Remnant uptake as a postoperative oncologic quality indicator

Thyroglobulin measurement is the most powerful outcome predictor in differentiated thyroid cancer: a decision tree analysis in a European multicenter series

OBJECTIVES

An accurate prognostic assessment is pivotal to adequately inform and individualize follow-up and management of patients with differentiated thyroid cancer (DTC). We aimed to develop a predictive model for recurrent disease in DTC patients treated by surgery and 131I by adopting a decision tree model.

METHODS

Age, sex, histology, T stage, N stage, risk classes, remnant estimation, thyroid-stimulating hormone (TSH), thyroglobulin (Tg), administered 131I activities and post-therapy whole body scintigraphy (PT-WBS) were identified as potential predictors and put into regression algorithm (conditional inference tree, c-tree) to develop a risk stratification model for predicting persistent/recurrent disease over time.

RESULTS

The PT-WBS pattern identified a partition of the population into two subgroups (PT-WBS positive or negative for distant metastases). Patients with distant metastases exhibited lower disease-free survival (either structural, DFS-SD, and biochemical, DFS-BD, disease) compared to those without metastases. Meanwhile, the latter were further stratified into three risk subgroups based on their Tg values. Notably, Tg values >63.1 ng/mL predicted a shorter survival time, with increased DFS-SD for Tg values <63.1 and <8.9 ng/mL, respectively. A comparable model was generated for biochemical disease (BD), albeit different DFS were predicted by slightly different Tg cutoff values (41.2 and 8.8 ng/mL) compared to DFS-SD.

CONCLUSIONS

We developed a simple, accurate and reproducible decision tree model able to provide reliable information on the probability of structurally and/or biochemically persistent/relapsed DTC after a TTA. In turn, the provided information is highly relevant to refine the initial risk stratification, identify patients at higher risk of reduced structural and biochemical DFS, and modulate additional therapies and the relative follow-up.

The impact of intraoperative neural monitoring during papillary thyroid cancer surgery on completeness of thyroidectomy and thyroglobulin response: a propensity-score matched study

BACKGROUND

Intraoperative neural monitoring (IONM) has been utilized for a variety of thyroid pathologies, including papillary thyroid carcinoma (PTC). Remnant thyroid tissue following total thyroidectomy (TT) in patients with PTC is associated with increased recurrence. The aim of this study is to investigate whether the use of IONM in PTC surgery has an impact on the completeness of thyroidectomy.

METHODS

Retrospectively, patients with preoperative diagnosis of PTC, who underwent TT in a tertiary center were reviewed. They were grouped based on the IONM usage, and 1:1 propensity-score match was performed. Primary outcome was the completeness of thyroidectomy, determined by measuring postoperative stimulated thyroglobulin levels (sTg).

RESULTS

Among 274 clinically node-negative PTC patients who underwent TT and ipsilateral prophylactic central lymph-node dissection, a total of 170 patients (85:85) were matched. Postoperative sTg levels were significantly lower in the IONM group (1 ng/dL vs. 0.4 ng/dL; p < 0.01) with higher percentage of the patients with sTg levels <1 ng/ml (50.6% vs. 69.4%; p = 0.01). More patients in the no-IONM group received RAI ablation with significantly higher doses (mean mci: 120 vs. 102; p = 0.02).

CONCLUSION

The use of IONM during thyroidectomy provides improvement in the completeness of thyroidectomy and reduction in postoperative sTg levels which can be used as a guide by clinicians to avoid RAI ablation in selected PTC patients and to adjust low ablative doses in patients who are scheduled for remnant ablation.

Theranostics of Thyroid Cancer

Molecular imaging is pivotal in evaluating and managing patients with different thyroid cancer histotypes. The existing, pathology-based, risk stratification systems can be usefully refined, by incorporating tumor-specific molecular and molecular imaging biomarkers with theranostic value, allowing patient-specific treatment decisions. Molecular imaging with different radioactive iodine isotopes (ie, I131, I123, I124) is a central component of differentiated carcinoma (DTC)'s risk stratification while [18F]F-fluorodeoxyglucose ([18F]FDG) PET/CT is interrogated about disease aggressiveness and presence of distant metastases. Moreover, it is particularly useful to assess and risk-stratify patients with radioiodine-refractory DTC, poorly differentiated, and anaplastic thyroid cancers. [18F]F-dihydroxyphenylalanine (6-[18F]FDOPA) PET/CT is the most specific and accurate molecular imaging procedure for patients with medullary thyroid cancer (MTC), a neuroendocrine tumor derived from thyroid C-cells. In addition, [18F]FDG PET/CT can be used in patients with more aggressive clinical or biochemical (ie, serum markers levels and kinetics) MTC phenotypes. In addition to conventional radioiodine therapy for DTC, new redifferentiation strategies are now available to restore uptake in radioiodine-refractory DTC. Moreover, peptide receptor theranostics showed promising results in patients with advanced and metastatic radioiodine-refractory DTC and MTC, respectively. The current appropriate role and future perspectives of molecular imaging and theranostics in thyroid cancer are discussed in our present review.

Factors Affecting Ablation Success After I-131 Radioactive Iodine Therapy in Low and Intermediate Risk Papillary Thyroid Cancer

The study was to evaluate the effect of radioactive iodine (RAI) treatment application time and clinical, histopathological factors on ablation success in patients with operated papillary thyroid cancer (PTC) in low and intermediate-risk. One hundred sixty-one patients with PTC in the low and intermediate-risk were evaluated. Most patients (89.4%) were in the low-risk, and 10.6% were in the intermediate-risk. When the patients were divided into two groups according to the date of receiving RAI treatment after surgery, those who received early treatment (≤3 months) constituted the majority of the patients (72.7%). Seventeen patients received 1.85 Gigabecquerel (GBq), 119 3.7 GBq, 25 5.55 GBq RAI. Most patients (82%) achieved ablation success after the first RAI treatment. The time interval between surgery and RAI treatment did not affect ablation success. Stimulated Tg level measured on the RAI treatment day was an independent predictive factor for successful ablation (p<0.001). The cut-off value of Tg found to predict ablation failure was 5.86 ng/ml. It was concluded that 5.55 GBq RAI treatment could predict ablation success compared to 1.85 GBq dose (p=0.017). It was concluded that having a T1 tumor may predict treatment success compared to a T2 or T3 tumor (p=0.001, p<0.001, retrospectively). The time interval does not affect ablation success in low and intermediate-risk PTC. The ablation success rate may decrease in patients who receive low-dose RAI and have high Tg levels before treatment. The most crucial factor in achieving ablation success is giving enough doses of RAI to ablate the residual tissue.

Postoperative thyroglobulin as a yard-stick for radioiodine therapy: decision tree analysis in a European multicenter series of 1317 patients with differentiated thyroid cancer

PURPOSE

An accurate postoperative assessment is pivotal to inform postoperative 131I treatment in patients with differentiated thyroid cancer (DTC). We developed a predictive model for post-treatment whole-body scintigraphy (PT-WBS) results (as a proxy for persistent disease) by adopting a decision tree model.

METHODS

Age, sex, histology, T stage, N stage, risk classes, remnant estimation, TSH, and Tg were identified as potential predictors and were put into regression algorithm (conditional inference tree, ctree) to develop a risk stratification model for predicting the presence of metastases in PT-WBS.

RESULTS

The lymph node (N) stage identified a partition of the population into two subgroups (N-positive vs N-negative). Among N-positive patients, a Tg value  > 23.3 ng/mL conferred a 83% probability to have metastatic disease compared to those with lower Tg values. Additionally, N-negative patients were further substratified in three subgroups with different risk rates according to their Tg values. The model remained stable and reproducible in the iterative process of cross validation.

CONCLUSIONS

We developed a simple and robust decision tree model able to provide reliable informations on the probability of persistent/metastatic DTC after surgery. These information may guide post-surgery 131I administration and select patients requiring curative rather than adjuvant 131I therapy schedules.

Surgical completeness and safety of minimally invasive thyroidectomy in patients with thyroid cancer: A network meta-analysis

BACKGROUND

To assess the surgical outcomes of various minimally invasive and remote-access surgical approaches for thyroid cancer patients.

METHODS

We collected studies from January 2020 to July 2022 in 6 databases. Pairwise and network meta-analyses were performed for outcomes and complications of 9 minimally invasive interventions (minimally invasive video-assisted, endoscopic or robotic bilateral axillo-breast approach, endoscopic or robotic postauricular, endoscopic or robot transaxillary approach, transoral endoscopic thyroidectomy vestibular approach or robotic thyroidectomy) and conventional thyroidectomy (control).

RESULTS

Multiplicity and bilaterality of cancer, lymph node metastasis, and coincidence of thyroiditis showed no significant difference between minimally invasive interventions and control. However, larger tumor size (robotic bilateral axillo-breast approach standardized mean difference -1.3989, 95% confidence interval [-2.1717 to -0.6262]), higher body mass index (robot transaxillary approach standardized mean difference -0.5350, 95% confidence interval [-0.9557 to -0.1144], robotic bilateral axillo-breast approach standardized mean difference -0.2301, 95% confidence interval [-0.4389 to -0.0214]), and frequent extrathyroidal extension (robotic bilateral axillo-breast approach standardized mean difference 0.7435, 95% confidence interval [0.5602-0.9869]) were observed in control. In surgical outcomes and adverse effects, there was no significant difference in hospitalization or retrieved lymph node number between minimally invasive interventions and control. However, longer operative time was observed in the robotic bilateral axillo-breast approach(standardized mean difference 6.5393, 95% confidence interval [5.0476-8.0309]) and transoral robotic thyroidectomy (standardized mean difference 5.4946, 95% confidence interval [2.9984-7.9907]) groups than in control. In surgical completion, the rate of low postoperative serum thyroglobulin, postoperative thyroglobulin level, and postoperative radioactive iodine ablation dose showed no significant difference between minimally invasive interventions and control.

CONCLUSION

Minimally invasive thyroidectomy did not show inferior results compared to conventional thyroidectomy despite the longer operative time. Surgeons need to prudently consider all aspects of patients to determine the proper surgical approach for thyroid cancer.

Radioactive iodine therapy: multiple faces of the same polyhedron

The incidence of differentiated thyroid carcinoma (DTC) has increased in recent decades with early stage, low risk papillary thyroid cancer (PTC) being detected and diagnosed. As a result, the psychological, financial, and clinical ramifications of overdiagnosis and excessively aggressive therapy are being increasingly recognized with many authorities calling for a re-evaluation of the traditional "one size fits all" management approaches. To address these critical issues, most thyroid cancer guidelines endorse a more risk adapted management strategy where the intensity of therapy and follow up is matched to the anticipated risk of recurrence and death from DTC for each patient. This "less is more" strategy provides for a minimalistic management approach for properly selected patients with low-risk DTC. This has re-kindled the long-standing debate regarding the routine use of radioactive iodine therapy (RIT) in DTC. Although recent guidelines have moved toward a more selective use of RIT, particular in patients with low-intermediate risk DTC, the proper selection of patients, the expected benefit, and the potential risks continue to be a source of ongoing controversy and debate. In this manuscript, we will review the wide range of clinical, imaging, medical team, and patient factors that must be considered when evaluating individual patients for RIT. Through a review of the current literature evaluating the potential benefits and risks of RIT, we will present a risk adapted approach to proper patient selection for RIT which emphasizes peri-operative risk stratification as the primary tool that clinicians should use to guide initial RIT management recommendations.

Comparing surgical thoroughness and recurrence in thyroid cancer patients across race/ethnicity

BACKGROUND

For patients with differentiated thyroid cancer who will receive postoperative radioactive iodine, thyroid remnant uptake can be calculated and may point to the thoroughness of the surgical resection. In the United States, outcome disparities exist among ethnic/racial minorities with differentiated thyroid cancer. Data about surgical thoroughness and recurrence rates across races/ethnicities do not exist. This study compared the amount of thyroid remnant uptake and cancer recurrence rates across race/ethnicity.

METHODS

This was a retrospective analysis of adult patients with differentiated thyroid cancer who had postoperative radioactive iodine in 2017 and 2018 and were followed to 2020. We collected thyroid bed remnant uptake from postoperative radioactive iodine scans and analyzed it as a ratio of percent of uptake to dose of radioactive iodine received to control for varying radioactive iodine doses. Thyroid remnant, uptake to dose of radioactive iodine received, and recurrence were evaluated across race/ethnicity.

RESULTS

Of 218 patients: 61% were White, 21% Black, 11% Asian, and 7% Hispanic; 72% were female. Seventy-one percent of patients had their surgery done by a high-volume surgeon, although volume data were not available for all. In White, Black, Asian, and Hispanic patients, median uptake was 0.68%, 0.44%, 1.5%, and 0.8%, respectively (P = .13). We did not observe differences in median uptake to dose of radioactive iodine received across groups (P = .41). Recurrence rate was 17.0% among White patients, 16.7% among Black patients, 17.6% among Asian patients, and 16.7% among Hispanic patients (P = 1.00).

CONCLUSION

We did not observe differences across race/ethnicity in surgical thoroughness or rate of recurrence. These findings suggest that disparities may be mitigated when ethnic/racial minorities have similar access to quality surgical care.

Surgical outcomes of different approaches in robotic assisted thyroidectomy for thyroid cancer: A systematic review and Bayesian network meta-analysis

BACKGROUND

The aim of the study was to assess the feasibility, safety, and potential benefits of four approaches of robotic assisted thyroidectomy (RT). The approaches mentioned above are also compared with traditional open thyroidectomy (OPEN).

MATERIALS AND METHODS

Medline, Embase, Cochrane library (CENTRAL) and Web of Science databases were searched up to 13th Dec 2019. Data of surgical outcomes and complications were extracted to conduct the statistical analyses.

RESULTS

A total of 30 studies with 6622 patients were included. Ten were prospective study and 1 declared prospective randomized comparative study. The number of retrieved lymph nodes (LNs) in central compartment were similar between gasless transaxillary approach (GAA), bilateral axillo-breast approach (BABA) and transoral approach (OA). OPEN retrieved more LNs than BABA and OA. More metastatic LNs were seen in GAA and BABA than OA, as was for OPEN. The operation time was significantly shorter in GAA and gasless unilateral transaxillary approach (GUAA) than BABA and OA, while shortest for OPEN. Lower incidence of transient hypoparathyroidism was found in BABA than OPEN. No significant difference was observed in other indexes.

CONCLUSIONS

BABA, GAA, GUAA and OA in RT appear to be feasible and safe for patients with thyroid cancer with unique benefits. Surgical outcomes of different approaches were not identical for operation time, cosmetic effects, central neck dissection. Surgeons would consider more about patients' will.

Postablative 131I SPECT/CT Is Much More Sensitive Than Cervical Ultrasonography for the Detection of Thyroid Remnants in Patients After Total Thyroidectomy for Differentiated Thyroid Cancer

PURPOSE

Evaluation of utility of cervical ultrasound (US) for detection of thyroid remnants (ThR) in patients after thyroidectomy for differentiated thyroid cancer.

METHODS

Included were 154 consecutive patients (17-89 years, 123 female and 31 male patients), without known cancer residues or cervical lymph nodes metastases, admitted for ThR ablation with I, 14 to 20 weeks after surgery. Neck uptake of I (Tup) and thyroglobulin were determined, and location and volume of ThR detected by cervical US were recorded. On days 3 to 4 after ablation (1.7-4.6GBq, 46-124.3 mCi I), neck SPECT/CT was performed, and I uptake foci were assigned to one of the regions as described below. The anterior neck was divided into 2 compartments: superior and inferior to lower margin of thyroid cartilage, and each compartment was subdivided into middle and lateral regions (in SPECT/CT, posterolateral and anterolateral regions were also marked out). I uptake sites and ThR detected by US, if congruent with SPECT/CT, were counted and analyzed.

RESULTS

In total, 341 I uptake foci were found in 150 patients (97.4%) by SPECT/CT and 213 corresponding ThR in 118 patients (76.6%) by US. Ultrasound detected 30% to 46% of I uptake foci in superior lateral regions, 49% in pyramidal lobe/thyroglossal duct area (both P < 0.05), 74% to 77% in inferior lateral regions, and 22% in isthmus (both P > 0.05). Correlation between ThR volume and Tup was strong (r = 0.79), and that between ThR volume and thyroglobulin was weak (r = 0.24).

CONCLUSIONS

Ultrasound is less sensitive than I posttherapy scans for ThR detection in patients after thyroidectomy, especially for remnants located above the lower margin of thyroid cartilage.

Circulating biomarkers for the detection of tumor recurrence in the postsurgical follow-up of differentiated thyroid carcinoma

PURPOSE OF REVIEW

To discuss advances and challenges in thyroglobulin and Tg-antibody (TgAb) measurement and their impact on clinical management of differentiated thyroid carcinoma (DTC).

RECENT FINDINGS

Basal high-sensitive Tg (hsTg) measurement avoids the need for stimulation and greatly simplifies DTC patients' management. In addition, patients with undetectable hsTg after thyroid ablation are at a very low risk of recurrence and can be safely managed by periodic hsTg measurement alone. When TgAb is present, its trend over time serves as primary (surrogate) tumor marker. However, an undetectable hsTg measurement appears to indicate a complete remission of DTC even in the presence of TgAb. Finally, reliable reference values are not yet available for low-risk DTC who are treated with less than total thyroid ablation, and caution is needed before well-designed studies addressing these issues have been published.

SUMMARY

The use of hsTg assays has changed paradigms for DTC monitoring even in the presence of TgAb, and greatly reduced patients' discomfort and overall case-management costs. Reliable Tg interpretation criteria are urgently needed for patients treated with less than total thyroid ablation.

Volume, outcomes, and quality standards in thyroid surgery: an evidence-based analysis-European Society of Endocrine Surgeons (ESES) positional statement

INTRODUCTION

Continuous efforts in surgical speciality aim to improve outcome. Therefore, correlation of volume and outcome, developing subspecialization, and identification of reliable parameters to identify and measure quality in surgery gain increasing attention in the surgical community as well as in public health care systems, and by health care providers. The need to investigate these correlations in the area of endocrine surgery was identified by ESES, and thyroid surgery was chosen for this analysis of the prevalent literature with regard to outcome and volume.

MATERIALS AND METHODS

A literature search that is detailed below about correlation between volume and outcome in thyroid surgery was performed and assessed from an evidence-based perspective. Following presentation and live data discussion, a revised final positional statement was presented and consented by the ESES assembly.

RESULTS

There is a lack of prospective randomized controlled studies for all items representing quality parameters of thyroid surgery using uniform definitions. Therefore, evidence levels are low and recommendation grades are based mainly on expert and peer evaluation of the prevalent data.

CONCLUSION

In thyroid surgery a volume and outcome relationship exists with respect to the prevalence of complications. Besides volume, cumulative experience is expected to improve outcomes. In accordance with global data, a case load of < 25 thyroidectomies per surgeon per year appears to identify a low-volume surgeon, while > 50 thyroidectomies per surgeon per year identify a high-volume surgeon. A center with a case load of > 100 thyroidectomies per year is considered high-volume. Thyroid cancer and autoimmune thyroid disease predict an increased risk of surgical morbidity and should be operated by high-volume surgeons. Oncological results of thyroid cancer surgery are significantly better when performed by high-volume surgeons.

Contemporary considerations in adjuvant radioiodine treatment of adults with differentiated thyroid cancer

Differentiated thyroid cancer (DTC) is the most common endocrine malignancy with a growing incidence worldwide. The initial conventional management is surgery, followed by consideration of ¹³¹ I treatment that includes three options. These are termed remnant ablation (targeting benign thyroid remnant), adjuvant (targeting presumed microscopic DTC) and known disease (targeting macroscopic DTC) treatments. Some experts mostly rely on clinicopathologic assessment for recurrence risk to select patients for the ¹³¹ I treatment. Others, in addition, apply radioiodine imaging to guide their treatment planning, termed theranostics (aka theragnostics or radiotheragnostics). In patients with low-risk DTC, remnant ablation rather than adjuvant treatment is generally recommended and, in this setting, the ATA recommends a low ¹³¹ I activity. ¹³¹ I adjuvant treatment is universally recommended in patients with high-risk DTC (a primary tumor of any size with gross extrathyroidal extension) and is generally recommended in intermediate-risk DTC (primary tumor >4 cm in diameter, locoregional metastases, microscopic extrathyroidal extension, aggressive histology or vascular invasion). The optimal amount of ¹³¹ I activity for adjuvant treatment is controversial, but experts reached a consensus that the ¹³¹ I activity should be greater than that for remnant ablation. The main obstacles to establishing timely evidence through randomized clinical trials for ¹³¹ I therapy include years-to-decades delay in recurrence and low disease-specific mortality. This mini-review is intended to update oncologists on the most recent clinical, pathologic, laboratory and imaging variables, as well as on the current ¹³¹ I therapy-related definitions and management paradigms, which should optimally equip them for individualized patient guidance and treatment.

Postoperative thyroid remnants for differentiated thyroid cancer may not affect the outcome of high-dose radioiodine therapy

OBJECTIVES

This study aims to provide a way to estimate the volume of the thyroid remnant and determine its relationship with the outcome of radioiodine (RAI) therapy in depth.

MATERIALS AND METHODS

A retrospective analysis was performed on patients who underwent initial RAI therapy between January 2010 and January 2016. The patients were divided into five groups based on the thyroid remnant estimated by post-therapy whole-body scan(post-Rx WBS), thyroid scintigraphy and ultrasonography. The relationship between the volume of thyroid remnant and the outcome of RAI therapy were evaluated by univariate analysis and multivariate analysis.

RESULTS

Of 703 patients, the majority could be found different size of thyroid remnants using the three imaging methods, and only few patients(2.1%) could reach no thyroid remnant. There was no association between the volume of thyroid remnant and the outcome of RAI therapy in univariate analysis (χ₂ = 1.633, P = 0.652) and multivariate analysis (P > 0.05). In the subgroup of patients with high-risk factors, there was still no significant difference (intermediate risk subgroup: P = 0.338 vs high risk subgroup: P = 0.263).

CONCLUSION

Different sizes of thyroid remnants were left after surgery. However, in high radioiodine activity, the volume of thyroid remnants may not affect the outcome of RAI therapy even in patients with some high-risk factors, so the high radioiodine activities may resolve the the problem caused by thyroid remnants in some cases.

99mTc-Pertechnetate Scintigraphy Predicts Successful Postoperative Ablation in Differentiated Thyroid Carcinoma Patients Treated with Low Radioiodine Activities

BACKGROUND

Postoperative routine radioiodine (RAI) treatment is currently debated for patients with low-risk differentiated thyroid carcinoma (DTC) patients. If performed, a low ¹³¹I activity (i.e., 1 to 2 GBq) is recommended with the aim to ablate thyroid remnant and facilitate subsequent follow-up by thyroglobulin measurement. The purpose of this study was to evaluate the relationship between postsurgical technetium-99m (^99mTc)-pertechnetate scintigraphy and the rate of successful remnant ablation after low activity radioiodine ablation in patients with DTC.

METHODS

Enrolled were 193 patients with low risk DTC who underwent total thyroidectomy and RAI ablation with a fixed 1.1 GBq activity of ¹³¹I. ^99mTc-pertechnetate scans were done and thyrotropin stimulated thyroglobulin (sTg) levels measured just before ablation. Ablation effectiveness was assessed 6 to 12 months later by sTg measurement, neck ultrasound and diagnostic whole body scan.

RESULTS

A negative ^99mTc-perthecnetate scans was the best predictor of successful ablation (P<0.001) followed by preablative sTg levels <0.8 ng/mL (P=0.008) and ^99mTc-pertechnetate uptake rate values <0.9% (P=0.065). Neither sex nor age of the patient at the time of ablation or tumor histology and size showed a significant association with the rate of successful ablation.

CONCLUSION

The ^99mTc-pertechnetate scintigraphy is a simple and feasible tool to predict effectiveness of low activity ¹³¹I thyroid to ablate thyroid remnants in patients with DTC.

Routine Intraoperative Neuromonitoring of the Recurrent Laryngeal Nerve to Facilitate Complete Resection and Ensure Safety in Thyroid Cancer Surgery

Routine use of intraoperative neuromonitoring (IONM) in thyroid cancer surgery is controversial. We aimed to investigate whether it improves the completeness of thyroidectomy and ensures safety. This retrospective study included 380 thyroid cancer patients who underwent thyroidectomy, by one surgeon, between July 2006 and November 2015. Patients were grouped according to the surgeon's adaptation of IONM, as follows: none (period 1; n = 92), early (period 2; n = 141), and late (period 3; n = 147). The operative time and rates of vocal cord palsy were determined. Surgical completeness was assessed by technetium-99m imaging of the thyroid remnant and serum thyroglobulin measurement before ablation. The rate of recurrent laryngeal nerve (RLN) palsy showed a decreasing trend over time. No permanent RLN palsies occurred in nerves not invaded by tumor after routine IONM was introduced. Technetium-99m uptake (periods 1–3, 0.62 vs 0.32 vs 0.20; P < 0.01) and thyroglobulin levels (periods 1 and 2, 37.93 vs 8.98 ng/mL, respectively; P = 0.034; period 3, 9.10 ng/mL) progressively decreased. The mean thyroglobulin level dropped significantly after introduction of routine IONM. We conclude that routine IONM during thyroid cancer surgery improves surgical completeness and might prevent permanent RLN palsy over time.

Star-Shaped Intense Uptake of ¹³¹I on Whole Body Scans Can Reflect Good Therapeutic Effects of Low-Dose Radioactive Iodine Treatment of 1.1 GBq

BACKGROUND

After initial radioactive iodine (RAI) treatment in differentiated thyroid cancer patients, we sometimes observe a star-shaped region of intense uptake of ¹³¹I on whole body scans (WBSs), called a 'star artifact.' We evaluated the clinical implications of star artifacts on the success rate of remnant ablation and long-term prognosis.

METHODS

Total 636 patients who received ¹³¹I dose of 1.1 GBq for the initial RAI therapy and who did not show distant metastasis at the time of diagnosis were retrospectively evaluated. A negative second WBS was used for evaluating the ablation efficacy of the RAI therapy. Among them, 235 patients (36.9%) showed a star artifact on their first WBS.

RESULTS

In patients with first stimulated thyroglobulin (sTg) levels ≤2 ng/mL, patients with star artifacts had a higher rate of negative second WBS compared with those without star artifacts (77.8% vs. 63.9%, P=0.044), and showed significantly higher recurrence-free survival (P=0.043) during the median 8.0 years (range, 1.0 to 10.0) of follow-up. The 5- and 10-year recurrence rates (5YRR, 10YRR) were also significantly lower in patients with star artifacts compared with those without (0% vs. 4.9%, respectively, P=0.006 for 5YRR; 0% vs. 6.4%, respectively, P=0.005 for 10YRR). However, ablation success rate or recurrence-free survival was not different among patients whose first sTg levels >2 ng/mL regardless of star artifacts.

CONCLUSION

Therefore, star artifacts at initial RAI therapy imply a good ablation efficacy or a favorable long-term prognosis in patients with sTg levels ≤2 ng/mL.

Use of radioiodine-131 scan to measure influence of surgical discipline, practice, and volume on residual thyroid tissue after total thyroidectomy for differentiated thyroid carcinoma

BACKGROUND

Our study's purpose is to determine the influence of surgical discipline, surgeon site, and volume on remnant thyroid tissue visualized on radioactive iodine-131 (I-131) scans after total thyroidectomy and I-131 ablation in patients with well-differentiated thyroid carcinomas.

METHODS

We retrospectively reviewed all cases of patients who received I-131 therapeutic ablation and postablation radioactive I-131 scans at our center after thyroidectomy to calculate the fraction of administered dose multiplied by 1000 (UDR1000).

RESULTS

The remnant thyroid tissue (ie, the UDR1000), between academic and community surgeons was 0.471 (±0.705) and 1.190 (±2.487), respectively (P = .001). The UDR1000 between otolaryngology-head and neck surgery and general surgery was 0.654 (±1.575) and 1.043 (±1.625), respectively (P = .159). The UDR1000 partitioned by patient frequencies of <10, 10 to 19, and ≥20 patients yielded 1.255 (±2.554), 0.926 (±2.084), and 0.467 (±0.721), respectively (P = .003).

CONCLUSION

Our study found statistically significant differences in residual thyroid tissue visualized on radioactive I-131 scans based on surgeon parameters.

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.

Quality indicators for thyroid cancer surgery: current perspective

INTRODUCTION

While the disease specific mortality of differentiated thyroid cancer has remained low with current treatments, its incidence has been steadily rising over the past several decades, and cancer related recurrence and morbidity have remained a significant problem. Quality indicators currently employed are relevant to the surgical intervention, but do not necessarily reflect oncological outcomes. Therefore, thyroid cancer specific surgical quality indicators, that offer insight into risk of cancer related morbidity and mortality are needed.

AREAS COVERED

This review aims to discuss the role of measuring quality in thyroid surgical oncology and carry out a comprehensive review of potential quality indicators for thyroid cancer operations. The three quality indicators reviewed here are the postoperative radioactive iodine update by remnant thyroid tissue, the proportion of resected lymph nodes with evidence of metastases, and the post-operative serum thyroglobulin level. Expert commentary: Together, these quality indicators may be utilized to guide improvement of the quality of surgical care for this unique patient population. A critical future step in establishing the role of quality indicators for thyroid cancer surgery is the determination of cutoff values of each indicator in an evidence-based manner.

Value-based healthcare: implications for thyroid cancer

Today's delivery of care to thyroid cancer patients is complex, and costly, with uneven outcomes that can be improved. The incidence of thyroid cancer is rising and requires coordinated, multidisciplinary care with high volume centers that is not always available in our current fragmented healthcare system. To address the needs of patients, providers and payers, we believe that thyroid cancer care needs to be reexamined from the perspective of value for the patient, which is defined as the outcomes that matter to patients relative to the cost of delivering them. This paper provides recommendations based on the key principles of the value-based approach to transform the delivery of thyroid cancer care.

Thyroid Remnant Estimation by Diagnostic Dose (131)I Scintigraphy or (99m)TcO4(-) Scintigraphy after Thyroidectomy: A Comparison with Therapeutic Dose (131)I Imaging

In this clinical study, we have compared routine diagnostic dose ¹³¹I scan and ^99mTcO₄⁻ thyroid scintigraphy with therapeutic dose ¹³¹I imaging for accurate thyroid remnant estimation after total thyroidectomy. We conducted a retrospective review of the patients undergoing total thyroidectomy for differentiated thyroid carcinoma (DTC) and subsequently receiving radioactive iodine (RAI) treatment to ablate remnant thyroid tissue. All patients had therapeutic dose RAI whole body scan, which was compared with that of diagnostic dose RAI, ^99mTcO₄⁻ thyroid scan, and ultrasound examination. We concluded that therapeutic dose RAI scan reveals some extent thyroid remnant in all DTC patients following total thyroidectomy. Diagnostic RAI scan is much superior to ultrasound and ^99mTcO₄⁻ thyroid scan for the postoperative estimation of thyroid remnant. Ultrasound and ^99mTcO₄⁻ thyroid scan provide little information for thyroid remnant estimation and, therefore, would not replace diagnostic RAI scan.

Robotic Thyroidectomy Versus Nonrobotic Approaches: A Meta-Analysis Examining Surgical Outcomes

Background Robotic surgery has been recently used as a novel tool for remote access thyroid surgery. We performed a meta-analysis of the current literature to examine the safety and oncological efficacy of robotic surgery compared to endoscopic and conventional approaches for different thyroid procedures. Methods A systematic search of the online data bases was done using the following (MeSH) terms "robotic surgery," "robotic thyroidectomy," "robot-assisted thyroidectomy," and "robot-assisted thyroid surgery." Outcomes measured included total operative time, length of hospital stay, postoperative thyroglobulin levels, and postoperative complications. Statistical differences were analyzed between groups through the standard means and/or relative risk by using STATA analytical software. Results In this study, 144 articles were identified; of which 18 of them met our inclusion criteria, totaling 4878 patients. Robotic approach was associated with longer total operative time (mean difference of 43.5 minutes) when compared to the conventional cervical approach (95% CI = 20.9-66.2; P < .001). Robotic approach was also found to have a similar risk of total postoperative complications when compared to the conventional and endoscopic approaches. Conclusion Robotic thyroid surgery is as safe, feasible and provides similar periperative complications and oncological outcomes when compared to both, conventional cervical and endoscopic approaches. However, robotic thyroid surgery is associated with longer operative time when compared to the conventional open approach.

[Consensus statement for accreditation of multidisciplinary thyroid cancer units]

Thyroid cancer is the leading endocrine system tumor. Great advances have recently been made in understanding of the origin of these tumors and the molecular biology that makes them grow and proliferate, which have been associated to improvements in diagnostic procedures and increased availability of effective local and systemic treatments. All of the above makes thyroid cancer a paradigm of how different specialties should work together to achieve the greatest benefit for the patients. Coordination of all the procedures and patient flows should continue throughout diagnosis, treatment, and follow-up, and is essential for further optimization of resources and time. This manuscript was prepared at the request of the Working Group on Thyroid Cancer of the Spanish Society of Endocrinology and Nutrition, and is aimed to provide a consensus document on the definition, composition, requirements, structure, and operation of a multidisciplinary team for the comprehensive care of patients with thyroid cancer. For this purpose, we have included contributions by several professionals from different specialties with experience in thyroid cancer treatment at centers where multidisciplinary teams have been working for years, with the aim of developing a practical consensus applicable in clinical practice.

Novel thyroidectomy difficulty scale correlates with operative times

BACKGROUND

The aim of this study was to evaluate a new thyroidectomy difficulty scale (TDS) for its inter-rater agreement, correspondence with operative times, and correlation with complications.

METHODS

We developed a four item, 20-point TDS. Following cases where two board-certified surgeons participated, each surgeon completed a TDS, blinded to the other's responses. Paired sets of TDS scores were compared. The relationship between operative time and TDS scores was analyzed with linear regression. Multiple regression evaluated the association of TDS scores and other clinical data with operative times.

RESULTS

A total of 119 patients were scored using TDS. In this cohort, 22.7% suffered from hyperthyroidism, 37.8% experienced compressive symptoms, and 58.8% had cancer. The median total TDS score was 8, and both surgeons' total scores exhibited a high degree of correlation. Overall, 87.4% of the two raters' total scores were within one point of each other. Patients with hyperthyroidism received higher median scores than euthyroid patients (10 vs. 8, p < 0.01). Similarly, patients who suffered a complication had higher scores than those without complications (10 vs. 8, p = 0.04). TDS scores demonstrated a linear relation with operative times (R2 = 0.36, p < 0.01). Cases with a score of ≥14 took 41.0% longer compared to cases with scores of ≤5 (p < 0.01). In the multiple regression analysis, TDS scores independently predicted the operative time (p < 0.01).

CONCLUSION

The TDS is an accurate tool whose scores correlate with more difficult thyroidectomies as measured by complications and operative times.

Thyroglobulin antibody resolution after total thyroidectomy for cancer

BACKGROUND

Thyroglobulin antibodies (TgAb) are produced by 10%-25% of thyroid cancer patients and interfere with thyroglobulin measurement, a marker of residual or recurrent cancer after surgery. Our purpose was to describe the TgAb resolution time course and the significance of persistent antibody elevation after thyroidectomy.

METHODS

A database of 247 consecutive patients with TgAb measured preoperatively who underwent thyroidectomy for differentiated thyroid cancer between January 2007 and May 2013 was reviewed. Patients were stratified by TgAb status (positive or negative) and recurrence (defined as biopsy proven disease or unplanned second surgery). Survival and regression analysis was used to determine TgAb resolution time course. Log-rank was used to determine an association between persistent antibody elevation and recurrence.

RESULTS

Of 247 patients (77% women, 23% men; mean 45.7 ± 1.0 y) with TgAb measured preoperatively, 34 (14%) were TgAb+ (≥20 IU/mL; mean 298.1 ± 99.2 IU/mL). Median time to TgAb resolution was 11.0 ± 2.3 mo, and the majority resolved by 32.4 mo. Regression analysis of patients with antibody resolution yielded an average decline of -11% IU/mL per month ± 2.2%. Disease-free survival was equivalent between TgAb-positive and TgAb-negative groups (P = 0.8). In 9 of 34 patients, antibodies had not resolved at the last follow-up and imaging could not identify recurrent disease.

CONCLUSIONS

TgAb are common in patients with thyroid cancer but resolve after treatment at approximately -11% IU/mL per month from preoperative levels with median resolution at 11.0 mo. Persistently elevated levels after thyroidectomy were not associated with disease recurrence in our series.

The evolving use of radioiodine therapy in differentiated thyroid cancer

The incidence of differentiated thyroid cancer has increased worldwide over the last three decades, but thyroid cancer-related mortality remains stable. Until recently, the standard treatment for most thyroid cancers has been near-total thyroidectomy followed by radioiodine remnant ablation. Observational data support lower recurrence rates and improved survival after radioiodine ablation in patients with high-risk cancers; however, a similar benefit has not been established for all patients with thyroid cancer. Risk stratification should be used to identify patients who are likely to benefit from radioiodine ablation and guide therapeutic decisions. For most patients who need radioiodine remnant ablation, preparation for therapy with recombinant human thyroid-stimulating hormone stimulation is as effective as thyroid hormone withdrawal. Lower therapeutic doses of radioiodine are recommended for the majority of thyroid remnant ablations. Higher doses are reserved for advanced disease at initial diagnosis, local recurrences that cannot be treated with surgery alone, and distant metastatic disease.

Surgeon volume and adequacy of thyroidectomy for differentiated thyroid cancer

INTRODUCTION

We aimed to determine influence of surgeon volume on (1) frequency of appropriate initial surgery for differentiated thyroid cancer (DTC) and (2) completeness of resection.

METHODS

We reviewed all initial thyroidectomies (Tx; lobectomy and total) performed in a health system during 2011; surgeons were grouped by number of Tx cases per year. For patients with histologic DTC ≥ 1 cm, surgeon volume was correlated with initial extent of the operation, and markers of complete resection including uptake on I(123) prescan, thyrotropin-stimulated thyroglobulin levels, and I(131) dose administered.

RESULTS

Of 1,249 patients who underwent Tx by 42 surgeons, 29% had DTC ≥ 1 cm without distant metastasis. At a threshold of ≥ 30 Tx per year, surgeons were more likely to perform initial total Tx for DTC ≥ 1 cm (P = .01), and initial resection was more complete as measured by all 3 quantitative markers. For patients with advanced stage disease, a threshold of ≥ 50 Tx per year was needed before observing improvements in I(123) uptake (P = .004).

CONCLUSION

Surgeons who perform ≥ 30 Tx a year are more likely to undertake the appropriate initial operation and have more complete initial resection for DTC patients. Surgeon volume is an essential consideration in optimizing outcomes for DTC patients, and even higher thresholds (≥ 50 Tx/year) may be necessary for patients with advanced disease.

[Total thyroidectomy with lymph node dissection of the central compartment for node-positive, capsular invasive papillary thyroid cancer: video contribution]

The aim of radical oncological surgery for nodal metastasized papillary thyroid cancer is, as for other oncological interventions in visceral surgery, the anatomy-related implementation of the concept of en bloc (no touch) resection of the organ bearing the primary tumor together with the first lymph node station, while the structures of the aerodigestive tract, the recurrent laryngeal nerves and parathyroid glands are preserved. The surgical technique is demonstrated in detail with the help of a video of the operation and which is available on-line, the advantages and disadvantages of the technique are discussed.

Measuring Quality in Thyroid Cancer Surgery

Many of the surgical quality measures currently in use are not disease specific. For thyroid cancer, mortality and even recurrence are difficult to measure since mortality is rare and recurrence can take decades to occur. Therefore, there is a critical need for quality indicators in thyroid cancer surgery that are easily measured and disease specific. Here we will review recent research on two potential quality indicators in thyroid cancer surgery. The uptake percentage on postoperative radioactive iodine scans indicates the completeness of resection. Another measure, the lymph node ratio, is the proportion of metastatic nodes to the total number of nodes dissected. This serves as a more global measure of quality since it indicates not only the completeness of lymph node dissection but also the preoperative lymph node evaluation and decision-making. Together, these two quality measures offer a more accurate, disease-specific oncologic indicator of quality that can help guide quality assurance and improvement.

Radioactive iodine remnant uptake after completion thyroidectomy: not such a complete cancer operation

BACKGROUND

Given limitations in preoperative diagnostics, thyroid lobectomy followed by completion thyroidectomy (CT) for differentiated thyroid cancer (DTC) may be required. It is unclear whether resection quality by CT differs from that by total thyroidectomy (TT). Additional surgeon or patient factors may also influence the "completeness" of resection. This study evaluated how CT and surgeon volume influence the adequacy of resection as measured by radioactive iodine (RAI) remnant uptake.

METHODS

A retrospective review of a prospectively collected thyroid database was queried for patients treated for DTC with TT or CT followed by RAI ablation. CT patients were matched 1:2 by age, sex, and tumor size to TT patients. Surgeon volume, time to completion, and continuity of surgeon care were reviewed.

RESULTS

Over 18 years, 45 patients with DTC had CT and RAI. Mean age was 48 ± 2 years, and 76 % were female, with a tumor size of 2.7 ± 0.3 cm. CT had higher remnant uptake than TT (0.07 vs. 0.04 %; p = 0.04). CT performed by a high-volume surgeon had much lower remnant uptakes (0.06 vs. 0.22 %; p = 0.04). Remnant uptake followed a stepwise decrease with involvement of a high-volume surgeon for part or all of the surgical management (p = 0.11). Multiple regression analysis found CT (p = 0.02) and surgeon volume (p = 0.04) to significantly influence uptake after controlling for other factors.

CONCLUSIONS

Single-stage TT provides a better resection based on smaller thyroid remnant uptakes than CT for patients with thyroid cancer. If a staged operation for cancer is necessary, surgeon volume may affect the completeness of resection.

Markedly elevated thyroglobulin levels in the preoperative thyroidectomy patient correlates with metastatic burden

BACKGROUND

Thyroglobulin (Tg) is a marker of tumor recurrence during thyroid cancer follow-up. While helpful in the postoperative setting, the clinical significance of preoperative Tg measurements remains unclear. The aim of the study was to determine if preoperative Tg levels are indicative of underlying malignancy or burden of metastatic disease.

METHODS

A retrospective review of a prospectively collected database at an academic medical center of all thyroidectomy patients with a measured preoperative Tg level was conducted. Patients were grouped by Tg level into quartiles for initial univariate analysis, followed by multivariable analysis of variance.

RESULTS

Between 2007 and 2012, 611 patients met criteria. Quartile breakdown was as follows: ≤19 ng/mL, 19.1-54 ng/mL, 54.1-151 ng/mL, and >151 ng/mL. Patients' age and gender were equivalent. Hashimoto's thyroiditis was most common in the lowest Tg group (24% versus 11%-12%, P < 0.01). While cancer was more common in the low Tg, metastatic disease was most common in the high Tg group. Specimen weight increased with increasing Tg levels (P < 0.01). Body mass index, gland weight, cancer, and Hashimoto's and metastatic disease were entered into a multivariable analysis. Only gland weight and metastatic disease correlated with Tg levels (both P < 0.001). All patients with Tg > 5000 ng/mL had metastatic disease (n = 6).

CONCLUSIONS

Although preoperative Tg levels are not associated with a diagnosis of cancer, they are associated with the presence of metastatic disease. All patients with a Tg > 5000 ng/mL had significant disease burden. In patients with concern for metastatic disease, preoperative serum Tg may be a useful marker to aid decision making.