thyroglobulin, ultrasound and physical examination for the detection of recurrence. The aim of this review was to systematically review whether routine monitoring using thyroglobulin (Tg), neck ultrasound and physical examination for recurrence in differentiated thyroid cancer patients is effective in improving patient survival and/or quality of life.

METHODS

Primary studies were retrieved via a comprehensive search of three electronic bibliographic databases (PubMed, Web of Science Core Collection and Cochrane Library) without time restriction. Eligible studies must have reported on disease-free patients with DTC subject to long-term routine surveillance. The primary and secondary outcomes of interest were overall survival (or other survival parameters) and quality of life, respectively.

RESULTS

Literature searches yielded 5529 citations, which were screened by two reviewers. 241 full texts were retrieved. No randomised controlled trials or two-arm cohort studies on the effectiveness of any of the three specified interventions were identified. However, three 'single-arm' studies reporting long-term follow-up outcomes in patients undergoing regular surveillance were identified and appraised.

CONCLUSIONS

This review highlights a lack of empirical evidence to support current use of routine surveillance in DTC. Although early detection is possible, routine surveillance may lead to unnecessary intervention.

Papillary Thyroid Carcinoma Recurrence: Low Yield of Neck Ultrasound With an Undetectable Serum Thyroglobulin Level

OBJECTIVES

To assess the yield of neck ultrasound (US) when serum thyroglobulin (Tg) is undetectable (<0.1 ng/mL) compared to elevated serum Tg in patients with differentiated papillary thyroid carcinoma (PTC) treated with thyroidectomy and radioactive iodine 131 (RAI) ablation.

METHODS

A retrospective chart review was conducted from 2010 through 2015 at an academic institution evaluating US results in patients with serum Tg levels obtained within 6 months of a neck US examination after thyroidectomy and RAI. The reference standard for recurrence was pathologic results from US-guided fine-needle aspiration (FNA) or follow-up for at least 1 year.

RESULTS

Among 76 patients with undetectable serum Tg levels, there were 19 examinations in 18 patients in which US raised the possibility of recurrence. None of these 18 patients had recurrence by FNA (n = 8) or clinical follow-up of at least 1 year (n = 10). Among 65 patients with elevated serum Tg levels, there were 24 examinations in 22 patients in which US raised the possibility of recurrence. Twelve patients underwent FNA, with 9 patients (34.6%) showing PTC; 7 patients had follow-up neck US examinations showing stability of findings; and 3 patients were lost to follow up. The yield of neck US was significantly lower when serum Tg was undetectable compared to when levels were elevated (P = .001).

CONCLUSIONS

Neck US did not identify recurrent PTC when the serum Tg level was undetectable in patients who underwent total thyroidectomy and RAI therapy. Eliminating neck US when serum TG levels are undetectable could decrease unnecessary imaging examinations without negatively affecting the ability to detect recurrent disease.

Utility of routine ultrasonography follow-up after total thyroidectomy in patients with papillary thyroid carcinoma: a single-center study

BACKGROUND

This study aimed to assess the appropriate number of sessions and interval of routine follow-up ultrasonography (US) in patients who underwent total thyroidectomy for papillary thyroid carcinoma (PTC).

METHODS

Between January 2008 and December 2009, 569 patients underwent total thyroidectomy for PTC. Of the 569 patients, 44 were excluded from the study because of no US follow-up data for the neck (n = 43) or owing to indeterminate tumor recurrence/persistence (n = 1). The follow-up US for all the patients was performed by a single radiologist. Based on the cytohistopathological results, tumor recurrence/persistence was determined.

RESULTS

In the 525 patients, the mean interval to the last follow-up US was 54.7 months, and the mean number of follow-up US sessions was 4.4. Of the 525 patients, 31 (5.9%) showed nodal (n = 30) and non-nodal (n = 1) tumor recurrence/persistence. Patient age and N stage were independently associated with tumor recurrence/persistence. Among patients showing tumor recurrence/persistence after total thyroidectomy, the time at first detection of suspicious US findings on follow-up US was ≤8 months in 2 patients, between 10 and 23 months in 21, and ≥ 25 months in 8. In a receiver operating characteristic curve analysis, the number of sessions and interval of the provided follow-up US were inappropriate for the detection of tumor recurrence/persistence.

CONCLUSIONS

For the detection of tumor recurrence/persistence after total thyroidectomy in PTC patients, routine US follow-up with a 1- or 2-year interval may be excessive.

Analysis of postoperative ultrasonography surveillance after total thyroidectomy in patients with papillary thyroid carcinoma: a multicenter study

Background In papillary thyroid carcinoma (PTC) patients, postoperative ultrasonography (US) surveillance is recommended at intervals of six or 12 months even though evidence is weak. Purpose To determine the optimal interval of postoperative US surveillance in patients after total thyroidectomy for the treatment of PTC using multicenter data. Material and Methods A total of 1400 patients from seven tertiary hospitals who underwent total thyroidectomy for treatment of PTC were included. Based on a retrospective review of clinical and pathologic results, multiple factors were analyzed according to recurrence/persistence or no recurrence/persistence. In recurrence/persistence group, the interval and number of follow-up US sessions in the initial detection of recurrence/persistence were investigated. Results Of the 1400 patients, 115 (8.2%) showed tumor recurrence/persistence on follow-up US. Of 115 recurrence/persistence cases, 89 (77.4%) were initially detected on US: nodal recurrence/persistence (n = 92), non-nodal recurrence/persistence (n = 22), and both (n = 1). Among the clinical and pathologic factors, only tumor size and N stage were significant predictors for recurrence/persistence. In the recurrence/persistence group, the mean interval and number of follow-up US sessions in the initial detection of recurrence/persistence was 22.3 ± 16.8 months and 2.2 ± 1.9, respectively. Approximately two-thirds of recurrence/persistence cases (76/115, 66.1%) were detected in follow-up US within two years after total thyroidectomy. Conclusion In PTC patients after total thyroidectomy, the optimal interval of the first US follow-up may be one to two years after thyroid surgery, and the appropriate number of postoperative US surveillance sessions within the first five years may be only one or two.

Appropriate Frequency and Interval of Neck Ultrasonography Surveillance during the First 10 Years after Total Thyroidectomy in Patients with Papillary Thyroid Carcinoma

BACKGROUND

No previous study has employed the frequency and interval of follow-up ultrasonography (US) during the first 10 years after total thyroidectomy in patients with papillary thyroid carcinoma (PTC). The aim of this study was to determine the appropriate frequency and interval of follow-up US during the first 10 years in patients who have undergone total thyroidectomy for PTC.

METHODS

Two hundred seventy-two patients underwent total thyroidectomy for PTC at our institution from January 2006 to December 2007. Nineteen patients were excluded because of lack of US follow-up data for the neck. Follow-up US was performed by one of two radiologists in all patients. Tumor recurrence/persistence was confirmed by histopathology.

RESULTS

The mean interval between surgery and the final follow-up US examination was 79.0 months, and the mean number of follow-up US sessions was 5.9 in the 253 evaluable patients. Eleven patients (4.3%) developed tumor recurrence/persistence, which was detected on follow-up US within 5 years after total thyroidectomy in all cases. T and N stages were independently associated with tumor recurrence/persistence. The interval between surgery and first suspicion of tumor recurrence/persistence on follow-up US was ≤12 months in six patients and 20, 35, 41, 53, and 60 months in the remaining five patients.

CONCLUSION

For detection of tumor recurrence/persistence after total thyroidectomy in patients with PTC, one or two sessions of follow-up US during the first 2 years, depending on T and N stages and one session of follow-up US in every second year during the following 8 years may be appropriate.

Thyroid Cancer: Ultrasound Imaging and Fine-Needle Aspiration Biopsy

Ultrasound is critical in detection, diagnosis, and management of thyroid nodules. Ultrasound detection of regional nodal metastatic disease is based on abnormal nodal morphology rather than size and is critical to initial surgical and long-term management of thyroid cancer. Fine-needle aspiration biopsy is the gold standard for malignancy diagnosis in thyroid cancer. Thyroglobulin assay of nodal aspirates improves accuracy in diagnosis of metastases. Reporting lexicons assign risk levels to thyroid nodules with the goal of improving and standardizing patient management. Surveillance ultrasound in papillary microcarcinomas is being evaluated and compared with surgical management.

Biochemical Testing in Thyroid Disorders

This article summarizes the main principles for the appropriate use of laboratory testing in the diagnosis and management of thyroid disorders, as well as controversies that have arisen in association with some of these biochemical tests. To place a test in perspective, its sensitivity and accuracy should be taken into account. Ordering the correct laboratory tests facilitates the early diagnosis of a thyroid disorder and allows for timely and appropriate treatment. This article focuses on a comprehensive update regarding thyroid-stimulating hormone, thyroxine/triiodothyronine, thyroid autoantibodies, thyroglobulin, and calcitonin. Clinical uses of these biochemical tests are outlined.

Efficacy and safety of percutaneous ultrasound guided radiofrequency ablation for treating cervical metastatic lymph nodes from papillary thyroid carcinoma

PURPOSE

The aim of this study was to assess the effectiveness and safety of ultrasound guided percutaneous radiofrequency ablation (RFA) of cervical metastatic lymph nodes (LNs) from papillary thyroid carcinoma.

METHODS

54 metastatic LNs confirmed by percutaneous biopsy in 33 patients with previous total thyroidectomy and radioiodine therapy were enrolled in this retrospective study. US and contrast-enhanced ultrasound (CEUS) examinations were performed before ablation. Follow-up consisted of conventional US, CEUS, thyroglobulin (Tg) level at 1, 3, 6, and 12 months and every 6 months thereafter. In 3 months after ablation, US-guided core needle biopsy (CNB) was performed in the center, at the edge of the ablation area to exclude recurrence.

RESULTS

Technical success was obtained in all 54 lymph nodes (100%) without immediate or later major complications occurred. With a mean follow-up of 21 ± 4 months (range 12-24 months), there were no evidence of recurrence at ablated sites. After RFA, 33 metastatic LNs completely disappeared (33/54, 61.1%) and 21 metastatic lymph nodes remained as small scarlike lesions (21/54, 38.9%) at the last follow-up visit. The mean volume reduction ratio (VRR) was 32.7 ± 8.6% (range 21.2-59.3%), 46.8 ± 9.7% (range 33.6-68.1%), 62.5 ± 12.1% (range 42.5-95.4%), 77.1 ± 10.6% (range 54.3-100.0%), 89.2 ± 8.3% (range 68.7-100.0%) and 94.9 ± 5.3% (range 78.2-100.0%) at 1, 3, 6, 12, 18 and 24 months after RFA respectively. Significant differences in the VRR were found between every two follow-up visits (P < 0.001). At the last follow-up visit, the mean serum Tg level decreased from 10.2 ± 5.1 ng/ml (range 0.8-16.2 ng/ml) to 1.1 ± 0.8 ng/ml (range 0.2-3.1 ng/ml) (P < 0.001).

CONCLUSIONS

Ultrasound guided percutaneous RFA for cervical metastatic LNs from papillary thyroid carcinoma is a feasible, effective and safe therapy. This procedure shows a nonsurgical therapeutic option that can eradicate the lesions with a very low complication rate.

Measurement of thyroglobulin, calcitonin, and PTH in FNA washout fluids

Different imaging tools, circulating endocrine markers, and fine-needle aspiration (FNA) cytology are of great importance in the diagnosis and follow-up of different thyroid and parathyroid diseases. Sometimes, however, they are conflicting or inconclusive: interestingly, measuring endocrine markers (i.e. thyroglobulin, calcitonin, parathyroid hormone) in fluids from FNA proved to be a very useful complementary diagnostic tool in such cases. The determination of endocrine markers in fluids other than serum/plasma has been developed in the last years. Although studies have reported overall satisfactory results, a good standardization of procedures has not yet been reached, and further efforts should be made in order to better define pre-analytical, analytical, and post-analytical aspects. Here we reviewed critically the literature on the measurement of FNA endocrine markers, focusing on laboratory issues, such as preparation of the sample, choice of solution, and technical features of determination of these markers. Indeed, information for use of FNA-Tg, FNA-CT, and FNA-PTH in clinical practice was also provided.

Surveillance Neck Sonography After Thyroidectomy for Papillary Thyroid Carcinoma: Pitfalls in the Diagnosis of Locally Recurrent and Metastatic Disease

A sonographic examination of the neck performed 6 to 12 months after thyroid surgery in patients with differentiated thyroid cancer is strongly recommended by the American Thyroid Association and considered mandatory by the European Thyroid Association for locoregional surveillance. The aim of this article is to review the normal anatomic changes expected after thyroid surgery and the pathologic mimics of thyroid carcinoma recurrence in post-thyroidectomy patients as they appear on neck sonography. We hope to offer some pearls to increase diagnostic confidence in this setting.

ANALYSIS OF POSTOPERATIVE ULTRASONOGRAPHY SURVEILLANCE AFTER HEMITHYROIDECTOMY IN PATIENTS WITH PAPILLARY THYROID MICROCARCINOMA: A MULTICENTER STUDY

OBJECTIVE

The optimal follow-up interval for postoperative ultrasonography (US) surveillance after hemithyroidectomy in patients with papillary thyroid microcarcinoma (PTMC) is unclear. The purpose of this study was to evaluate the prevalence of tumor recurrence/persistence and to investigate the appropriateness of postoperative US surveillance in PTMC patients who underwent hemithyroidectomy.

METHODS

Our institutional review board approved this retrospective study. From 2000 to 2011, 800 patients underwent hemithyroidectomy as treatment for PTMC, as well as at least one session of postoperative follow-up US, at four different institutions. The images and data of postoperative US surveillance were retrospectively investigated by experienced radiologists at each institution. Based on the follow-up US and histopathologic results, locoregional tumor recurrence/persistence was determined.

RESULTS

Of the 800 patients, 82.2% had T1a, 17.8% had T3, and none had T1b, T2, T4a, or T4b disease; 6.9% had unknown N stage, 80.1% had N0, 13% had N1a, and none had N1b, based on histopathology. There were also no cases of distant metastasis after hemithyroidectomy. Among the patients, 784 (98%) showed no tumor recurrence/persistence, and 16 (2%) showed locoregional tumor recurrence/persistence during the follow-up period. The patients differed in the number of sessions and the intervals of postoperative follow-up US. In the 16 patients with tumor recurrence/persistence, the mean interval of postoperative follow-up US since the first US detection of tumor recurrence/persistence was 42.9 ± 25.9 months. All recurrence/persistence cases were subcentimeter.

CONCLUSION

Postoperative US surveillance at 1-or 2-year intervals may be unnecessary because of the very low recurrence rate in PTMC.

ABBREVIATIONS

EMR = electronic medical record; PTMC = papillary thyroid microcarcinoma; TNM = tumor, node, metastasis; US = ultrasonography; US-FNA = ultrasonography-guided fine-needle aspiration.

Serum thyroglobulin or thyroglobulin in fine-needle aspiration washout of metastatic lymph nodes: which one should we have confidence in for the surveillance of thyroid carcinoma?

BACKGROUND

The objective of this study was to evaluate the diagnostic performance of serum thyroglobulin (S-Tg), thyroglobulin in fine-needle aspiration washout (FNA-Tg) and fine-needle aspiration cytology (FNAC) in the detection of lateral metastatic lymph nodes (LNs) in patients with thyroid carcinoma.

METHODS

The study included 19 lateral metastatic LNs from 19 patients with thyroid carcinoma who underwent FNAC for the suspicion of metastatic disease on ultrasonogrphy (US). The S-Tg, FNA-Tg, FNAC, and histopathological results were correlated.

RESULTS

Compared with S-Tg, both FNAC and FNA-Tg showed higher sensitivity (89.5%, 89.5% versus 68.4%, respectively) and accuracy (89.5%, 89.5% versus 68.4%, respectively). The combined use of FNAC and FNA-Tg or FNAC and S-Tg showed superior diagnostic power.

CONCLUSIONS

S-Tg measurement is a less reliable method for follow-up in patients with thyroid carcinoma in comparison with FNA-Tg. For patients with negative S-Tg but suspicious features in US, FNAC combined with FNA-Tg is strongly recommended to confirm the diagnosis.

Magnetic Probe–Guided Excision of Nonpalpable Neck Lesions

Background: Reoperative neck surgery is technically more demanding because of the presence of scar tissue and distorted anatomy. We aimed to investigate the magnetic probe–guided excision of nonpalpable neck lesions in patients with previously operated neck compartments. Methods: This study included 9 patients with recurrent/persistent thyroid carcinoma, recurrent/persistent hyperparathyroidism with previously operated neck compartments. The pathologic lesions were localized by ultrasonography, and magnetic tracer (0.2 mL, iron oxide) was injected directly into the pathologic lesions. Careful dissection was carried out following the area of maximum magnetic activity until the nonpalpable lesions were identified and excised. Result: All neck lesions were removed in 9 patients. The median count from lesion was significantly higher than values from lesion bed (background activity; (9900/5 seconds vs 250/5 seconds, P < .001). During follow-up, all patients had negative ultrasonography. Conclusion: Magnetic probe–guided technique could provide access to nonpalpable lesion localization in centers without readily available access to nuclear medicine facilities.

Lymph node fine-needle aspiration washout thyroglobulin in papillary thyroid cancer: Diagnostic value and the effect of thyroglobulin antibodies

PURPOSE

Thyroglobulin (Tg) assessment in the needle washout after fine-needle aspiration biopsy (FNAB) of a suspicious neck lymph node (LN) is known to improve the diagnostic accuracy in patients with papillary thyroid cancer (PTC). However, there is still controversy on the best diagnostic cut-off levels for FNAB-Tg and whether thyroglobulin antibody (TgAb) positivity affects FNAB-Tg. The objectives of this study were to determine (i) the diagnostic power of different cut-offs for FNAB-Tg and (ii) if serum TgAb(+) negatively affects the FNAB-Tg evaluation.

METHODS

This was a retrospective cohort study analyzing PTC patients with suspicious neck LNs, in a university hospital setting, from October 2009 to October 2013. In total, 103 patients with PTC (226 LNs) undergoing ultrasound-guided FNAB for LNs were included. Cytology and FNAB-Tg levels were compared in reference to LN histopathology and the effect of TgAb(+) on FNAB-Tg levels was evaluated.

RESULTS

The diagnostic accuracies of FNAB-Tg cut-off of 1 and 10 ng/mL were 94.1% and 88.2%, respectively. Raising the cut-off from 1 to 10 ng/mL led to decreased sensitivity rates (91.9% vs. 83.9%). The receiver operating characteristic curve analysis demonstrated that the best FNAB-Tg cut-off was 1.2 ng/mL. There were no LNs with an FNAB-Tg ≥ 10 ng/mL that turned out to be cytologically or histopathologically benign. FNAB-Tg levels of the histopathologically malignant LNs were similar between TgAb (+) and TgAb (-) patients (p = 0.546). Serum Tg predicted FNAB-Tg levels above 1 ng/mL (p = 0.002) and FNAB-Tg predicted malignant histopathology (p = 0.004), both independently of the TgAb status of the patient.

CONCLUSIONS

FNAB-Tg ≥ 1 ng/mL has a superior diagnostic power, irrespective of TgAb (+), in PTC patients with suspected LN involvement.

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.

Thyroglobulin Measurement in Fine-Needle Aspiration Improves the Diagnosis of Cervical Lymph Node Metastases in Papillary Thyroid Carcinoma

BACKGROUND

Papillary thyroid carcinoma (PTC) is frequently associated with cervical lymph node metastases. Guidelines recommend performing ultrasound-guided fine-needle aspiration cytology (FNAC) for suspicious nodes to guide management. No specific recommendations are available for the use of FNA thyroglobulin assay (FNA-Tg). This study investigated the diagnostic value of performing FNAC and FNA-Tg.

METHODS

Patient demographics, preoperative investigations, surgery, and lymph node pathology were collected for patients with PTC who underwent lateral neck lymphadenectomy and central compartment reexploration from January 2000 to July 2015. Sensitivities and accuracies were obtained. Patients with both diagnostic studies performed were compared using McNemar's test of paired proportion. Patient, imaging, and lymph node characteristics were correlated with test accuracy.

RESULTS

The 480 patients in this study underwent 706 lateral neck dissections or central compartment reexploration. All the patients underwent preoperative neck ultrasound. Among these patients, FNAC alone was performed before 426 operations (60 %), FNAC with FNA-Tg before 105 operations (15 %), and surgery without biopsy for 175 patients (25 %). The sensitivity, positive predictive value, and accuracy were respectively 96, 95, 100 % for FNAC, 99, 97, and 97 % for FNA-Tg, and 95, 92, and 97 % for FNAC in combination with FNA-Tg. In the subgroup of patients who had both tests performed, the sensitivity of FNA-Tg was superior to that of FNAC (95 vs 87 %; p = 0.04). The addition of FNA-Tg to FNAC increased the detection of metastatic PTC by 13 %.

CONCLUSIONS

For diagnosing cervical lymph node metastases in PTC, FNA-Tg is a valuable adjunct to FNAC. Its use should be considered to avoid missing metastatic disease in patients who may benefit from lymphadenectomy.

Recurrence Incidence in Differentiated Thyroid Cancers and the Importance of Diagnostic Iodine-131 Scintigraphy in Clinical Follow-up

Objective:

Differentiated thyroid cancers (DTC) are tumors with good prognosis. However, local recurrence or distant metastasis can be observed. In our study, we aimed to investigate the incidence of recurrence and the importance of diagnostic iodine-131 whole body scan (WBS) in clinical follow-up in patients with DTC.

Methods:

The clinical data of 217 patients with DTC who were followed-up more than 3 years were reviewed retrospectively. The incidence of recurrence was investigated in a group of patients who had radioactive iodine (RAI) treatment and showed no sign of residual thyroid tissue or metastasis with diagnostic WBS that was performed at 6-12 months after therapy and had a thyroglobulin (Tg) level lower than 2 ng/dl.

Results:

At the time of diagnosis, ten cases had thyroid capsule invasion, 25 cases had extra-thyroid soft tissue invasion, 11 patients showed lymph node metastasis and four patients had distant organ metastasis. One hundred forty-five patients had RAI treatment at ablation dose (75-100 mCi), whereas 35 patients had RAI treatment at metastasis dose (150-200 mCi). Thirty-seven patients with papillary microcarcinoma did not receive RAI treatment. In 12 (%7.5) of the 160 patients who were considered as “successful ablation”, a recurrence was identified. Recurrence was detected by diagnostic WBS in all cases and stimulated Tg level was <2 ng/dL with the exception of the two cases who had distant metastasis.

Conclusion:

Identification of pathological findings with WBS in patients who developed local recurrence in the absence of elevated Tg highlights the importance of diagnostic WBS in clinical follow-up.

Ultrasonographic differentiation of cervical lymph nodes in patients with papillary thyroid carcinoma after thyroidectomy and radioiodine ablation: a prospective study

OBJECTIVE

The objective of the present study was to validate an ultrasound (US) classification of cervical lymph nodes (LNs) in patients with papillary thyroid cancer (PTC) after thyroidectomy and radioactive iodine (131I) ablation.

METHODS

We performed a prospective study in which the patients were submitted to thyroidectomy and 131I ablation and then followed until neck US revealed LN(s) ≥5 mm. A total of 288 LNs from 112 patients with PTC were evaluated. Patient management was based on LN characteristics grouped according to the classification system studied here.

RESULTS

The presence of microcalcifications and/or cystic degeneration of cervical LNs were highly suggestive of a metastatic etiology (specificity of 99.4%). In contrast, the most sensitive finding for LNs affected by PTC was the absence of an echogenic hilum (sensitivity of 100%). In the absence of these findings (microcalcifications, cystic degeneration, echogenic hilum), a metastatic etiology was the most likely in the case of a round LN (specificity of 89%). The differentiation of a spindle-shaped LN without a visible hilum by Doppler analysis permitted us to dichotomize an initial probability of metastases of 13% in 25% (with peripheral vascularization) versus 3.3% (without peripheral vascularization).

CONCLUSIONS

Our results confirm that the classification proposed for cervical LNs in patients with PTC is valid for determining patient management following initial therapy.

Long-term follow-up ultrasonography after lobectomy in papillary thyroid microcarcinoma patients: A single-center study

PURPOSE

This study aimed to assess the prevalence of tumor recurrence and to determine the appropriate interval of follow-up ultrasonography (US) in papillary thyroid microcarcinoma (PTMC) patients who underwent lobectomy.

METHODS

Between January and December 2006, 137 patients underwent a lobectomy for the treatment of PTMC and at least one postoperative US follow-up examination. The postoperative follow-up US was performed by a single radiologist for all patients. Based on the follow-up US and histopathological results, tumor recurrence and nodal metastasis were determined.

RESULTS

In the 137 patients, the following diagnoses were made after lobectomy: intraglandular PTMC (n = 104), focally perithyroidal PTMC invasion within surgical margins (n = 18), nodal metastasis to the ipsilateral level VI node (n = 20), and satellite PTMC (n = 7). The patients showed differences in the number of post-operative follow-up US sessions and in the intervals of those sessions. Of the 137 patients, 135 (98.5%) exhibited no tumor recurrence on the follow-up US, whereas 2 (1.5%) exhibited tumor recurrence in the remnant thyroid gland. In these two patients with tumor recurrence, suspicious thyroid nodules were detected at the 96- and 90-month follow-up US, respectively.

CONCLUSIONS

In this study, the PTMC tumor recurrence rate was low, indicating that early post-lobectomy follow-up US in short intervals is not beneficial for detecting PTMC recurrence.

Thyroid Cancer in Pediatrics

Well differentiated thyroid cancer (DTC) in children is characterized by a high rate of response to treatment and low disease-specific mortality. Treatment of children with DTC has evolved toward a greater reliance on evaluation and monitoring with serial serum thyroglobulin measurements and ultrasound examinations. Radioiodine therapy is recommended for thyroid remnant ablation in high-risk patients, treatment of demonstrated radioiodine-avid local-regional disease not amenable to surgical resection, or distant radioiodine-avid metastatic disease. Sufficient time should be given for benefits of radioiodine therapy to be realized, with follow-up monitoring. Re-treatment with radioiodine can be deferred until progression of significant disease manifests.

2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer: The American Thyroid Association Guidelines Task Force on Thyroid Nodules and Differentiated Thyroid Cancer

BACKGROUND

Thyroid nodules are a common clinical problem, and differentiated thyroid cancer is becoming increasingly prevalent. Since the American Thyroid Association's (ATA's) guidelines for the management of these disorders were revised in 2009, significant scientific advances have occurred in the field. The aim of these guidelines is to inform clinicians, patients, researchers, and health policy makers on published evidence relating to the diagnosis and management of thyroid nodules and differentiated thyroid cancer.

METHODS

The specific clinical questions addressed in these guidelines were based on prior versions of the guidelines, stakeholder input, and input of task force members. Task force panel members were educated on knowledge synthesis methods, including electronic database searching, review and selection of relevant citations, and critical appraisal of selected studies. Published English language articles on adults were eligible for inclusion. The American College of Physicians Guideline Grading System was used for critical appraisal of evidence and grading strength of recommendations for therapeutic interventions. We developed a similarly formatted system to appraise the quality of such studies and resultant recommendations. The guideline panel had complete editorial independence from the ATA. Competing interests of guideline task force members were regularly updated, managed, and communicated to the ATA and task force members.

RESULTS

The revised guidelines for the management of thyroid nodules include recommendations regarding initial evaluation, clinical and ultrasound criteria for fine-needle aspiration biopsy, interpretation of fine-needle aspiration biopsy results, use of molecular markers, and management of benign thyroid nodules. Recommendations regarding the initial management of thyroid cancer include those relating to screening for thyroid cancer, staging and risk assessment, surgical management, radioiodine remnant ablation and therapy, and thyrotropin suppression therapy using levothyroxine. Recommendations related to long-term management of differentiated thyroid cancer include those related to surveillance for recurrent disease using imaging and serum thyroglobulin, thyroid hormone therapy, management of recurrent and metastatic disease, consideration for clinical trials and targeted therapy, as well as directions for future research.

CONCLUSIONS

We have developed evidence-based recommendations to inform clinical decision-making in the management of thyroid nodules and differentiated thyroid cancer. They represent, in our opinion, contemporary optimal care for patients with these disorders.

THERAPY OF ENDOCRINE DISEASE: Central neck dissection: a step forward in the treatment of papillary thyroid cancer

Since its introduction in the '70s and '80s, CND for papillary cancer is here to stay. Compartment VI should always be explored during surgery for papillary thyroid carcinoma (PTC) for obvious lymph node metastases. These can be easily spotted by an experienced surgeon or, eventually, by frozen section. No doubt, obvious nodal disease in the Delphian, paratracheal and subithsmic areas should be dissected in a comprehensive manner (therapeutic central neck dissection), avoiding the selective removal of suspicious nodes. Available evidence for routine prophylactic CND is not completely satisfactory. Our group's opinion, however, is that it reduces or even eliminates the need for repeat surgery in the central neck, better defines the extent (and stage) of the disease and provides a further argument against routine radioiodine ablation. Thus, PTC is becoming more and more a surgical disease that can be cured by optimized surgery alone in the majority of cases. Prophylactic CND, however, involves a higher risk for the parathyroid function and should be skilfully performed, preferably only on the same side as the primary tumour and preserving the cervical portion of the thymus.

Management Guidelines for Children with Thyroid Nodules and Differentiated Thyroid Cancer

BACKGROUND

Previous guidelines for the management of thyroid nodules and cancers were geared toward adults. Compared with thyroid neoplasms in adults, however, those in the pediatric population exhibit differences in pathophysiology, clinical presentation, and long-term outcomes. Furthermore, therapy that may be recommended for an adult may not be appropriate for a child who is at low risk for death but at higher risk for long-term harm from overly aggressive treatment. For these reasons, unique guidelines for children and adolescents with thyroid tumors are needed.

METHODS

A task force commissioned by the American Thyroid Association (ATA) developed a series of clinically relevant questions pertaining to the management of children with thyroid nodules and differentiated thyroid cancer (DTC). Using an extensive literature search, primarily focused on studies that included subjects ≤18 years of age, the task force identified and reviewed relevant articles through April 2014. Recommendations were made based upon scientific evidence and expert opinion and were graded using a modified schema from the United States Preventive Services Task Force.

RESULTS

These inaugural guidelines provide recommendations for the evaluation and management of thyroid nodules in children and adolescents, including the role and interpretation of ultrasound, fine-needle aspiration cytology, and the management of benign nodules. Recommendations for the evaluation, treatment, and follow-up of children and adolescents with DTC are outlined and include preoperative staging, surgical management, postoperative staging, the role of radioactive iodine therapy, and goals for thyrotropin suppression. Management algorithms are proposed and separate recommendations for papillary and follicular thyroid cancers are provided.

CONCLUSIONS

In response to our charge as an independent task force appointed by the ATA, we developed recommendations based on scientific evidence and expert opinion for the management of thyroid nodules and DTC in children and adolescents. In our opinion, these represent the current optimal care for children and adolescents with these conditions.