Approach and safety of comprehensive central compartment dissection in patients with recurrent papillary thyroid carcinoma

Clinical outcomes of combined cervical and transthoracic surgical approaches in patients with advanced thyroid cancer

BACKGROUND

Advanced thyroid disease involving the mediastinum may be managed surgically with a combined transcervical and transthoracic approach. Contemporary analysis of this infrequently encountered cohort will aid the multidisciplinary team in personalizing treatment approaches.

METHODS

Retrospective review of patients undergoing combined transcervical and transthoracic surgery for thyroid cancer at a single high-volume institution from 1994 to 2015.

RESULTS

Thirty-eight patients with median age 59 years (range 28-76) underwent surgery without perioperative mortality. Most patients had primary disease. A majority had distant metastases outside the mediastinum but had locoregionally curable disease. Common complications were temporary (39%) and permanent (18%) hypoparathyroidism, and wound infection (13%). One-year overall survival was 84%; 1-year locoregional disease-free survival was 64%. Median time to locoregional recurrence was 36 months. Only esophageal invasion was associated with worse oncologic outcomes.

CONCLUSIONS

Combined transcervical and transthoracic surgery for advanced thyroid cancer can be performed without mortality and with acceptable morbidity.

Application of carbon nanoparticles combined with intraoperative neuromonitoring in papillary thyroid microcarcinoma surgery

PURPOSES

To improve the lymph node dissection as well as protect parathyroid gland and recurrent laryngeal nerve, the carbon nanoparticles and intraoperative neuromonitoring were applied in papillary thyroid microcarcinoma surgery.

METHODS

Carbon nanoparticles and intraoperative neuromonitoring were used in the experimental group, whereas the control group were not. Routine pathological examination was performed.

RESULTS

The lymph nodes dissected was significantly higher in the experimental group, but the metastatic lymph nodes were not. The number of mistakenly dissected parathyroid gland and postoperative hypoparathyroidism were 3 and 13 in the experimental group respectively, significantly less than 10 and 25 in the control group. The incidences of overall, transient and persistent recurrent laryngeal nerve palsy in the experimental group were 5.5%, 5.5% and 0% respectively, whereas in the control group were 8.6%, 6.9% and 1.7%.

CONCLUSIONS

Carbon nanoparticles can improve lymph node dissection in papillary thyroid microcarcinoma surgery, and the combination of carbon nanoparticles with intraoperative neuromonitoring can reduce surgical complications and improve patient quality of life.

Is There a Correlation of TSI Levels and Incidental Papillary Thyroid Carcinoma in Graves Disease? A Review of the Latest Evidence

PURPOSE

Our aim is to clarify if there is an association between the TSI levels and the development of thyroid carcinoma in patients with Grave's disease.

METHODS

A systematic search concerning original studies from 2010 to 2020 was carried out through the databases PubMed, EMBASE and Cochrane, according to the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) guidelines. The terms used are 'Graves' disease' and /or 'Incidental Papillary thyroid cancer' and 'TSI' levels. Retrospective studies upon the subject were concluded in the analysis.

RESULTS

Only three retrospective studies were found involving 916 patients with Graves' disease and Euthyroid goiter. No significant correlation has been found between TSI and the occurrence of thyroid carcinoma in patients with Graves' disease.

CONCLUSION

Very little research has been conducted upon the subject. More assays are required in order to identify a possible prognostic role of TSI levels in Papillary thyroid carcinoma in patients with Graves disease.

Pediatric Thyroid Cancer: Genetics, Therapeutics and Outcome

An increasing number of children are diagnosed with thyroid cancer. Most patients do not have an identifiable cause; however, tumor predisposition syndromes may be associated with development of both differentiated and medullary thyroid cancer. With an excellent prognosis for most patients, the goal of therapy is to optimize outcome and reduce complications. The increased knowledge of the oncogenic drivers provides opportunities to improve the accuracy of diagnosis, stratify surgery, and select systemic therapy that may be considered for neoadjuvant and adjuvant treatment. Treatment complications can be reduced by referral to regional, high-volume pediatric thyroid centers.

Papillary and Follicular Thyroid Cancer in children and adolescents: Current approach and future directions

An increasing number of children are diagnosed with differentiated thyroid cancer. With an excellent prognosis for the majority of pediatric patients, the goal of therapy is to optimize outcome while reducing complications. Increased knowledge of the somatic, oncogenic driver mutations provides opportunities to improve the accuracy of diagnosis, to stratify surgery, and to treat patients with morbidly invasive or refractory disease. Treatment complications can be reduced by referral to regional, high-volume pediatric thyroid centers.

Central compartment revision surgery for persistent or recurrent thyroid carcinoma: analysis of survival and complication rate

PURPOSE

Locoregional recurrence of thyroid carcinoma is relatively common and reported rate are between 5 and 20%. Cervical nodes are usually involved, especially at the central compartment. The management of recurrent thyroid carcinoma at central compartment still remains challenging because of higher incidence of complication rate. The aim of the study is to evaluate the survival and complications rate after revision surgery.

METHODS

Retrospective cohort study on a group of patients that underwent revision surgery for persistent or recurrent thyroid carcinoma from January 1, 2003 to December 31, 2017. Survival outcomes were calculated using Kaplan-Meier method. Significant variables on univariate analysis were subjected to a Cox proportional hazards regression multivariate model.

RESULTS

Fifty-two patients involved, 22 male (40%) and 30 female (60%). Mean age was 54 years old (range 24-85). Mean follow-up was 79 months, median follow-up was 85 months, with a range between 8 and 153 months. The 5-year overall survival was 90.8% while at 10 years it was 69.8%. The 5-year disease-specific survival was 93.5%, while at 10 years it dropped to 77.9%. The rate of recurrent laryngeal nerve paralysis and persistent hypocalcemia in our series were 1.3% and 5.9%, respectively. No evidence of thoracic duct, esophageal or laryngeal and tracheal injury was found in this case series. Regarding prognostic factors, univariate and multivariate analysis highlighted as statistically significant: the aggressive histological variants, the presence extranodal extension or soft-tissue metastasis.

CONCLUSION

The surgical option remains the gold standard in locoregional recurrences of thyroid carcinoma and should be performed by experienced surgeons to reduce postoperative complications.

Persistent/Recurrent Differentiated Thyroid Cancer: Clinical and Radiological Characteristics of Persistent Disease and Clinical Recurrence Based on Computed Tomography Analysis

BACKGROUND

The natural course of persistent/recurrent differentiated thyroid cancer (DTC) has not been fully elucidated. The purpose of this study was to assess the relative incidence and clinico-radiological characteristics of persistent disease and clinical recurrence based on computed tomography (CT) analysis in patients with persistent/recurrent DTC.

METHODS

From January 2005 to December 2016, this retrospective study included 107 patients (M:F = 28:79; M_age = 53.5 years) with surgically proven cervical locoregional recurrence of DTC. Two neck CT examinations (median interval 1.92 years; range 0.17-7.58 years) before the last thyroid cancer surgery within the study period were reevaluated. Based on the presence of the lesion on the first CT and its progression on the second CT, the locoregional recurrence was classified into the following categories: stable persistence (decrease, no change, or increase by <2 mm in short dimension on the second CT), progressive persistence (increase by ≥2 mm), and clinical recurrence (newly appeared on the second CT). Clinical and radiological characteristics of the three groups were compared using univariate and multivariate logistic regression analyses.

RESULTS

The relative incidences of stable persistence, progressive persistence, and clinical recurrence were 56.1% (60/107), 15.0% (16/107), and 29.0% (31/107), respectively. Multivariate analysis between the clinical recurrence (29.0%) and persistence (71.0%) groups revealed various independent factors for prediction of clinical recurrence. These included longer interval between the two CT examinations (median 2.67 vs. 1.79 years; p = 0.021), a smaller number of thyroid surgeries (1.16 ± 0.45 vs. 1.55 ± 0.81; p = 0.002), and a history of neck dissection at the location of the largest locoregional recurrence (70.0% vs. 31.4%; p < 0.001). There was no significant independent factor for differentiation between the stable persistence (78.9%; 60/76) and progressive persistence (21.1%; 16/76) groups. The results may have been influenced by selection bias because this study included only surgically proven cases.

CONCLUSIONS

With regard to cervical locoregional recurrence of DTC, active surveillance may be favored because more than a half of the cases are structurally persistent and stable. However, meticulous evaluation is necessary to detect progressive persistence and clinical recurrence, considering various clinical factors.

Follicular Thyroid Carcinoma in a Country of Endemic Iodine Deficiency (1994-2013)

BACKGROUND

Follicular thyroid cancer (FTC) has historically been linked to iodine deficiency. Although Ghana is among the iodine deficient regions of the world, the proportions, trends, and the clinical features of FTCs have not been studied as a single disease entity. The aim of this study was to determine the relative frequencies, trends, and the clinicopathological characteristics of FTCs among all thyroid malignancies in our institution.

MATERIALS AND METHODS

This was a retrospective study from January 1994 to December 2013. Data were analysed using SPSS software version 23 (Chicago) and Graph pad prism version 5.00.

RESULTS

Follicular thyroid cancer was the second thyroid malignancy (35.0%) and showed a gradual rise in relative proportions over the period. The male-female ratio was 1 : 1.5. The mean ages were 46.9 (SD ±17.3) for males and 46.4 (SD ±13.3) years for females. Enlarged palpable anterior neck swelling was the commonest symptom in males (86.7%) and females (91.3%) (P = 0.730). Hurthle cell carcinoma was the commonest variant of FTC, with 26.7% males and 10.6% females (P = 0.116). Distant spread was found in 23.3% of males compared to 19.1% of females (P = 0.633). The common sites of distant spread were bones (57.2%) in males and cervical lymph nodes (44.4%) in females (P = 0.106).

CONCLUSION

Follicular thyroid cancer was the second common thyroid malignancy (35.0%) with a gradual rise in trend over the study period and male-female ratio of 1.5 : 1. Large anterior neck swelling was the commonest clinical presentation of FTC.

Lymph Node Dissection for Differentiated Thyroid Cancer

Lymph node metastases in differentiated thyroid cancer (DTC) have a wide spectrum of clinical significance. Several variables are taken under consideration when trying to decide on the optimal management of patients with DTC. Routine prophylactic central and/or lateral lymph node dissection is not advocated with exception of central neck dissection for locally advanced tumors. When regarding recurrent disease, foundations have been laid for clinicians to make accurate decisions as to when to perform surgery and when to continue maintaining the patient’s disease under observation. These complex decisions are determined based upon multiple factors, not only regarding the patient’s disease but also the patient’s comprehension of the procedure and apprehension levels. Nevertheless if the patient and/or clinician are emotionally keen to surgically remove the disease then the procedure should be considered.

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.

Anatomic Variability of the Upper Mediastinal Lymph Node Level VII

OBJECTIVE

Lymph node level VII, between the sternal notch and the innominate artery, is a frequent site of lymph node metastases in thyroid cancer. The objective of this study was to determine the cranial-caudal dimensions of level VII in patients undergoing central neck dissection for thyroid cancer and its accessibility through a neck incision only.

PATIENTS AND METHODS

Consecutive patients undergoing central neck dissection for thyroid cancer, with no previous neck dissection, mediastinal or thoracic surgery. The innominate artery was identified and the distance between the sternal notch and the upper border of the artery was measured to the nearest .5 mm. The sizes of level VII were compared with respect to age, sex, height, body mass index, type of neck dissection (therapeutic or prophylactic), and the incidence of previous thyroidectomy.

RESULTS

One-hundred-one consecutive patients (65 women, 36 men, mean age 44 years (range 15-87) underwent prophylactic (n = 55) or therapeutic (n = 46) bilateral central compartment neck dissection. Level VII was accessible via the horizontal neck incision in all cases. Sizes of level VII ranged from 6 cm above the sternal notch to 35 mm below the sternal notch, with a mean distance of 3.5 mm below the sternal notch. The innominate artery was at the level of the sternal notch in 29 patients, and cranial to the sternal notch in 20 cases. No statistical relationship with age, sex, therapeutic/prophylactic neck dissection, previous surgery, body mass index or height was found.

CONCLUSIONS

The maximal distance below the sternal notch was 35 mm. Level VII did not exist in 49 % of patients, and was less than 25 mm caudal to the sternal notch in 95 % of cases. Distinguishing level VII from level VI in thyroid cancer surgery may not be pertinent, due to the ease of access via a classic horizontal neck incision and the small sizes of level VII in the majority of patients.

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.

Central neck dissection in the treatment of well-differentiated thyroid cancer

Therapeutic central compartment neck dissection (CCND) is required for confirmed nodal metastasis in patients with differentiated thyroid cancer. The need for routine prophylactic CCND in patients with papillary thyroid cancer is controversial. This article presents the current evidence to inform the debate against the background of the recommendations of US and British thyroid cancer guidelines. Potential advantages of pCCND include reduced local recurrence, preventing the need for further central compartment surgery and improved staging. Opponents claim that there is no proven patient benefit and that there is increased risk of recurrent laryngeal nerve injury and hypocalcemia.

Surgical approach and outcomes for revision surgery of the central neck compartment

Revision surgery of the central neck compartment is still a controversial subject, and data are scarce in the literature regarding surgical approaches and outcomes. This might be a result of the small number of patients in need of revision of the central neck compartment. Therefore, the purpose of this study was to document the approach and outcomes for revision surgery of the central neck compartment performed in our clinic. The files of patients who had undergone revision surgery of the central neck compartment in the Clinic of Otorhinolaryngology, Ankara Numune Training and Research Hospital, between 2007 and 2013, were evaluated. The subjects included 61 patients who had previously undergone surgical intervention in the central neck compartment and had then undergone bilateral lymph node dissection covering at least levels 6 and 7 in our clinic. Patient ages ranged between 36 and 63 years (mean, 47.2 y; SD = 8.3 y). The complications seen after revision surgery were temporary recurrent laryngeal nerve palsy in 4 patients (6.6%), temporary hypocalcemia in 8 patients (13.1%), and permanent hypocalcemia in 3 patients (4.9%). No permanent recurrent laryngeal nerve damage, wound infection, or hematoma was encountered. Meticulous surgical dissection with identification of the recurrent laryngeal nerve and the implantation site of the parathyroid glands may safeguard against complications. Reoperative surgery in the central compartment of the neck allows the removal of recurrent/persistent disease and has acceptable morbidity.

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.

Carbon nanoparticle-guided central lymph node dissection in clinically node-negative patients with papillary thyroid carcinoma

BACKGROUND

Distinguishing the involved lymph nodes from other tissues during surgery is critical for lymph node dissection. The purpose of this study was to assess the feasibility by using carbon nanoparticles as guidance for lymph node dissection in patients with papillary thyroid carcinoma (PTC).

METHODS

Eighty-one patients were injected with carbon nanoparticles (carbon nanoparticle group), whereas the other 81 patients were not (control group). Routine pathological examination was performed.

RESULTS

The lymph node dissection and metastatic lymph node dissection rates of the carbon nanoparticle group were significantly higher than that of the control group. In the carbon nanoparticle group, the number of mistakenly dissected parathyroid gland, the case number of postoperative hypocalcemia, the case number of postoperative hypoparathyroidism, and the recovery time from hypocalcemia were 4, 6, 8, and 2.33 ± 0.58 weeks, respectively, significantly less than 14, 17, 20, 3, and 3.8 ± 0.92 weeks in the control group (p < .05).

CONCLUSION

Carbon nanoparticles can be applied to more accurately guide the dissection of lymph nodes during thyroidectomy in patients with PTC. © 2015 Wiley Periodicals, Inc. Head Neck 38: 840-845, 2016.

Management of recurrent/persistent nodal disease in patients with differentiated thyroid cancer: a critical review of the risks and benefits of surgical intervention versus active surveillance

BACKGROUND

The primary goals of this interdisciplinary consensus statement are to define the eligibility criteria for management of recurrent and persistent cervical nodal disease in patients with differentiated thyroid cancer (DTC) and to review the risks and benefits of surgical intervention versus active surveillance.

METHODS

A writing group was convened by the Surgical Affairs Committee of the American Thyroid Association and was tasked with identifying the important clinical elements to consider when managing recurrent/persistent nodal disease in patients with DTC based on the available evidence in the literature and the group's collective experience.

SUMMARY

The decision on how best to manage individual patients with suspected recurrent/persistent nodal disease is challenging and requires the consideration of a significant number of variables outlined by the members of the interdisciplinary team. Here we report on the consensus opinions that were reached by the writing group regarding the technical and clinical issues encountered in this patient population.

CONCLUSIONS

Identification of recurrent/persistent disease requires a team decision-making process that includes the patient and physicians as to what, if any, intervention should be performed to best control the disease while minimizing morbidity. Several management principles and variables involved in the decision making for surgery versus active surveillance were developed that should be taken into account when deciding how best to manage a patient with DTC and suspected recurrent or persistent cervical nodal disease.

Management of recurrent cervical papillary thyroid cancer

Papillary thyroid cancer is one of the most common endocrine malignancies, and it is often associated with an excellent prognosis. However, it has been shown to recur in the lymph nodes in the neck. The management of these lymph nodes remains controversial, and current treatment strategies include observation, surgery, radioactive iodine ablation, and percutaneous ethanol injection. These various treatment modalities are discussed in this article.

Best practice for the management of pediatric thyroid cancer

The presentation of differentiated thyroid cancer in children often includes dissemination to lymph nodes. Despite this, the long-term prognosis is excellent with appropriate treatment. A few known hereditary syndromes are associated with paediatric thyroid cancer, although most tumours are sporadic. Ultrasound and cytology is used to evaluate suspect thyroid nodules, and treatment consists of surgery, radioactive iodine and thyroxine suppression therapy. Follow-up includes serum thyroglobulin measurements, serial ultrasounds of the neck, radioiodine whole body scans and occasionally other cross-sectional imaging or positron emission tomography. This review focuses on paediatric well differentiated follicular and papillary thyroid cancer, diagnosis and preoperative evaluation, underlying genetic mechanisms, surgery, other treatment options and follow-up.

Superior mediastinal dissection for papillary thyroid carcinoma: approaches and outcomes

BACKGROUND

Superior mediastinal surgery for thyroid carcinoma is not a standardized procedure like the neck dissection. The objective of this study was to evaluate the effectiveness of superior mediastinal dissection for mediastinal metastasis of papillary thyroid carcinoma (PTC).

METHODS

We conducted a retrospective review of 119 patients who underwent superior mediastinal dissection for the treatment of PTC. The postoperative characteristics and follow-up data were analyzed. Cox regression was performed to identify the factors related to the mediastinal control.

RESULTS

No severe complications occurred in this series. The five-year local (mediastinum) disease-free survival rates of comprehensive (n = 29) and partial (n = 90) superior mediastinal dissection were 86.3 and 84.0%, respectively (log-rank = 0.562; p = 0.452). Different patterns of superior mediastinal dissection did not turn out to be related to mediastinal recurrence in the cox regression. Bilateral paratracheal metastasis was identified as an individual risk factor of mediastinal recurrence with a relative risk value of 4.635 (95% CI: 1.399-15.355; p = 0.012).

CONCLUSIONS

Both partial and comprehensive superior mediastinal dissections are effective and safe for the treatment of mediastinal metastasis of PTC if appropriately designed.

The feasibility and efficacy of secondary neck dissections in thyroid cancer metastases

The purpose of the study was to assess the feasibility of secondary neck dissections (ND) in different types of thyroid cancer (TC), to evaluate the influence of ND extent on morbidity and to describe biochemical and clinical outcomes. 51 patients previously operated for TC (33-well differentiated TC-WDTC, 15 medullary TC-MTC, 3 poorly differentiated TC-PDTC) presenting detectable nodal disease. Reoperations covered I–VII neck levels. Radical neck dissection was performed in 22 patients, selective neck dissection in 29 patients. 14 central compartment (CC), 10 mediastinal and 41 level IV excisions were performed. Postoperative complications occurred in 13 patients: 4 chyle leaks, 3 massive bleedings, 8 permanent vocal cord pareses, hypoparathyroidism in 22 patients (43.1 %), 2 patients expired in perioperative period. In WDTC: in seven patients thyroglobulin level normalized directly after ND, in ten patients in the follow-up; six patients developed distant metastases. None of the patients with MTC achieved calcitonin level <10 pg/ml; nine patients developed distant metastases. None of the patients with PDTC achieved Tg <2 mg/ml; two patients died, the third developed distant metastases. Secondary ND in TC present a challenge by means of surgical approach and possibility of complications. In MTC and PDTC the long-term results were unsatisfactory. In WDTC, the secondary ND should be performed due to strong indications. Metastases localization in levels IV, VI, VII were connected with high complication rate, but these surgeries were crucial for satisfactory oncological outcomes.

Neural Monitored Revision Thyroid Cancer Surgery

Objective

To evaluate the postoperative complications and to evaluate and stratify thyroglobulin (Tg) response associated with revision surgery for thyroid malignancy.

Study Design

Case series with chart review.

Settings

Academic, tertiary care center.

Subjects and Methods

All patients with regionally recurrent thyroid carcinoma and who underwent revision thyroid surgery by the senior author (GWR) during a 5-year period were identified. All patients had pre- and postoperative laryngeal examination and underwent surgery with standardized neural monitoring. Postoperative complications and thyroglobulin (Tg) response were recorded.

Results

One hundred seventeen cases meeting the criteria for revision surgery for recurrent thyroid cancer were identified. Among this group, 30% presented for their third or higher revision procedure. Preoperative permanent vocal cord palsy was present in 14% (n = 16), and 19% (n = 22) had preoperative permanent hypocalcaemia. There were no new cases of either temporary or permanent vocal cord palsy in our study group. Approximately 5% developed temporary and 3% permanent hypocalcaemia requiring medical treatment. The mean basal Tg following revision surgery was 5.6 ng/ml (range, 0.2-32.7), which represented a mean postoperative significant decline in Tg of approximately 90%. In nearly 40%, basal Tg was undetectable postoperatively. Tg response was stratified based on the number of revision surgeries, Tg decline was observed in 90% of all cases, 92% after first revision surgery, 85% after second, 34% after third, and 70% after fifth revision surgeries.

Conclusion

Revision thyroid cancer surgery can be performed with low rates of complications and significant impact on Tg levels even after multiple revision surgeries.

Neglected papillary thyroid carcinoma seven years after initial diagnosis

Papillary thyroid carcinoma (PTC) is the most common epithelial thyroid tumor, accounting for more than 80% of all thyroid tumors. Recent advances in ultrasonographic screening and US-guided fine-needle aspiration biopsy (FNAB) have facilitated the early detection and diagnosis of papillary thyroid carcinomas. In exceptionally rare cases, papillary thyroid tumors may assume enormous dimensions due to recurrent disease or the patient's negligence of the problem. We report an extremely rare case of a 72-year-old woman presented with a neglected giant exophytic papillary thyroid carcinoma with hemorrhagic ulcers. Computed tomography showed a mass measured 17 × 12 cm that caused a displacement of the trachea to the right side and reached the mediastinum. After bleeding management, patient was discharged. The patient was fully aware of her situation, but she denied any further therapeutic management.

Femoral Pathological Fracture as the First Clinical Manifestation of Papillary Thyroid Carcinoma in a Primigravida

Papillary thyroid carcinoma is the most common differentiated type of thyroid malignancy. It is largely a loco-regional disease with a high tendency to metastasize to regional cervical lymph nodes. Distant hematogenous metastases are very rare and primarily include lungs and bones. Distant bone metastases are present in approximately 1.7% of patients with differentiated thyroid malignancy. Sternum, ribs, and spine are the most frequent sites of osseous metastases. Up to our knowledge, we report the first occurrence of an extra nodal metastasis of papillary thyroid carcinoma to a femoral bone presenting as a pathological fracture in a 21-year-old 37-week primigravida. We report this case because of its unusual site of metastasis and atypical presentation during pregnancy. Moreover, we briefly elaborate on the management of such uncommon cases.

Completion lobectomy and central compartment dissection in low-risk patients who had undergone less extensive surgery than hemithyroidectomy

Many low-risk patients with solitary papillary thyroid cancer located in one lobe had undergone surgery that was less extensive than hemithyroidectomy in China. An acceptable completion surgery regimen was suggested for these patients based on our experience. A total of 117 enrolled patients underwent completion surgery. Thirty-two patients had prior tumor resection, 46 patients had prior partial thyroidectomy and 39 patients had prior subtotal thyroidectomy. No neck dissection was performed. Reoperation was scheduled a median of 1.2 months (range, 3 days–6.5 months) after primary surgery for papillary thyroid cancer (PTC). Among the 117 patients, residual tumor was pathologically confirmed in 60 patients, with a residual rate of 51.28%. Among these 60 patients, residual tumor was identified in the thyroid bed alone in 18 patients and in compartment VI alone in 28 patients, while 14 patients exhibited residual tumor in both of these regions. Lymph node metastasis was observed in compartment VI in 42 patients (35.90%), and an average of 6.5 nodes were removed (range, 2–14 nodes for each patient). Additionally, 3.14 positive lymph nodes were removed on average from each of the 42 patients. We conclude that the completion regimen, including the ipsilateral residual lobe, the isthmus and ipsilateral compartment VI (prelaryngeal, pretracheal and paratracheal lymph nodes), is reasonable and acceptable for low-risk patients undergoing surgery that is less extensive than hemithyroidectomy.

Correlation between the number of lymph node metastases and lung metastasis in papillary thyroid cancer

CONTEXT

A prognostic classification system based on aggregate numbers of lymph node metastases may better estimate the risk of distant metastasis.

OBJECTIVE

This investigation sought to evaluate a papillary thyroid cancer (PTC) patient's risk of distant metastasis.

DESIGN

This was a retrospective analysis.

SETTING

The setting was a tertiary referral center.

PATIENTS

Included were 972 PTC patients.

INTERVENTION

The intervention was compartment-oriented surgery.

MAIN OUTCOME MEASURE

The main outcome measure was lung, bone, and liver metastasis.

RESULTS

Eighty-seven (9.0%) of the 972 PTC patients had distant metastases to lung (79 patients), bone (16 patients), liver (two patients), brain and skin (one patient each). For distant metastasis, more than 20 lymph node metastases had a specificity of 90.8% and a negative predictive value of 92.7%, whereas sensitivity and positive predictive value were low (27.6 and 22.9%). On multivariate logistic regression, 1-5, 6-10, and 11-20 involved nodes denoted a moderate risk of lung metastasis [odds ratio (OR), 9.9, 10.6, and 13.8; P ≤ 0.004], whereas more than 20 involved nodes indicated a high risk of lung metastasis (OR, 25.0; P < 0.001). Mediastinal lymph node metastasis carried a moderate risk of lung metastasis (OR, 7.5; P = 0.001). When these numeric categories of lymph node metastases were exchanged for current tumor node metastasis (TNM) N categories, the OR decreased from 25.0 (for > 20 lymph node metastases) to 16.4 (N1b), and from 9.9-13.8 (for 1-20 lymph node metastases) to 4.7 (N1a).

CONCLUSION

In PTC, categories of 0, 1-20, and more than 20 lymph node metastases correlate better with lung metastasis than current TNM N categories N0, N1a, and N1b.

Update in utility of secondary node dissection for papillary thyroid cancer

BACKGROUND

Detection of recurrent/persistent thyroid cancer has improved significantly in the past decade. Disease is detected earlier in recently treated patients and localized in patients long out from initial treatment. This update reviews recent literature regarding the utility of secondary node dissection for papillary thyroid carcinoma. Outcomes include disease-free status measured biochemically and clinically.

RESULTS

The utility of secondary node dissection as measured by clinically detectable disease exceeds 70% for all series and 90% for most. The utility as measured biochemically is more modest, with rates of biochemical cure ranging from 27-81% depending upon strictness of definition and patient selection. In predominately radioiodine scan-negative patients, using the strictest definition of biochemical cure, undetectable stimulated thyroglobulin (Tg) of less than 0.5 ng/ml, a rate of 27% is reported. Biochemical cure rates are reportedly 30-51% for stimulated Tg of less than 2 ng/ml and 56-71% for basal Tg of less than 2 ng/ml, with higher preoperative Tg levels less likely to achieve biochemical cure. Radioiodine-avid disease appears more amenable to cure, with 81% of patients achieving negative stimulated Tg after repeat I131 treatment and radio-assisted surgery. Complication rates of secondary nodal surgery appear similar to initial surgery in experienced hands; however, bilateral reoperative central neck dissection is associated with significantly higher complication rates than unilateral.

SUMMARY

Surgical resolution of clinically detectable disease is likely. Biochemical cure rates are more modest, with the greatest likelihood of biochemical cure occurring in patients with radioiodine-avid disease. In radioiodine-negative patients, there may be a higher likelihood of biochemical cure for those with lower preoperative detectable Tg levels.

Skull metastasis in papillary carcinoma of thyroid: A case report

Papillary thyroid carcinoma with metastasis to the skull is extremely rare. We report a case of unsuspected papillary thyroid carcinoma with skull metastasis. A 48-year-old female patient presenting with painless, pulsatile, progressively increasing swelling in the occipitoparietal region of the scalp approached for an X-ray of the skull. Ultrasound of palpable swelling in the neck revealed a heteroechoic lesion with increased vascularity. Foci of calcification were seen involving both lobes of the thyroid. Ultrasound of scalp showed a destructive mass in the skull with increased vascularity. Biopsy of thyroid lesions revealed branching papillae having a dense fibrovascular core covered by cuboidal epithelial cells with nuclei having a clear ground glass appearance. This case illustrates how isolated extensive skull metastasis can be found in papillary carcinoma patients without causing significant morbidity. Therefore, in the clinical course of thyroid papillary carcinoma, skull metastasis should be considered, and the patients should be meticulously investigated and followed up.

Sentinel lymph node biopsy using carbon nanoparticles for Chinese patients with papillary thyroid microcarcinoma

AIMS

To compare the efficacies of methylene blue (MB) and carbon nanoparticles (CNs) as tracers for sentinel lymph node biopsy (SLNB), and assess the value of SLNB in predicting the cervical LN status of patients with thyroid microcarcinoma.

METHODS

This retrospective analysis comprised 200 thyroid microcarcinoma patients who underwent intraoperative SLNB. Among them, 100 patients were injected with MB dye. The other 100 patients received a CN suspension injection. Routine pathological examination was performed in all resected specimens.

RESULTS

SLNs detected in the experimental and control groups were 126 and 102, respectively, of which the metastatic LNs confirmed by histopathology were 77 and 48, respectively. The staining rate of cervical level VI LNs in the experimental group was significantly higher than that in the control group (P<0.001). For the CN method, the sensitivity, specificity, accuracy rate, and false negative rate were 93.3%, 100%, 97%, and 5.2%, respectively, whereas the corresponding figures for the MB method were 80.6%, 100%, 93%, and 9.9%, respectively. The positive rate of cancer metastases for SLNs in the experimental group was 61.1%, which is significantly higher than that in the control group (47.1%; P=0.034).

CONCLUSIONS

In contrast to the MB method, CNs can maintain the durability of SLN imaging and accurately forecast the LN status of patients with thyroid microcarcinoma; in addition, the CN method was found to be feasible and repeatable. The CN method better aids the screening and selection of patients who are most likely to benefit from cervical LN dissection.

Serum thyroglobulin level measured after thyroxine withdrawal is useful to predict further recurrence in whole body scan-negative papillary thyroid cancer patients after reoperation

The best treatment option for recurrent papillary thyroid carcinoma (PTC) is reoperation when the recurrent lesion is locoregional. The prognostic significance of serum thyroglobulin (Tg) levels before reoperation and the association between the outcome of reoperation and Tg level remain unclear. Our study aimed to determine the outcomes of patients who underwent reoperation and their association with serum Tg levels. We retrospectively studied 79 patients with PTC with locoregional recurrence whose whole-body scan results were negative for any recurrence but whose serum Tg levels were detectable after first-line treatment. All the patients underwent reoperation and follow-up examinations, which involved serial serum Tg measurements after thyroxine withdrawal (T4-off Tg), neck ultrasonography, chest computed tomography, and/or fluorodeoxyglucose-positron emission tomography, to detect further recurrence. During the median follow-up duration of 89 months (range, 38-332 months), 30 patients (38.0%) experienced a second recurrence even after the reoperation. Among all patients, only 12 whose Tg levels decreased postoperatively to undetectable levels showed no recurrence. Most recurrences were detected in the patients with high T4-off Tg levels after the reoperation (T4-off Tg level (ng/mL), number of patients with recurrence, %: <1, 0/12, 0%; 1-10, 9/31, 33.3%; >10, 16/22, 72.7%; P < 0.001). In conclusion, recurrence occurred in 38.0% of the patients even after the reoperation. The postoperative T4-off Tg level was a good indicator of recurrence after the reoperation. Therefore, patients who experience recurrence should undergo follow-up examinations that involve routine measurements of T4-off Tg levels, especially when postreoperative values exceed 10 ng/mL.

Long-term outcome of comprehensive central compartment dissection in patients with recurrent/persistent papillary thyroid carcinoma

BACKGROUND

Persistent or recurrent papillary thyroid carcinoma (PTC) occurs in some patients after initial thyroid surgery and often, radioactive iodine treatment. Here, we identify the efficacy, safety, and long-term outcome of our current surgical management paradigm for persistent/recurrent PTC in the central compartment in an interdisciplinary thyroid cancer clinical and research program at a tertiary thyroid cancer referral center.

METHODS

We retrospectively analyzed our standardized approach of comprehensive bilateral level VI/VII lymph node dissection (SND [VI, VII]) for cytologically confirmed PTC in the central compartment.

RESULTS

From 1994 to 2004, 210 patients, median age 42 (range 12-82) underwent SND (VI, VII). Most patients (106, 51%) had already undergone ≥2 surgical procedures for persistent or recurrent disease, and 31 (15%) had distant metastases at presentation. Postoperatively, 104 (71%) of the 146 patients who were thyroglobulin (Tg) positive had no evidence of disease. Anti-Tg antibodies were present in 38 patients (18%), 17 of whom (53%) did not have anti-Tg antibodies postoperatively. Fourteen patients (7%) were hypoparathyroid at presentation, and 2 more (1%) became permanently hypoparathyroid after surgery. Four patients (2%) experienced recurrent laryngeal nerve paralysis (RLNP) of a previously functioning nerve. Unanticipated RLNP was observed in only one nerve at risk. External beam radiation was given to 33 patients (17%). An additional 17 patients (8%) developed distant metastases during follow-up. At the last follow-up, 130 (66%) of the 196 patients had no detectable Tg; of these, 99 (76%) had no further evidence of disease. A median of 7.25 years after surgery, 167 (90%) of the 185 patients were without evidence of central disease, and 18 (10%) had developed central compartment recurrences within a median interval of 24.3 months. Of those with recurrence, 16 out of 18 patients (89%) underwent a subsequent surgical procedure, thus resulting in an overall 98% central compartment control rate. Kaplan-Meier disease-specific survival at 10 years was 98.9% for patients <45 years old and 77.9% for those ≥45 years old (log-rank p<0.00001). The only predictor of central compartment recurrence was malignancy in a thyroid remnant noted within the central compartment surgical specimen.

CONCLUSIONS

Bilateral comprehensive level VI/VII dissections are safe and effective for long-term control of recurrent/persistent PTC in the central lymphatic compartment.

Central compartment dissection for well differentiated thyroid cancer … and the band plays on

PURPOSE OF REVIEW

The role of central compartment dissection in the surgical management of well differentiated thyroid cancer is controversial. Lack of high-quality prospective studies results in management decisions being based on expert opinions and weaker levels of evidence. The American Thyroid Association has recently revised its management guidelines with particular emphasis on this topic, and a separate working group has set out to define the surgical anatomy that encompasses this procedure.

RECENT FINDINGS

Central compartment dissection comprises the removal of nodal tissue from the prelaryngeal, pretracheal and paratracheal compartments, with no role for berry-picking procedures. There is universal agreement that therapeutic nodal dissection should be performed in patients with metastatic disease detected either through preoperative imaging or during intraoperative evaluation of the central compartment, with either visual inspection or frozen-section pathology. In contrast, there may be limited benefit from routine prophylactic central compartment dissection, for either disease recurrence or survival outcomes. As such, it should be performed only in patients deemed high risk: larger tumors, extra-thyroidal extension or aggressive histologic subtypes.

SUMMARY

Future studies should focus on identifying the subpopulation of patients who would most benefit from these procedures and spare low-risk patients from the unwanted complications.

The role of prophylactic central neck dissection in differentiated thyroid carcinoma: issues and controversies

Prophylactic central neck dissection (pCND) in differentiated thyroid carcinoma (DTC) is one of the most controversial surgical subjects in recent times. To date, there is little evidence to support the practice of pCND in patients with DTC undergoing total thyroidectomy. Although the recently revised American Thyroid Association (ATA) guideline has clarified many inconsistencies regarding pCND and has recommended pCND in “high-risk” patients, many issues and controversies surrounding the subject of pCND in DTC remain. The recent literature has revealed an insignificant trend toward lower recurrence rate in patients with DTC who undergo total thyroidectomy and pCND than those who undergo total thyroidectomy alone. However, this was subjected to biases, and there are concerns whether pCND should be performed by all surgeons who manage DTC because of increased surgical morbodity. Performing a unilateral pCND may be better than a bilateral pCND given its lower surgical morbidity. Further studies in this controversial subject are much needed.

Clinical impact of cervical lymph node involvement and central neck dissection in patients with papillary thyroid carcinoma: a retrospective analysis of 368 cases

The impact of cervical lymph node metastases and the optimal surgical management of the neck in patients with papillary thyroid carcinoma (PTC) remain controversial. The objectives of this retrospective study were to determine, in patients with PTC, the predictive factors and the impact on tumor recurrence rate of cervical lymph node involvement, and to evaluate the oncologic results and the morbidity of central neck dissection (CND). We reviewed the records of patients who had undergone surgical treatment for PTC at our institution between 1990 and 2000. A total of 368 patients (86 men and 282 women) were included in this study. Young age (p = 0.02), tumor size (p = 0.001) and extrathyroidal tumor extension (p = 0.003) were significant predictive factors of cervical lymph node metastatic involvement (multivariate analysis). Initial metastatic cervical lymph node involvement was identified as an independent risk factor of tumor recurrence (multivariate analysis, p = 0.01). Metastatic lymph node(s) were found in prophylactic CND specimens in 31% of the patients. CND increased the risk of postoperative hypocalcemia (p = 0.008) and of permanent hypoparathyroidism (p = 0.002). In conclusion, cervical lymph node metastatic involvement at the time of initial surgery is an independent risk factor of tumor recurrence. CND provided an up-staging of more than 30% of patients with a clinically N0 neck, but was associated with significant morbidity regarding parathyroid function.

An individualized approach to the child with thyroid cancer

Children with differentiated thyroid cancer (DTC) often present with extensive disease that inclined clinicians in prior decades toward aggressive treatment including total thyroidectomy, radical neck dissection and universal prescription of radioactive iodine (RAI). Recent series with 40 years of follow-up have shown that fewer than 2% of children ultimately die from DTC, but they may have increased all-cause mortality from second malignancies that might be related to previous radiation exposure. In this article, we review data to support the notion that an individualized, risk-stratified approach to therapy should be used for children with DTC. Ideally this will provide aggressive therapy for those in whom aggressive treatment is warranted, but withhold aggressive and risk-associated therapy from those who are not likely to benefit.

Considerations for personalized surgery in patients with papillary thyroid cancer

BACKGROUND

Personalizing treatment for papillary thyroid cancer (PTC) requires a multidisciplinary approach. The surgical management of PTC has long been based on retrospective studies focusing on endpoints that are of debatable significance. There is considerable debate in the literature regarding the optimal initial treatment for PTC. Many of these issues are discussed in this review. These debates have hindered the development of a tailored treatment strategy.

SUMMARY

The ability to optimally personalize a surgical plan for the treatment of PTC is ultimately dependent on an understanding of the biological behavior of that individual patient's tumor. We are at the genesis of an age where molecular biology advances endeavor to profile a patient's tumor behavior. This review summarizes current strategies for managing PTC, where we are with personalizing surgery for these patients, and where we hope to go. Thyroid surgery is one of the newest fields for the application of minimally invasive techniques and can now be accomplished endoscopically or with robotic assistance in many patients who therefore may benefit from these alternative approaches.

CONCLUSION

When treating a patient with PTC, it seems prudent to weigh the many factors discussed in this review to individualize the most optimal surgical plan.

Long-term efficacy of lymph node reoperation for persistent papillary thyroid cancer

OBJECTIVE

The objective of the study was to determine the outcome of surgical resection of metastatic papillary thyroid cancer (PTC) in cervical lymph nodes after failure of initial surgery and I(131) therapy.

DESIGN

This was a retrospective clinical study.

SETTING

The study was conducted at a university-based tertiary cancer hospital.

PATIENTS

A cohort of 95 consecutive patients with recurrent/persistent PTC in the neck underwent initial reoperation during 1999-2005. All had previous thyroidectomy (+/-nodal dissection) and I(131) therapy. Twenty-five patients with antithyroglobulin (Tg) antibodies were subsequently excluded.

MAIN OUTCOME MEASURES

Biochemical complete remission (BCR) was stringently defined as undetectable TSH-stimulated serum Tg.

RESULTS

A total of 107 lymphadenectomies were undertaken in these 70 patients through January 2010. BCR was initially achieved in 12 patients (17%). Of the 58 patients with detectable postoperative Tg, 28 had a second reoperation and BCR was achieved in five (18%), seven had a third reoperation, and none achieved BCR. No patient achieving BCR had a subsequent recurrence after a mean follow-up of 60 months (range 4-116 months). In addition, two more patients achieved BCR during long-term follow-up without further intervention. In total, 19 patients (27%) achieved BCR and 32 patients (46%) achieved a TSH-stimulated Tg less than 2.0 ng/ml. Patients who did not achieve BCR had significant reduction in Tg after the first (P < 0.001) and second (P = 0.008) operations. No patient developed detectable distant metastases or died from PTC.

CONCLUSIONS

Surgical resection of persistent PTC in cervical lymph nodes achieves BCR, when most stringently defined, in 27% of patients, sometimes requiring several surgeries. No biochemical or clinical recurrences occurred during follow-up. In patients who do not achieve BCR, Tg levels were significantly reduced. The long-term durability and impact of this intervention will require further investigation.

Management of thyroid nodules and surgery for differentiated thyroid cancer

The incidence of well-differentiated thyroid cancer has seen a worldwide increase in the last three decades. Whether this is due to a 'true increase' in incidence or simply increased detection of otherwise subclinical disease remains unclear. The treatment of thyroid cancer revolves around appropriate surgical intervention, minimising complications and the use of adjuvant therapy in select circumstances. Prognostic features and risk stratification are crucial in determining the appropriate treatment. There continues to be considerable debate in several aspects of management in these patients. Level 1 evidence is lacking, and there are limited prospective data to direct therapy, hence limiting decision-making to retrospective analyses, treatment guidelines based on expert opinion and personal philosophies. This overview focuses on the major issues associated with the investigation of thyroid nodules and the extent of surgery. As overall survival in well-differentiated thyroid cancer exceeds 95%, it is important to reduce over-treating the large majority of patients, and focus limited resources on high-risk patients who require aggressive treatment and closer attention. The onus is on the physician to avoid treatment-related complications from thyroid surgery and to offer the most efficient and cost-effective therapeutic option.

To stimulate or withdraw? A cost-utility analysis of recombinant human thyrotropin versus thyroxine withdrawal for radioiodine ablation in patients with low-risk differentiated thyroid cancer in the United States

CONTEXT

Use of recombinant human TSH (rhTSH) prior to radioactive iodine remnant ablation for patients with differentiated thyroid cancer avoids the hypothyroid state and improves quality of life. European studies have shown that use of rhTSH vs. thyroid hormone withdrawal is a cost-effective method for preparing patients for ablation.

OBJECTIVE

The objective of the study was to determine the cost-utility of rhTSH prior to ablation in the United States.

DESIGN/SETTING/SUBJECTS

A Markov decision model was developed for a hypothetical group of adult patients with low-risk differentiated thyroid cancer who were prepared for ablation by either rhTSH or thyroid hormone withdrawal. Patients entered the model after initial thyroidectomy; follow-up was in accordance with current American Thyroid Association guidelines. Input data were obtained from the literature, Medicare reimbursement schedule, and U.S. Bureau of Labor Statistics. Sensitivity analyses were performed for all clinically relevant inputs.

MAIN OUTCOME MEASURES

Cost-utility, measured in U.S. dollars per quality-adjusted life-year ($/QALY), was measured.

RESULTS

Use of rhTSH yielded an incremental cost-utility of $52,554/QALY (95% confidence interval $52,058-53,050/QALY) (incremental societal cost of $1,365/patient; incremental benefit of 0.026 QALY/patient). The majority of cost and benefit occurs during the preablation, ablation, and postablation period; differences in cost are due to cost of rhTSH and differences in productivity loss (days off work). The model was most sensitive to changes in time off work, cost of rhTSH, and differences in utilities of health states.

CONCLUSIONS

In the United States, the cost-effectiveness of rhTSH for ablation in patients with low-risk differentiated thyroid cancer is highly dependent on potential variations in cost of rhTSH, rates of remnant ablation, time off work, and quality of life.