Thyroid lobe ablation with radioactive iodine as an alternative to completion thyroidectomy after hemithyroidectomy in patients with follicular thyroid carcinoma: long-term follow-up

[Hemithyroidectomy or total thyroidectomy for low-risk papillary thyroid cancer? : Surgical criteria for primary and secondary choice of treatment in an interdisciplinary treatment concept]

The increase in small intrathyroid papillary thyroid cancer (PTC) observed worldwide over the past two decades, with no increase in cancer-specific mortality, has challenged the previous concept of total thyroidectomy as a one-size-fits-all panacea. After exclusion of papillary microcarcinomas, a systematic review of 20 clinical studies published since 2002, which compared hemithyroidectomy (HT) to total thyroidectomy (TT), found comparable long-term oncological outcomes for low-risk papillary thyroid cancer (LRPTC) 1-4 cm in diameter, whereas postoperative complication rates were markedly lower for HT. To refine individual treatment plans, HT should be combined with ipsilateral central lymph node dissection and intraoperative frozen section analysis for staging. Based on recent evidence from studies and in consideration of individual risk factors, patients with LRPTC can be offered the concept of HT as an alternative to the standard TT. A prerequisite for the treatment selection and decision is a comprehensive patient clarification of the possible advantages and disadvantages of both approaches.

Propensity Score Matched Outcome Analysis of Lobar Ablation Versus Completion Thyroidectomy in Low-Risk Differentiated Thyroid Cancer Patients: Median Follow-Up of 11 Years

Background: Radioactive iodine lobar ablation (RAILA) of the contralateral thyroid lobe has been suggested as an alternative to completion thyroidectomy in patients of differentiated thyroid cancer (DTC) who underwent initial hemithyroidectomy. However, data on long-term outcomes are scarce. In this study, we intended to describe the long-term outcomes of RAILA versus completion thyroidectomy in a cohort of low-risk DTC patients. Methods: Data of patients with low-risk DTC who underwent initial hemithyroidectomy, and were subsequently treated with either completion thyroidectomy or RAILA between 1996 and 2015, were collected and analyzed. The treatment outcomes included ablation rate, recurrence rate, recurrence-free survival (RFS), and adverse events, and were validated by propensity score matching analysis. Results: Of the 1243 patients (median age: 34 years, range: 5-78) with low-risk DTC, 514 patients underwent upfront RAILA while 729 patients underwent completion thyroidectomy followed by remnant ablation. The ablation rate following the first radioactive iodine (¹³¹I) cycle was 75.3% [95% confidence interval (CI) 71.3-78.9] in the RAILA group versus 84.1% [CI 81.2-86.6] in the completion thyroidectomy group (p < 0.001). Over median follow-up of 11.4 years (interquartile range: 8.3-15.8), the recurrence rates between the two groups were not significantly different (1.6% [CI 0.7-3.2] vs. 1.0% [CI 0.4-2.1], respectively, p = 0.343). The product limit estimate of RFS at 10 years was 98.6% [CI 97.6-99.6%] in the RAILA group versus 99.1% [CI 98.3-99.9%] in the completion thyroidectomy group (p = 0.391). The outcomes in 497 matched pairs generated through propensity score analysis were similar. None of the patients in the RAILA group experienced permanent hypocalcemia or recurrent laryngeal nerve palsy, while the corresponding rates in the completion thyroidectomy group were 10/729 (1.4%) (p = 0.006) and 5/729 (0.7%) (p = 0.080), respectively. Radiation thyroiditis was seen in 25/514 (4.9%) patients in the RAILA group versus 3/729 (0.4%) in the completion thyroidectomy group (p < 0.001). Conclusions: Upfront RAILA is seen to be a noninvasive, safe, and effective alternative to surgical completion thyroidectomy in low-risk DTC patients in the absence of macroscopic malignancy in the remaining thyroid lobe.

Case for staged thyroidectomy

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

Radioiodine Ablation of Remaining Thyroid Lobe in Patients with Differentiated Thyroid Cancer Treated by Lobectomy: A Systematic Review and Metaanalysis

We aimed to conduct a systematic review and metaanalysis of studies reporting the performance of radioactive iodine (¹³¹I) therapy in differentiated thyroid cancer (DTC) patients requiring a completion treatment after lobectomy. We also evaluated the response to ¹³¹I therapy according to 2015 American Thyroid Association guidelines and the adverse events. Methods: A specific search strategy was designed to find articles evaluating the use of ¹³¹I in patients with evidence of DTC after lobectomy. PubMed, Cochrane Central Register of Controlled Trials, Scopus, and Web of Science were searched. The search was updated until January 2020, without language restriction. Data were cross-checked and any discrepancy discussed. A proportion metaanalysis (with 95% confidence interval) was performed using the random-effects model. Metaregressions on ¹³¹I success were attempted. Results: The pooled success ablation rate was 69%, with better results in patients receiving a single administration of about 3.7 GBq; high heterogeneity was found (I² test, 85%), and publication bias was absent (Egger test, P = 0.57). Incomplete structural responses were recorded in only 14 of 695 (2%) patients enrolled in our analysis. Incomplete biochemical responses were observed in 8%-24% of patients, with higher rates (24%) in patients receiving low radioiodine activities (∼1.1 GBq) and lower rates (8%-18%) in patients receiving higher activities of radioiodine (∼3.7 GBq). Neck pain due to thyroiditis was reported in up to 18% of patients, but in most cases, symptoms resolved after oral paracetamol or a short course of prednisone. Conclusion: Lobar ablation with ¹³¹I is effective, especially when high ¹³¹I activities are used. However, the rate of incomplete biochemical response to initial treatment appears to be slightly higher than in the classic scheme of initial treatment of DTC. Radioisotopic lobectomy should be considered for patients with low- to intermediate-risk DTC requiring completion treatment after lobectomy due to specific individual risk factors or patient preferences.

The role of radioactive iodine in the management of patients with differentiated thyroid cancer - An oncologic surgical perspective

With improved understanding of the biology of differentiated thyroid carcinoma its management is evolving. The approach to surgery for the primary tumour and elective nodal surgery is moving from a "one-size-fits-all" recommendation to a more personalised approach based on risk group stratification. With this selective approach to initial surgery, the indications for adjuvant radioactive iodine (RAI) therapy are also changing. This selective approach to adjuvant therapy requires understanding by the entire treatment team of the rationale for RAI, the potential for benefit, the limitations of the evidence, and the potential for side-effects. This review considers the evidence base for the benefits of using RAI in the primary and recurrent setting as well as the side-effects and risks from RAI treatment. By considering the pros and cons of adjuvant therapy we present an oncologic surgical perspective on selection of treatment for patients, both following pre-operative diagnostic biopsy and in the setting of a post-operative diagnosis of malignancy.

Completion Thyroidectomy: Safer than Thought

BACKGROUND

The aim of this study was to find out whether a substantial difference in terms of complication rates exists between primary and completion thyroidectomies following initial bilateral subtotal thyroidectomy in the light of current literature and our series.

PATIENTS AND METHODS

Total number of 696 patients who received completion thyroidectomy (Group 1, n = 289) and total thyroidectomy for differentiated thyroid cancer (Group 2, n = 407) and their data were reviewed and postoperative complications were compared between the groups and with the literature.

RESULTS

Transient and permanent hypocalcaemia rates were 20% and 5.8% in Group 1 and 10.5% and 5.1% for Group 2 respectively. Unilateral transient, bilateral transient and unilateral permanent recurrent laryngeal nerve palsy rates were 6.2%, 1.3% and 4.4% for patients in Group 1 whereas same complications were seen in 4.6%, 0.7% and 3.6% of patients in Group 2. When groups were compared for complications; temporary hypocalcaemia, unilateral temporary nerve palsy, and minor wound infection rates were statistically higher in Group 1, with no significant difference in permanent complications.

CONCLUSION

When complication rates of re-operation after bilateral subtotal thyroidectomy and primary total thyroidectomy for differentiated thyroid cancer were compared in an unbiased fashion, completion thyroidectomy was shown to be as safe as a primary operation with regard to permanent complications.

Surgical options for thyroid cancer and post-surgical management

INTRODUCTION

Differentiated thyroid cancer (DTC), which includes papillary and follicular, is the most common type of thyroid cancer and the incidence is rising. Survival rates of DTC are excellent, so the focus of management should be to optimize the initial oncological surgical resection, while providing follow up and adjunct therapies to improve long-term outcomes.

AREAS COVERED

It is important for providers to be aware of the most recent guidelines for DTC management, as practices have changed in recent years. In this review, we will highlight some of the updates in the American Thyroid Association (ATA) guidelines and the American Joint Committee on Cancer (AJCC) edition changes in order to better guide practitioners in the management of the evolving treatment strategies. Management of DTC includes diagnosis of thyroid nodules, defining the best operative or non-operative treatment for patients using a multidisciplinary approach, and surveillance of DTC to optimize patients in terms of both clinical and quality of life outcomes.

EXPERT COMMENTARY

As the rate of DTC rises yet the mortality remains stable, management focuses on disease-free follow up and optimal long-term outcomes. Current controversies in management of DTC include proper oncological surgery depending on the nature and size of the DTC, the cytopathology nomenclature, management of lymph node disease, and appropriate surveillance strategies. Preoperative risk stratification is key. We have many modalities to aid in that stratification, such as identifying known concerning features of nodules with expert-performed ultrasound, thyroglobulin (Tg) levels, molecular testing, and evidence based outcomes data for recurrence rates. However, many individual cases still present with multiple management options, thus highlighting the importance of patient discussion and a multidisciplinary approach. It is important for providers to recognize that the short and long-term follow up must be guided by surveillance studies, and patients need to be re-risk stratified in order to optimize detection of recurrence yet sustain quality of life.

Current Guidelines for Postoperative Treatment and Follow-Up of Well-Differentiated Thyroid Cancer

Well-differentiated thyroid cancer is increasing in incidence but the disease-specific mortality remains very low. The only effective adjuvant treatment is radioactive iodine ablation. Guidelines regarding the use and dosage of radioactive iodine depend on pathologic features of the primary and metastatic tumor that define risk. Long-term treatment includes thyroid-stimulating hormone suppression and surveillance with serum thyroglobulin and radiologic assessment for nodal recurrence.

Re-ablation I-131 activity does not predict treatment success in low- and intermediate-risk patients with differentiated thyroid carcinoma

The aim of this study was to evaluate the efficacy of different radioactive iodine (I-131) activities used for re-ablation, to compare various combinations of treatment activities, and to identify predictors of re-ablation failure in low- and intermediate-risk differentiated thyroid carcinoma (DTC) patients. The study included 128 consecutive low- and intermediate-risk patients with DTC with ablation failure after total thyroidectomy. Patient characteristics, T status, tumor size, lymph node involvement, postoperative remnant size on whole-body scintigraphy, serum thyroglobulin (Tg), thyroid-stimulating hormone (TSH), anti-Tg antibody (TgAb), and Tg/TSH ratio were analyzed as potential predictors of the re-ablation success. Re-ablation was successful in 113 out of 128 patients (88.3 %). Mean first I-131 activity was 2868 ± 914 MBq (77.5 ± 24.7 mCi) and mean second I-131 activity 3004 ± 699 MBq (81.2 ± 18.9 mCi). There was no association between the first, second, and cumulative activity with re-ablation treatment outcome. Treatment failure was associated with higher Tg levels prior to re-ablation (Tg2) (OR 1.16, 95 % CI 1.05-1.29, P = 0.003) and N1a status (OR 3.89, 95 % CI 1.13-13.41, P = 0.032). After excluding patients with positive-to-negative TgAb conversion, Tg2 level of 3.7 ng/mL predicted treatment failure with a sensitivity of 75.0 %, specificity of 80.5 %, and a negative predictive value of 97.1 %. Patients with positive-to-negative TgAb conversion had higher failure rates (OR 2.96, 95 % CI 0.94-9.29). Re-ablation success was high in all subgroups of patients and I-131 activity did not influence treatment outcome. Tg may serve as a good predictor of re-ablation failure. Patients with positive-to-negative TgAb conversion represent a specific group, in whom Tg level should not be used as a predictive marker of treatment outcome.

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.

Treatment of thyroid follicular carcinoma

Differentiated thyroid carcinoma includes 2 different tumor types, papillary (PC) and follicular carcinoma (FC), and although similar, their prognosis is different. FC is uncommon, and this has led to it often being analyzed together with PC, and therefore the true reality of this tumor is difficult to know. As a result, the diagnostic and therapeutic management and the prognostic factors in differentiated carcinoma are more predictive of PC than FC. In this review we analyze the current state of many of the therapeutic aspects of this pathology. The best surgical technique and the usefulness of associated lymphadenectomy is also analyzed. Regarding post-surgical ablation with 131I, the indications, doses and usefulness are discussed. For the remaining therapies we analyze the few indications for radiotherapy and chemotherapy, and of new drugs such as tyrosine kinase inhibitors.

Revisiting the guidelines issued by the Japanese Society of Thyroid Surgeons and Japan Association of Endocrine Surgeons: a gradual move towards consensus between Japanese and western practice in the management of thyroid carcinoma

BACKGROUND

In 2010, the Japanese Society of Thyroid Surgeons (JSTS) and Japanese Association of Endocrine Surgeons (JAES) established new guidelines entitled "Treatment of Thyroid Tumors." Since then, several new studies, including those that address the treatment of differentiated thyroid carcinoma (DTC) have been published, and the DTC treatment policy not only of Japanese physicians but those in Western countries has continued to evolve.

METHODS

We selected six clinical questions regarding the treatment of DTC and revisited them based on newly published data from Western countries and Japan.

RESULTS

More data have accumulated about treatment of low-risk papillary microcarcinoma. It has become clear that conservative treatment (observation) of low-risk papillary microcarcinoma in elderly patients is an acceptable alternative to immediate surgery. Total thyroidectomy versus hemithyroidectomy for low-risk papillary thyroid carcinoma (PTC) has become an important issue, and some publications after 2010 indicated that hemithyroidectomy is adequate for these low-risk patients. Unfortunately, no published manuscripts on prophylactic central node dissection offered good evidence regarding its indications or included a large number of patients. Also, it was not evident that prophylactic lateral node dissection improves cause-specific survival, although it might reduce lymph node recurrence especially in PTC patients with large tumors, distant metastases, or clinical central node metastases. Although completion total thyroidectomy was not recommended for minimally invasive follicular thyroid carcinoma in our guidelines, it may be better to perform it in elderly patients and those with a large tumor or extensive vascular invasion. Radioactive iodine (RAI) ablation after total thyroidectomy is still performed almost routinely in many Western institutions, although recent studies showed that ablation is not beneficial in low-risk patients. In Japan, because of legal restrictions, most patients did not undergo RAI ablation, and their prognoses are excellent.

CONCLUSIONS

Recently, policy for treating DTCs has changed not only in Western countries but also in Japan, resulting in a gradual move toward consensus between Western practice and ours. We will continue to present the best treatments for patients with thyroid carcinoma each time we revise our guidelines.

Use of radioiodine after thyroid lobectomy in patients with differentiated thyroid cancer: does it change outcomes?

BACKGROUND

Radioiodine (RAI) lobe ablation in lieu of completion thyroidectomy is not recommended. This study describes RAI use patterns and outcomes in patients with well-differentiated thyroid cancer (DTC) after thyroid lobectomy (TL).

STUDY DESIGN

A total of 170,330 patients diagnosed with DTC between 1998 and 2011 were identified using the National Cancer Database. Demographic, tumor, and treatment variables were analyzed using both univariate and multivariate regression.

RESULTS

A total of 32,119 patients (20%) underwent TL as the definitive procedure. Mean age at diagnosis was 48 years, median tumor size was 1 cm, 4% had extrathyroidal extension, 4% had positive lymph nodes, and <1% distant metastases. Radioiodine was administered to 24% of patients in the TL cohort and represented 10% of the overall RAI use. In multivariate analysis, RAI use was associated with age younger than 45 years (odds ratio [OR] = 1.51), community facilities (OR = 1.26), ≥ 1 cm tumors (OR = 5.67), stage II (OR = 1.54) or III (OR = 2.05), positive lymph nodes (OR = 1.78), and extrathyroidal extension (OR = 1.36). On both univariate and multivariate analysis, RAI after TL was associated with improved survival at both 5 and 10 years follow-up (97% vs 95% and 91% vs 89%, respectively; hazard ratio = 0.53; 95% CI, 0.38-0.72; p < 0.001) CONCLUSIONS: Nearly one quarter of TL patients received RAI. The strongest predictors of RAI use were larger cancers and advanced stage. Use of RAI in these patients was associated with improved overall survival. Future studies and guidelines will need to more clearly address this practice and educate providers about the appropriate use of RAI in TL patients.

German Association of Endocrine Surgeons practice guideline for the surgical management of malignant thyroid tumors

INTRODUCTION

Over the past years, the incidence of thyroid cancer has surged not only in Germany but also in other countries of the Western hemisphere. This surge was first and foremost due to an increase of prognostically favorable ("low risk") papillary thyroid microcarcinomas, for which limited surgical procedures are often sufficient without loss of oncological benefit. These developments called for an update of the previous practice guideline to detail the surgical treatment options that are available for the various disease entities and tumor stages.

METHODS

The present German Association of Endocrine Surgeons practice guideline was developed on the basis of clinical evidence considering current national and international treatment recommendations through a formal expert consensus process in collaboration with the German Societies of General and Visceral Surgery, Endocrinology, Nuclear Medicine, Pathology, Radiooncology, Oncological Hematology, and a German thyroid cancer patient support organization.

RESULTS

The practice guideline for the surgical management of malignant thyroid tumors includes recommendations regarding preoperative workup; classification of locoregional nodes and terminology of surgical procedures; frequency, clinical, and histopathological features of occult and clinically apparent papillary, follicular, poorly differentiated, undifferentiated, and sporadic and hereditary medullary thyroid cancers, thyroid lymphoma and thyroid metastases from primaries outside the thyroid gland; extent of thyroidectomy; extent of lymph node dissection; aerodigestive tract resection; postoperative follow-up and surgery for recurrence and distant metastases.

CONCLUSION

These evidence-based recommendations for surgical therapy reflect various "treatment corridors" that are best discussed within multidisciplinary teams and the patient considering tumor type, stage, progression, and inherent surgical risk.