Stimulated Serum Thyroglobulin Levels Research Articles

Oncologic outcomes and surgical completeness of remote-access thyroidectomy: a systematic review and network meta-analysis.

The oncologic safety and surgical completeness of remote-access thyroidectomies are not yet clearly established. This study evaluates the oncologic outcomes and surgical completeness of three prevalent remote-access thyroidectomies: the gasless transaxillary approach (GTAA), bilateral axillo-breast approach (BABA), and transoral approach (TOA), in comparison with conventional transcervical thyroidectomy (CTT). Literature searches were conducted in PubMed, EMBASE, and the Cochrane Library databases, covering the period from 2000 to 2023. Network meta-analyses were performed on selected studies, focusing on recurrence and surgical completeness. Surgical completeness was assessed using stimulated serum thyroglobulin levels and the count of retrieved lymph nodes. The review included 48 studies, encompassing a total of 16,356 patients. The number of retrieved lymph nodes was comparable among BABA, TOA, and CTT, while GTAA might be less effective. Stimulated serum thyroglobulin levels showed no significant differences across the four groups. However, the proportion of patients with stimulated thyroglobulin levels below 1.0 ng/mL was significantly lower in GTAA compared to the other groups. The overall recurrence rates were 1.31% for CTT, 0.89% for GTAA, 0.62% for BABA, and 0% for TOA, with no significant differences in recurrence rates when adjusted for follow-up duration. This study demonstrated that the oncologic outcomes of GTAA, BABA, and TOA are comparable to those of CTT, based on recurrence rates. In terms of surgical completeness, BABA and TOA showed equivalence to CTT, whereas GTAA might be inferior to the other techniques.

TERT Promoter and BRAF V600E Mutations in Papillary Thyroid Cancer: A Single-Institution Experience in Korea.

Simple SummaryTERT promoter mutation has recently emerged as a promising prognostic biomarker for aggressive papillary thyroid cancer (PTC), along with BRAF B600E mutation. The prevalence of the TERT promoter mutations has been reported as relatively uncommon in Asian countries. We report on a prospective study of the TERT promoter and BRAF V600E mutation in the largest number of subjects with PTC in Korea. We assume that our specific clinical settings and the favorable healthcare environment in Korea led to several distinct findings: the lowest prevalence of TERT promoter mutation ever reported, multifocal gene mutations in bilateral PTCs, and more early-stage papillary microcarcinomas included in this study. This study indicates that relevant evaluation and treatment strategies should be investigated continuously based on different circumstances.Telomerase reverse transcriptase (TERT) promoter mutation has been investigated for its clinical and prognostic significance in aggressive papillary thyroid cancer (PTC). In this study, we aimed to assess the prevalence, clinicopathologic features, and treatment outcomes of TERT mutation-positive PTCs along with the common BRAF V600E mutation. We performed mutational analyses for BRAF and the TERT promoter in thyroid cancer patients who had undergone surgery at our institution since 2019. We reviewed and analyzed 7797 patients with PTC in this study. The prevalence of BRAF V600E and TERT promoter mutations was 84.0% and 1.1%, respectively. Multifocal gene mutations in bilateral PTCs were identified. TERT promoter mutations were associated with older age, larger tumor size, tumor multifocality, tumor variants, advanced stages, more adjuvant radioactive iodine treatment (RAI), higher stimulated serum thyroglobulin level before RAI, and more uptakes in the regions outside the surgical field on a post-RAI whole-body scan. The coexistence of BRAF V600E and TERT promoter mutations exacerbated all clinicopathologic characteristics. The frequency of TERT promoter mutations was the lowest in this study, compared to previous studies. TERT promoter mutations consistently correlated with aggressive PTCs, and the synergistic effect of both mutations was evident. Specific clinical settings in our institution and in Korea may have led to these distinctive results. Prospective multicenter studies with longer follow-up periods are required to establish valuable oncologic outcomes.

Treatment Response following Radioactive Iodine Therapy in Miliary versus Macronodular Pulmonary Metastases in Papillary Thyroid Carcinoma.

Background Pulmonary metastases in papillary thyroid carcinoma have two common presentations—micro/miliary (MM) and macronodular metastases (MN). The mainstay of treatment, posttotal thyroidectomy, is multiple radioactive iodine ablations (RAIA) every 6 to 12 months. Response assessment is determined by decline in stimulated serum thyroglobulin levels (sTg), disease regression on chest x-ray (CXR), computed tomography thorax, or whole body iodine scintigraphy (TWBS). Aim This study aims to assess the difference in response to RAIA based on the pattern of presentation. Methodology Retrospective analysis of patients from January 2008 to July 2017 was done. Patients with pulmonary metastases treated with RAIA (3700MBq per therapy as opposed to theAmerican Thyroid Association recommendation of 7400MBq per therapy) and a minimum follow-up of 8 months were included. The initial and the final sTg, TWBS, and CXR were analyzed for both groups. Final outcome in terms of complete response, disease regression, static disease, and disease progression was determined. Results Of the total of 1,793 patients, 71 were included. There were 43 females and 28 males. The median age was 39 years and the range was 14 to 79 years. Forty-five (63.3%) patients had MM and 26 (36.6%) patients had MN disease. The average number of therapies was three and maximum follow-up period was 15 years. Of the 45 MM patients, 1 had progression, 7 were static, 23 had regression, and 14 had complete response. Of the 26 MN patients, 22 had progression, 2 were static, 1 had regression, and 1 had complete response. Conclusion MM metastases, when compared with MN disease, respond to RAIA with a better outcome. In addition to achieving comparable response with a lower dose per therapy, there were no radiation-related long-term complications reported.

Impact of 18F-FDG PET/CT on treatment of patients with differentiated thyroid carcinoma, negative 131I whole body scan and elevated serum thyroglobulin.

Objective(s): 18F-FDG PET/CT is increasingly performed in patients with differen-tiated thyroid cancer. The aim of this study was to assess the clinical impact of 18F-FDG PET/CT on the management of patients with differentiated thyroid carcinoma who had elevated serum thyroglobulin (Tg) and negative 131I whole body scan (WBS). Methods:67 patients with differentiated thyroid carcinoma were included in this study. The findings of 18F-FDG PET/CT imaging were compared with histo-pathology, follow up imaging, or clinical follow-up results. The diagnostic accuracy of 18F-FDG PET/CT was evaluated for the entire patient group and for those patients with stimulated serum thyroglobulin levels of less than 5, 5–10, and more than 10 pmol/L as well as for local recurrences and metastases sites. The impact of 18F-FDG PET/CT on therapeutic management was also evaluated. Results:30/67 patients had positive findings on 18F-FDG PET/CT; 28 were true-positive and 2 were false-positive. 18F-FDG PET/CT results were true-negative in 36 patients and false-negative in 1 patient. The overall sensitivity, specificity, accuracy, PPV and NPV of 18F-FDG PET/CT were, 96.5%, 94.5%, 95.5%, 93.3%, and 97.2% respectively. Positive 18F-FDG PET/CT findings were directly correlated with stimulated serum thyroglobulin levels, 7.1% had Tg between 5–10, and 92.9% had Tg greater than 10 pmol/L. 18F-FDG PET/CT had a high or moderate impact on treatment management in 28 (41.8%) of patients.Conclusion: 18F-FDG PET/CT is able to improve diagnostic accuracy and have management impact in a therapeutically relevant way in patients with differentiated thyroid carcinoma who present with rising thyroglobulin level, negative 131I WBS, and clinical suspicion of recurrent disease.

OR21-07 The 2015 American Thyroid Association Risk Stratification System Is a Predictor of Persistent Disease in Real-World Clinical Practice

Background. Management and follow-up of differentiated thyroid cancer (DTC) are guided by the likelihood of disease persistence or recurrence. The American Thyroid Association (ATA) practice guidelines provide a risk-estimation system based on data mainly derived by retrospective, single-center, and small cohorts. Aim. To validate the ATA risk-stratification system in predicting persistent structural disease. Methods. We analyzed data from the Italian Thyroid Cancer Observatory’s observational, web-based database, which prospectively enrolls newly diagnosed DTC patients in 40 Italian centers. For the present study we selected consecutive cases satisfying the inclusion criteria: 1) histological diagnosis of DTC, including papillary, follicular, and poorly differentiated tumors; 2) registration in the ITCO database between January 1, 2013 and April 23, 2019; 3) clinical evaluation between 6 and 18 month after primary treatment, including enough data to estimate the response to the initial treatment. Exclusion criteria were: histological diagnosis of NIFTP, medullary, or anaplastic thyroid cancer. The response to the initial treatment was categorized as excellent, biochemical incomplete, structural incomplete, or indeterminate based on imaging findings (neck ultrasound and other imaging studies, if performed), basal or stimulated serum thyroglobulin levels, and anti-Tg antibody levels. To model the response to treatment, we used a cumulative link model; given the hierarchical structure of the data, with patients nested within centers, we used a mixed-effect model, with a center-specific intercept summarizing unobserved center-specific characteristics. Results. Complete data about initial treatment and response to treatment after 6-18 months since initial treatment was available for 2071 patients. According to the ATA system, 1109 patients (53.6%) were classified as low-risk, 796 (38.4%) as intermediate, and 166 (8.0%) as high-risk. Excellent response was recorded in 1576 (76.1%) patients, indeterminate in 376 (18.2%), biochemical incomplete in 33 (1.6%), and structural incomplete in 86 (4.2%).The ATA risk stratification system is a significant predictor of response to treatment after 6-18 months: classification as intermediate- and high-risk increased the likelihood of a response worse than excellent (OR 1.68 [95% confidence intervals, CI 1.34-2.10] and 3.23 [95% CI 2.23-4.67], respectively), and a persistent structural disease (OR 4.67 [95% CI 2.59-8.43] and 16.48 [95% CI 7.87-34.5], respectively. In both analyses, the effect of the center (taking into account center-specific features) was negligible and not statistically significant. Conclusion. The 2015 ATA risk stratification system is a reliable predictor of short-term outcomes in patients with DTC, also if applied in a real-world setting consisting of several different clinical sites.

Stimulated Serum Thyroglobulin Levels versus Unstimulated Serum Thyroglobulin in the Follow-up of Patients with Papillary Thyroid Carcinoma.

Serum thyroglobulin (Tg) and thyroid whole-body radioiodine scintigraphy (TWBS) are used in the follow-up of patients with papillary thyroid carcinoma (PTC) after total thyroidectomy. Symptoms of hypothyroidism are frequent as patients discontinue levothyroxine 1 month before visit, favoring the use of unstimulated serum Tg (uSTg) only. This study was done to determine the reliability of stimulated serum Tg levels (sSTg) over uSTg. A total of 650 patients with PTC came for follow-up between June 2011 and 2016. In those who had levels of uSTg and sSTg months measured within an interval of median of 3 months (range from 1 to 8 months), risk stratification was done as per the American Thyroid Association guidelines 2015. Intervention was based on a cutoff value of sSTg >10 ng/ml in our institution and the same was used for data analysis. Out of 650 patients, 106 had paired Tg values. Low-, intermediate-, and high-risk groups comprised 40, 31, and 35 patients, respectively. The sSTg >10 ng/ml with uSTg <10 ng/ml in the same patient was noted in 22.5% (9/40) of the low-risk, 41.9% (13/31) of the intermediate-risk, and 14.2% (5/35) of the high-risk groups. The levels were corroborated with tumor burden as determined by additional clinical, ultrasonography neck, and TWBS findings. Our study highlights the superiority of sSTg over uSTg in the follow-up of PTC patients. Follow-up with uSTg alone may result in underestimating the tumor burden.

Optimal threshold of stimulated serum thyroglobulin level for 18F-FDG PET/CT imaging in patients with thyroid cancer.

This study was to explore the optimal threshold of thyroid-stimulating hormone (TSH)-stimulated serum thyroglobulin (s-Tg) for patients who were to receive 18F-fluorodeoxyglucose (18F-FDG) PET/CT scan owing to clinical suspicion of differentiated thyroid cancer (DTC) recurrence but negative post-therapeutic 131I whole-body scan (131I-WBS). A total of 60 qualified patients underwent PET/CT scanning from October 2010 to July 2014. The receiver operating characteristic (ROC) curve analyses showed that s-Tg levels over 49 μg/L led to the highest diagnostic accuracy of PET/CT to detect recurrence, with a sensitivity of 89.5% and a specificity of 90.9%. Besides, bivariate correlation analysis showed positive correlation between s-Tg levels and the maximum standardized uptake values (SUVmax) of 18F-FDG in patients with positive PET/CT scanning, suggesting a significant influence of TSH both on Tg release and uptake of 18F-FDG. So, positive PET/CT imaging is expected when patients have negative 131I-WBS but s-Tg levels over 49 μg/L.

Higher preablative serum thyroid-stimulating hormone level predicts radioiodine ablation effectiveness in patients with differentiated thyroid carcinoma.

Radioiodine ablation of remnant thyroid tissue is an important adjuvant therapy of differentiated thyroid carcinoma (DTC) after thyroidectomy. Elevated serum thyroid-stimulating hormone (TSH) level is necessary for successful ablation. The optimum level of serum TSH level necessary for successful radioiodine ablation of well-DTC is, however, yet to be defined. We aimed to determine whether higher serum TSH level will result in a better rate of complete ablation of well-DTC using iodine-131 (I) following initial thyroidectomy. A total of 109 patients with differentiated thyroid cancer were divided into four treatment groups on the basis of serum TSH levels. They were followed up from 6 to 12 months after treatment with stimulated serum thyroglobulin level and a diagnostic whole-body scan with radioactive iodine I to determine early response. Sixty-four patients had papillary thyroid carcinoma, whereas 45 patients had follicular carcinoma. An excellent response was observed in 66.7% of patients with TSH level more than 90 μIU/ml, 72.2% in the group with TSH level of 60-89 μIU/ml, 48.5% when TSH was 30-59 μIU/ml and 26.7% when TSH was less than 30 μIU/ml (P=0.002). Higher preablative serum TSH predicts a better rate of ablation in patients with differentiated thyroid cancer treated with I after thyroidectomy.

Stimulated Serum Thyroglobulin Level at the Time of First Dose of Radioactive Iodine Therapy Is the Most Predictive Factor for Therapeutic Failure in Patients With Papillary Thyroid Carcinoma.

To investigate the clinical importance of serum thyroglobulin (Tg) levels just before high-dose I-131 ablation therapy (preablation Tg) for predicting therapeutic failure in patients with papillary thyroid carcinoma (PTC). Patients with PTC (n = 132) undergoing total thyroidectomy followed by the first high-dose I-131 ablation therapy (HI-Rx) were included in this retrospective review. Just before HI-Rx, preablation Tg, anti-Tg antibody, and TSH were measured. The patients were followed up for a mean period of 7months (range 6-23 months) by I-123 whole-body scans (f/u IWBS) and stimulated Tg (f/u Tg). Therapeutic failure was defined by positive f/u IWBS or f/u Tg >2ng/ml. We classified patients into three groups according to the value of preablation Tg (group 1, <1ng/ml; group 2, ≥1 and <10ng/ml; group 3, ≥10ng/ml) and compared clinical variables to therapeutic response. Therapeutic failure was noted in 39 patients (29.5%). On univariate analysis, T stage, tumor size, and preablation Tg were the statistically significant factors that could predict therapeutic failure. After multivariate analysis, preablation Tg was the only independent predictor of therapeutic failure (P < 0.001). The therapeutic failure rate was significantly increased as the preablation Tg level increased (11.3%, 33.3%, and 87.5% in groups 1, 2, and 3, respectively; P < 0.001). Individuals with preablation Tg levels ≥10ng/ml had 25.5 times greater chance of therapeutic failure than those with levels <10ng/ml (95% CI = 5.43-119.60; P < 0.001). A high preablation Tg level is the most significant predictor of therapeutic failure at the time of first HI-Rx in patients with PTC.

The Value of Postoperative Baseline Serum Thyroglobulin in Prediction of the Outcome of Radioactive Iodine-131 Thyroid Ablation in differentiated thyroid carcinoma

Background: Thyroglobulin is commonly used to monitor patients with differentiated cancer thyroid. It has also become an excellent biological marker for tumor persistence or recurrence. Aim ofstudy: To study the relation between the level of baseline serum thyroglobulin (TG) and thyroid remnant ablation outcome using radioactive iodine-131 (RAI-131) in patients with differentiated thyroid cancer after surgical treatment.Methods: A prospective study involved 64 patients (age 20-77 years) with differentiated thyroid cancer, referred for post-surgical 131I ablation. All patients performed baseline serum TG, anti-TGAb's under TSH stimulation as well as neck ultrasonography, before receiving RAI-131ablation dose 1110 - 3700 MBq (30 -100 mCi). Follow-up was performed 6-8 months later. Successful ablation was determined by negative whole body 131I scan, negative neck ultrasonography and stimulated serum thyroglobulin level less than 2 ng/mL. Results: Successful ablation was reported in 38 out of 64 cases (59.4 %). Baseline serum thyroglobulin level was significantly predictive of ablation outcome. ROC analysis showed AUC (area under curve) of 0.66 (CI: 0.53 - 0.78; P = 0.03). A cutoff value of 4.4 ng/ml showed sensitivity of 79 % and specificity of 68% in predicting ablation outcome. Patients were divided into high (n = 32) and low (n = 32) baseline TG groups using this cut-off point. Successful ablation significantly higher in low TG group (25/32 vs. 13/32; P=0.002). There was no significant difference between the two groups regarding their clinical and pathological data. Conclusion: Baseline serum thyroglobulin is associated with ablation outcome. Serum TG> 4.4 is linked to significantly higher rates of unsuccessful ablation.

Low but measurable stimulated serum thyroglobulin levels

Introduction: The study was aimed to determine the response and predictive risk factors of differentiated thyroid cancer (DTC) with measurable (0.4–2.0 µg/L) stimulated serum thyroglobulin (sTg) during the 10–24 months after radioiodine remnant ablation (RRA) and their long-term outcomes. Methods: Out of 839 retrospectively reviewed patients, 95 eligible DTC patients were included. Patients were classified as having incomplete response or no evidence of disease (NED). The sTg cut-off values with highest predicted accuracy for incomplete response at 10–24 months were calculated with receiver operator characteristics curve analysis. Results and Conclusion: At 10–24 months after RRA, incomplete response was identified in 54 patients (57%) and 38/54 (70.4%) patients were found with structural evidence of disease. The remaining 16 patients (29.6%) had biochemical evidence of disease without structural evidence of disease. Forty-one patients (43%) were classified as having NED at 10–24 months after RRA and 27 patients (66%) did not receive further radioactive iodine (RAI) therapy and remained disease free at median follow-up of 6.5 years. Fourteen patients received second RAI treatment after 6 months and before the 10–24 months assessment time point. Of these, 2 had persistent tumor 6 years later. The sTg >0.6 µg/L at 6–10 months after RRA had optimal sensitivity (83.3%), specificity (56%) and negative predictive value (72%) of detecting incomplete response at 10–24 months after RRA. A total of 23/43 patients in the American Thyroid Association low-risk category had incomplete response after first RRA and 5/23 (21.7%) had recurrent/persistent disease at long-term follow-up.

Recombinant Human Thyroid-Stimulating Hormone To Stimulate 131-1 Uptake For Remnant Ablation And Adjuvant Therapy

To review the current literature with regard to the use of recombinant human thyroid stimulating hormone (rhTSH) as an adjunct to radioactive iodine (RAI) remnant ablation and adjuvant therapy. Literature review of clinical studies examining rhTSH and/or thyroid hormone withdrawal preparations for RAI remnant ablation. The primary endpoints evaluated were (1) effectiveness at ablating the thyroid bed as demonstrated by the lack of significant uptake in the thyroid bed on follow-up diagnostic imaging and (2) effectiveness in facilitating the adjuvant therapy function of RAI ablation as manifested by follow-up thyroid stimulating hormone (TSH)-stimulated serum thyroglobulin levels and clinical outcomes (recurrence rates, likelihood of having no evidence of disease at final follow-up). RAI remnant ablation can be successfully achieved using either traditional thyroid hormone withdrawal or recombinant human TSH preparation. While initial studies included primarily thyroid cancer patients at low risk of recurrence, more recent studies suggest that rhTSH can also be effectively used as preparation for RAI ablation in patients with an intermediate or high risk of recurrence. Furthermore, while early studies focused primarily on the endpoint of thyroid bed remnant ablation, more recent retrospective studies suggest that final clinical outcomes (recurrence rates, likelihood of achieving no evidence of disease status at final follow-up) over 5-10 years of follow-up are very similar with either method of preparation. rhTSH is an effective alternative to thyroid hormone withdrawal in preparation for RAI remnant ablation in patients without evidence of distant metastases who are at low, intermediate, or high risk of recurrence.

Lung nodule detected by F-18 fluorodeoxyglucose positron emission tomography-computed tomography in patients with papillary thyroid cancer, negative 131I whole body scan, and undetectable serum-stimulated thyroglobulin levels: two case reports

IntroductionWhen a pulmonary nodular lesion is detected by F-18 fluorodeoxyglucose positron emission tomography-computed tomography in a patient with post-surgical papillary thyroid carcinoma with undetectable serum-stimulated thyroglobulin levels and negative 131I whole body scan, diagnosis and management of the nodule may be confusing.Case presentationWe describe two post-surgical patients with papillary thyroid carcinoma who showed pulmonary nodular lesions detected by F-18 fluorodeoxyglucose positron emission tomography-computed tomography. In both cases serum-stimulated thyroglobulin levels were undetectable and nodular lesions were not detected by 131I whole body scan. In the first case, a 64-year-old Asian woman showed one focal increased fluorodeoxyglucose uptake lesion in the right lower lobe of one of her lungs. Based on the histologic study, the pulmonary nodular lesion was diagnosed as a solitary pulmonary metastasis from papillary thyroid carcinoma. In the second case, a 59-year-old Asian woman showed a new pulmonary nodule in the right lower lobe. The computed tomography scan of her chest revealed a 9mm nodule in the anterior basal segment and another tiny nodule in the posterior basal segment of the right lower lobe. Six months later, both nodules had increased in size and miliary disseminated nodules were also seen in both lungs. Based on their histology, the pulmonary nodular lesions were considered to be primary lung adenocarcinoma.ConclusionsThe present cases emphasize that physicians should be cautious and make efforts for an accurate diagnosis of pulmonary nodules detected on F-18 fluorodeoxyglucose positron emission tomography-computed tomography in patients with papillary thyroid carcinoma with no evidence of metastasis such as negative 131I whole body scan and undetectable stimulated serum thyroglobulin levels.

The success rate of initial (131)i ablation in differentiated thyroid cancer: comparison between less strict and very strict low iodine diets.

To decrease the risk of recurrence or metastasis in differentiated thyroid cancer (DTC), selected patients receive radioactive iodine ablation of remnant thyroid tissue or tumor. A low iodine diet can enhance uptake of radioactive iodine. We compared the success rates of radioactive iodine ablation therapy in patients who followed two different low iodine diets (LIDs). The success rates of postsurgical radioactive iodine ablation in DTC patients receiving empiric doses of 150mCi were retrospectively reviewed. First-time radioactive iodine ablation therapy was done in 71 patients following less strict LID and 90 patients following very strict LID. Less strict LID restricted seafood, iodized salt, egg yolk, dairy products, processed meat, instant prepared meals, and multi-vitamins. Very strict LID additionally restricted rice, freshwater fish, spinach, and soybean products. Radioactive iodine ablation therapy was considered successful when follow-up (123)I whole body scan was negative and stimulated serum thyroglobulin level was less than 2.0ng/mL. The success rate of patients following less strict LID was 80.3% and for very strict LID 75.6%. There was no statistically significant difference in the success rates between the two LID groups (p = 0.48). Very strict LID may not contribute to improving the success rate of initial radioactive iodine ablation therapy at the cost of great inconvenience to the patient.

Postablation 131I scintigraphy with neck and thorax SPECT–CT and stimulated serum thyroglobulin level predict the outcome of patients with differentiated thyroid cancer

Neck and thorax single photon emission computed tomography with computed tomography (SPECT-CT) improves the reliability of postablation (131)I whole-body scan (WBS) for differentiated thyroid cancer (DTC). The aim of this study was to assess the prognostic value for persistent or recurrent disease of postablation (131)I scintigraphy combining WBS and neck and thorax SPECT-CT with that of the previously known predictive factors. This is a single referral center prospective study with a median follow-up of 29 months. Postablation (131)I WBS and neck and thorax SPECT-CT were performed in 170 consecutive patients treated between 2006 and 2008. Stimulated serum thyroglobulin (Tg) and anti-thyroglobulin antibodies (TgAb) levels were measured. The impact on disease-free survival of age; gender; postablation (131)I scintigraphy; stimulated serum Tg level; T, N, and M status; and macroscopic lymph node involvement was assessed by univariate and multivariate analyses. Persistent or recurrent disease was observed in 32 (19%) patients. In the whole group of patients, only positive WBS with SPECT-CT was related to an increased risk of persistent or recurrent disease (hazards ratio (HR)=65.21, 95% confidence interval (CI)=26.03-163.39, P<0.0001). In patients without TgAb (n=146), both positive WBS with SPECT-CT (HR=18.86, 95% CI=5.02-70.85, P<0.0001) and serum Tg level ≥58 ng/ml (HR=4.42, 95% CI=1.18-16.53, P=0.0271) were associated with an increased risk. In patients with DTC, the cross analysis of postablation (131)I scintigraphy with neck and thorax SPECT-CT and stimulated serum Tg level enables early assessment of the risk of persistent or recurrent disease.

Influence of prophylactic central lymph node dissection on postoperative thyroglobulin levels and radioiodine treatment in papillary thyroid cancer

Prophylactic central lymph node dissection with total thyroidectomy (TT) for the treatment of papillary thyroid cancer (PTC) is controversial because of the possibility of increased morbidity with uncertain benefit. The purpose of this study is to determine whether prophylactic central neck dissection provides any advantages over TT alone. Retrospective cohort study of patients with PTC without preoperative evidence of lymph node involvement undergoing either TT or TT with bilateral central lymph node dissection (TT + BCLND). From 2002 to 2009, 143 patients with clinically node-negative PTC underwent either TT (n = 65) or TT + BCLND (n = 78). The groups were similar in age, gender, tumor size, multifocality, angioinvasion, and metastasis/age/completeness-of-resection/invasion/size score. The presence of involved central neck lymph nodes upstaged 28.6% of patients in the TT + BCLND group to stage III disease, which resulted in higher radioactive iodine ablation doses. Stimulated serum thyroglobulin levels and the number of patients with undetectable stimulated thyroglobulin levels before and 1 year after radioactive iodine ablation were equivalent. The addition of routine central lymph node dissection to TT for the treatment of PTC upstages nearly one third of patients over the age of 45 thereby changing the dose of radioactive iodine ablative therapy, but does not change postoperative thyroglobulin levels after completion of radioiodine treatment.

Value of stimulated serum thyroglobulin levels for detecting persistent or recurrent differentiated thyroid cancer in high- and low-risk patients

Background: Serum thyroglobulin determination has been reported to be a sensitive indicator of persistent or recurrent differentiated thyroid cancer of follicular cell origin (DTC) after total thyroidectomy. The purpose of this investigation was to determine the accuracy of serum thyroglobulin levels in predicting persistent or recurrent DTC in euthyroid and hypothyroid patients. Methods: One hundred ninety consecutive patients with DTC of follicular cell origin who had 4 or more thyroglobulin levels measured after total thyroidectomy were retrospectively evaluated. One hundred fifteen patients had serum thyroglobulin levels measured when hypothyroid for radioiodine scanning or ablation. Serum thyroglobulin levels were determined by commercial assays. One hundred twenty-two patients less than 45 years old were considered at low risk, whereas 68 patients more than or equal to 45 years old were considered at high risk on the basis of TNM classification. The mean follow-up period was 62 months. Results: After thyroidectomy with or without central or modified radical neck dissection 120 patients had normal thyroglobulin levels (≤3 ng/mL) while receiving thyroid hormone. One hundred thirteen of the 120 patients (94%) with normal serum thyroglobulin levels had no evidence of recurrent tumor, whereas 6% (7 patients) had persistent or recurrent disease. Among 76 patients with persistent (28 patients) or recurrent (48 patients) disease, 70 had a serum thyroglobulin level >3 ng/mL while receiving thyroid hormone. Overall, 14 of 115 patients, including 2 of 61 (3%) in the high-risk group and 12 of 54 (22%) in the low-risk group, only had elevated serum thyroglobulin levels when hypothyroid with high serum thyroid-stimulating hormone (TSH) levels documenting persistent or recurrent disease. In 1 patient the serum thyroglobullin level (240 ng/mL) was falsely elevated probably as a result of interfering antibodies because no tumor was identified surgically or pathologically, and the thyroglobulin concentration was <3 ng/mL when analyzed in 3 other laboratories. Conclusion: Serum thyroglobulin testing is sensitive (91%) and specific (99%) for identifying patients with persistent or recurrent differentiated thyroid cancer. Serum thyroglobulin levels are most precise when patients are hypothyroid (high TSH) and may be unreliable in patients with antithyroglobulin antibodies. We recommend TSH-stimulated thyroglobulin testing for all patients after total thyroidectomy for differentiated thyroid cancer of follicular cell origin regardless of patient age or risk group. (Surgery 1999;126:13-9.)