Prognostic value of post-thyroidectomy thyroglobulin levels in patients with differentiated thyroid cancer

Predictors of recurrence after total thyroidectomy in 1,611 patients with papillary thyroid carcinoma: postoperative stimulated serum thyroglobulin and ATA initial and dynamic risk assessment

Objective

Despite a favorable prognosis, some patients with papillary thyroid carcinoma (PTC) develop recurrence. The objective of this study was to examine the impact of the combination of initial American Thyroid Association (ATA) risk stratification with serum level of postoperative stimulated thyroglobulin (s-Tg) in predicting recurrence in patients with PTC and compare the results with an assessment of response to initial therapy (dynamic risk stratification).

Subjects and methods

We retrospectively analyzed 1,611 patients who had undergone total thyroidectomy for PTC, followed in most cases (87.3%) by radioactive iodine (RAI) administration. Clinicopathological features and s-Tg levels obtained 3 months postoperatively were evaluated. The patients were stratified according to ATA risk categories. Nonstimulated thyroglobulin levels and imaging studies obtained during the first year of follow-up were used to restage the patients based on response to initial therapy.

Results

After a mean follow-up of 61.5 months (range 12-246 months), tumor recurrence was diagnosed in 99 (6.1%) patients. According to ATA risk, recurrence was identified in 2.3% of the low-risk, 9% of the intermediate-risk, and 25% of the high-risk patients (p < 0.001). Using a receiver operating characteristic curve approach, a postoperative s-Tg level of 10 ng/mL emerged as the ideal cutoff value, with positive and negative predictive values of 24% and 97.8%, respectively (p < 0.001). Patients with low to intermediate ATA risk with postoperative s-Tg levels < 10 ng/mL and excellent response to treatment had a very low recurrence rate (<0.8%). In contrast, higher recurrence rates were observed in intermediate-riskto high-risk patients with postoperative s-Tg > 10 ng/mL and indeterminate response (25%) and in those with incomplete response regardless of ATA category or postoperative s-Tg value (38.5-87.5%). Using proportion of variance explained (PVE), the predicted recurrence using the ATA initial risk assessment alone was 12.7% and increased to 29.9% when postoperative s-Tg was added to the logistic regression model and 49.1% with dynamic risk stratification.

Conclusion

The combination of ATA staging system and postoperative s-Tg can better predict the risk of PTC recurrence. Initial risk estimates can be refined based ondynamic risk assessment following response to therapy, thus providing a useful guide for follow-up recommendations.

Early Post-operative Stimulated Serum Thyroglobulin: Role in Preventing Unnecessary Radioactive Iodine Treatment in Low to Intermediate Risk Papillary Thyroid Cancer

AIM

The aims of the study are to evaluate the predictive value of early post-operative stimulated thyroglobulin (sTg) analysis on the recurrence risk, and to define a cut-off value that is related to recurrence risk in low to intermediate risk papillary thyroid cancer (PTC).

METHODS

This retrospective cohort study included individuals who were diagnosed with PTC aged 18 years or older and had been operated by experienced surgeons of a tertiary university hospital between the years 2011 and 2021. The American Thyroid Association thyroid cancer guidelines version 2015 was used as the risk stratification system. Early sTg measurement obtained at 3-4 weeks after surgery when TSH >30 µIU/mL. Data was collected from the hospital database. A total of 328 patients who had post-operative early sTg values with negative anti-Tg antibodies were included.

RESULTS

The median age was 44 years. Of the 328 patients, 223 (68%) were women. The median tumor diameter was 11 mm. One hundred ninety-one patients (58.2%) had low risk and 137 (41.8%) had intermediate risk for recurrent disease. Of the 328 patients, 4.0% had recurrent disease. In multivariate Cox regression, post-operative early sTg value [OR: 1.070 (1.038-1.116), P = .000], and the pre-operative malign cytology [OR: 1.483 (1.080-2.245), P = .042] were independent risk factors for recurrence. On the ROC curve analysis, the cut-off value of early sTg was 4.1 ng/mL for those with recurrent disease.

CONCLUSION

This study demonstrated that early sTg could predict recurrent disease in patients with low to intermediate risk PTC. A cut-off of 4.1 ng/mL was identified with a high negative predictive value.

A Comparison of Completeness and Complication of Total Thyroidectomy with or Without Neuromonitoring

Objectives

Total Thyroidectomy (TT) in true sense is not total as evidenced by remnant uptake in radio-iodine scans and serum thyroglobulin. The aim of this study is to assess the completeness of TT, operating time and recurrent laryngeal nerve injury with and without neuro-monitoring (IONM).

Methods

Cross sectional analytical study using retrospective data of patients undergoing total thyroidectomy for benign and malignant goiters. Surgeries performed by single surgeon. Patients undergoing TT (2015-22) were grouped into Group A (n = 400) and Group B (n = 400) based on use of IONM. Subgroup of patients (Group A1&B1) who had differentiated thyroid cancer were compared for completeness of thyroidectomy with DxWBS and serum thyroglobulin (TG). Group A and B were compared for operating time and incidence of RLN palsy.

Results

Of the 800 RLN at risk transient RLN palsy was lower with IONM (p = 0.048). Mean operating time was significantly higher in Group-B(p = 0.0038). Subgroup A1 showed lower radio-active iodine uptake percentage, higher number of patients with negative scan, TG of < 1ng/mL indicating better completeness of TT.

Conclusion

Our study shows better completeness of thyroidectomy, lower incidence of transient RLN palsy and shorter operating time with IONM.

Analysis of factors influencing the clinical outcome after surgery and 131I therapy in patients with moderate-risk thyroid papillary carcinoma

PURPOSE

Generally, the prognosis for papillary thyroid cancer (PTC) is favorable. However, the moderate risk involved warrants further evaluation. Hence, we investigated the clinical outcomes in patients with moderate-risk PTC following surgery and the first ¹³¹I therapy, as well as the relevant factors that influence the therapeutic efficacy.

METHODS

Retrospective analyses of 175 patients with medium-risk PTC who visited the Second Affiliated Hospital of Chongqing Medical University from September 2017 to April 2019 were conducted. In according with the 2015 American Thyroid Association (ATA) guideline treatment response evaluation system, the patients were categorized into the following groups: excellent response (ER), indeterminate response (IDR), biochemical incomplete response (BIR), and structurally incomplete response (SIR), of which IDR, BIR, and SIR were collectively referred to as the NER group. To compare the general clinical features between the 2 groups of patients, 2 independent samples t-tests, χ² test, and Mann-Whitney U-test were performed, followed by multivariate logistic regression analyses. With reference to the receiver operating characteristic (ROC) curve, the predicted value of ps-Tg to ER was evaluated, and the best cut-off value was determined. The subgroups with BRAF^V600E test results were analyzed by χ2 test only.

RESULTS

The treatment responses of 123 patients were ER, while those of 52 patients were NER. The differences in the maximum tumor diameter (U = 2495.50), the amount of metastatic lymph nodes (U = 2313.50), the size of metastatic lymph node (U = 2113.50), the metastatic lymph node ratio (U = 2111.50), metastatic lymph node location (χ² = 9.20), and ps-Tg level (U = 1011.00) were statistically significant. Multivariate regression analysis revealed that ps-Tg (OR = 1.209, 95% CI: 1.120-1.305) was an independent variable affecting ER. The cut-off value of ps-Tg for predicting ER was 6.915 ug/L, while its sensitivity and specificity were 69.2% and 89.4%, respectively.

CONCLUSIONS

Patients with smaller tumor size, fewer lymph nodes, lower metastatic lymph node ratio, metastatic lymph nodes in the central region, smaller lymph node size, and ps-Tg <6.915 ug/L demonstrated better therapeutic effects after the initial treatment.

Preablative Stimulated Thyroglobulin and Thyroglobulin Reduction Index as Decision-Making Markers for Second Radioactive Iodine Therapy in Patients with Structural Incomplete Response

Purpose

The aim of this study was to evaluate the value of preablative stimulated thyroglobulin (presTg) and thyroglobulin reduction index (TRI) to predict the different responses to second radioactive iodine (RAI) therapy in differentiated thyroid cancer (DTC) patients with structural incomplete response (SIR).

Patients and Methods

A single-center retrospective study analyzed the different clinical outcomes after second RAI therapy in 206 patients with SIR. PresTg1 and presTg2 were measured before first and second RAI management and TRI was the reduction index of presTg1 and presTg2. Cut-off values of presTg and TRI were obtained using receiver operating characteristic analysis. The univariate logistic regression analysis was performed to confirm these parameters as prognostic factors to predict different responses to second RAI therapy.

Results

Only ATA risk stratification, the post-therapy whole-body scanning (Rx-WBS) findings, presTg1, presTg2, TRI, were different in patients with SIR. After second RAI therapy, 28.2% (58/206) of patients with SIR initially were reclassified as excellent response (ER). PresTg1 <6.6 ng/mL, presTg2 <1.2ng/mL, and TRI >74.2% were excellent indications to predict ER from non-ER after second RAI treatment. PresTg1 >14.9 ng/mL, presTg2 >1.8ng/mL and TRI <66.5% were well markers to predict poor outcome (SIR). High risk and distant metastases could still be considered as risk factors.

Conclusion

DTC patients with SIR could benefit through second RAI treatment. PresTg before each RAI therapy and TRI could be considered as effective decision-making markers for second RAI therapy and as predictive indications for clinical outcomes.

A cutoff thyroglobulin value suggestive of distant metastases in differentiated thyroid cancer patients

Serum thyroglobulin is used as part of the early postoperative assessment of differentiated thyroid cancer (DTC) since there is a clear relationship between an increased risk of recurrence and persistent disease after initial treatment and high postoperative stimulated thyroglobulin (ps-Tg) values. Thus, although ps-Tg above 10-30 ng/mL is considered an independent predictor of worse prognosis, the value that is associated with distant metastases is not defined. Thus, this was our objective. We selected 655 DTC patients from a nuclear medicine department database (Irmandade Santa Casa de Misericórdia de São Paulo, Brazil). All patients had received total thyroidectomy and radioactive iodine (RAI) therapy and had ps-Tg values higher than 10 ng/mL with negative anti-thyroglobulin antibodies. Then, we selected patients who presented post-therapy whole-body scan with pulmonary and/or bone uptake but with no mediastinum or cervical uptake. Patients with negative findings on functional imaging or any doubt on lung/bone uptake were submitted to additional exams to exclude another non-thyroid tumor. Of the 655 patients, 14.3% had pulmonary and 4.4% bone metastases. There was a significant difference in ps-Tg levels between patients with and without metastases (P<0.001). The cutoff value of ps-Tg was 117.5 ng/mL (sensitivity: 70.2%; specificity: 71.7%) for those with lung metastasis, and 150.5 ng/mL (sensitivity: 79.3%; specificity: 85%) for those with bone metastasis. The cutoff value for patients with eitherpulmonary or bone metastasis was 117.5 ng/mL (sensitivity: 70.2%; specificity: 83.7%). Our findings demonstrated that ps-Tg could predict distant metastasis in DTC patients. We identified a cutoff of 117.5 ng/mL with a high negative predictive value of 93.7%.

Efficacy of Low-Dose Radioiodine Ablation in Low- and Intermediate-Risk Differentiated Thyroid Cancer: A Retrospective Comparative Analysis

(1) Background-low-dose radioiodine ablation is an accepted strategy for the treatment of low- and intermediate-risk thyroid carcinomas, although there is no international consensus. The aim of this study is to describe the clinical experience with low-dose radioiodine ablation in patients with low- and intermediate-risk thyroid cancer compared to high-dose ablation. (2) Methods-174 patients with low- and intermediate-risk thyroid cancer, 90 treated with low-dose ablation and 84 treated with high-dose ablation, were included. The primary endpoint was response to treatment one year after ablation, defined by stimulated thyroglobulin, whole body scan and ultrasound imaging. (3) Results-an excellent response rate of 79.8% in the low-dose group and 85.7% in the high-dose group was observed (p = 0.049). Stimulated thyroglobulin at the moment of ablation (p = 0.032) and positive antithyroglobulin antibodies (p < 0.001) were independent predictive factors for nonexcellent response. Young age (p = 0.023), intermediate initial recurrence risk (p < 0.001) and low-dose ablation (p = 0.004) were independent predictive factors for recurrence. (4) Conclusion-low-dose ablation seemed to be less effective than high-dose ablation, especially in those patients with positive antithyroglobulin antibodies or higher stimulated thyroglobulin levels at the moment of ablation. Low dose was associated with higher recurrence rates, and lower age and intermediate initial recurrence risk were independent risk factors for recurrence in our sample.

Risk factors for radioactive iodine-avid metastatic lymph nodes on post I-131 ablation SPECT/CT in low- or intermediate-risk groups of papillary thyroid cancer

Objective

Post I-131 ablation single-photon emission computed tomography (SPECT)/CT can show radioactive iodine (RAI)-avid cervical metastatic lymph nodes (mLN) in differentiated thyroid cancer. This study aimed to evaluate the incidence of RAI-avid mLN on post I-131 ablation SPECT/CT and the risk factors related to metastasis among patients with papillary thyroid cancer (PTC) in the low- or intermediate-risk groups.

Study design and setting

Among 339 patients with PTC who underwent total thyroidectomy followed by I-131 ablation, 292 (228 women, 64 men) belonging to the low- or intermediate-risk groups before I-131 ablation, and with sufficient clinical follow-up data were enrolled. The risk groups were classified based on the American Thyroid Association 2015 guideline. Each patient was followed-up for at least 24 months after the ablation (median: 30 months). The clinical, pathologic, and biochemical factors of PTC were reviewed, and their relationships to RAI-avid mLN on SPECT/CT were analyzed.

Results

Of the 292 patients, 61 and 231 belonged to the low-and intermediate-risk groups, respectively. Four (6.5%) patients in the low-risk group and 31 (13.0%) patients in the intermediate-risk group had RAI-avid mLN. A high preablation TSH-stimulated serum thyroglobulin (Tg) level in the low- or intermediate-risk group predicted the presence of RAI-avid mLN (cut-off = 0.5; hazard ratio (HR): 2.96; p = 0.04). In the subgroup analysis by risk group, TSH-stimulated serum Tg only predicted RAI-avid mLN in the low-risk group (cut-off = 1.0; HR: 5.3; p = 0.03).

Conclusion

The incidence of RAI-avid mLN on postablation SPECT/CT was relatively high in both low- and intermediate-risk patients with PTC, and high preablation TSH-stimulated serum Tg level was a predictor of metastasis, especially in the low-risk group. A selective treatment approach should be considered in patients with high preablation TSH-stimulated serum Tg level.

Low-Dose Radioiodine Ablation in Patients with Low-Risk Differentiated Thyroid Cancer

AIM

Based on the response criteria of the 2015 American Thyroid Associations guidelines, our objectives were to -determine the response rate when using a low dose of -131-I GBq in patients with low-risk differentiated thyroid cancer (LRDTC) and the influence of clinical and analytical variables on the prediction of complete response.

METHODS

We performed a multicentre and longitudinal study, including patients who were operated for LRDTC and who underwent radioiodine remnant ablation with a low-dose of 131-I. All patients were assessed at 6-12 months, and their status was classified as complete (excellent response) or incomplete response (structural incomplete, biochemical incomplete or indeterminate response). Various factors including age, gender, histology, tumour focality and size, stage, time from surgery to treatment, type of thyroid-stimulating hormone (TSH) stimulation, preablation serum thyroglobulin (pTg), antiTg antibodies (pAntiTgAb) and TSH (pTSH) levels were also analysed in order to predict the complete response rate.

RESULTS

Of 108 patients, 79.6$ achieved complete response and the remaining showed incomplete response (2.9, 5.5 and 12$ due to biochemical incomplete, structural incomplete and indeterminate response respectively). Six patients received a new dose of 131-I. Tumour size and pAntiTgAb were the only factors related to therapeutic response (p = 0.03 and p < 0.01, respectively). However, pAntiTgAb was the only independent factor related to complete -response. Patients with complete response showed lower pTg than those with incomplete response (5.1 ± 12.9 vs. 11.2 ± 25 ng/mL) although without statistical significance (p = 0.14). There was no significant difference in the response rate depending on the thyrotropin stimulation methods.

CONCLUSIONS

A low dose of 131-I was sufficient for reaching a complete response at 6-12 months of follow-up in the majority of patients with LRDTC. Tumour size and pAntiTgAb variables were related to therapeutic response.

Role of Preablative Stimulated Thyroglobulin in Prediction of Nodal and Distant Metastasis on Iodine Whole-Body Scan

Background:

Preablative stimulated thyroglobulin (ps-Tg) is an important investigation in the follow-up of patients with Differentiated thyroid cancer(DTC) after surgery. Levels of ps-Tg >2–10 ng/ml have been suggested to predict metastasis to cervical and extracervical sites. There is still debate on the need for routine iodine whole-body scan (¹³¹I WBS) in the management of low-to-intermediate-risk DTC patients.

Objective:

We analyzed our data of patients with DTC who underwent total thyroidectomy to discuss the predictability of ps-Tg on metastatic disease on the ¹³¹I WBS.

Materials and Methods:

Retrospective analysis of patient records.

Results:

One hundred and seventeen patients with DTC (95 papillary thyroid cancer [71 had classic histology, 8 had tall cell variant, 16 had follicular variant] and 22 follicular thyroid cancer [18 minimally invasive, 2 hurtle cell, and 2 widely invasive cancers]) had undergone total thyroidectomy. All these patients underwent ps-Tg assessment and an ¹³¹I WBS. About 65% of them went on to have radioiodine ablation along with a posttherapy ¹³¹I WBS. We divided the cohort into four groups based on their ps-Tg levels: Group 1 (ps-Tg <1), Group 2 (ps-Tg 1–1.9), Group 3 (ps-Tg 2–5), and Group 4 (ps-Tg >5). None of the patients in Group 1, 7% of those combined in Groups 2 and 3 (2 out of 28 patients), and 26% (12 out of 47) of those in Group 4 had either cervical or extracervical metastasis. Those with extracervical metastatic disease to lungs and bones had a mean (standard deviation) ps-Tg value of 436 (130) and median of 500 ng/ml and those with cervical metastatic disease had a mean Tg value of 31 (64) and median 6.6 ng/ml.

Conclusions:

A ps-Tg value in the absence of anti-Tg antibodies <1 ng/ml reliably excludes metastatic disease in DTC, while a value >5 ng/ml has a 26% risk of having either cervical or extracervical metastasis.

The need of prophylactic central lymph node dissection is controversial in terms of postoperative thyroglobulin follow-up of patients with cN0 papillary thyroid cancer

PURPOSE

The objective of this study was to investigate whether prophylactic central lymph node dissection (pCLND) facilitates postoperative thyroglobulin (Tg) follow-up in the patients with papillary thyroid carcinoma (PTC). We also questioned whether radioactive iodine (RAI) remnant ablation provides any further advantage in this regard.

METHODS

The records of patients with low-intermediate risk PTC who underwent either only total thyroidectomy (TT) or TT in conjunction with pCLND were reviewed. Adjuvant RAI ablation was performed depending on tumor diameter, multifocality, the presence of positive lymph nodes and adverse histopathologic features. Pre-ablative and post-ablative Tg levels, post-operative complications and clinico-pathological characteristics were compared between the two groups (TT alone and TT with pCLND).

RESULTS

Among the 302 patients, TT was performed in 140 (46.4%) and TT with pCLND in 162 (53.6%). More than half of all patients in both groups had papillary microcarcinoma (58.0% and 53,1%, respectively). Postoperatively, the median preablative Tg level was higher in the TT only group than that of the TT with pCLND group (0.96 vs 0.27 ng/ml, respectively). The post-ablative Tg levels were undetectable in both groups at the last follow-up visit. Also, a subgroup of patients (19.5%) who did not receive RAI ablation all became athyroglobulinemic at one year after surgery.

CONCLUSIONS

Although performing pCLND with TT seems to have an advantage over TT alone as to achieve lower Tg levels in the early post-operative period, Tg levels become comparable following RAI ablation. On the other hand, the patients who have not been treated with adjuvant RAI ablation, also became athyroglobulinemic regardless of the surgical method.

Reappraisal of the indication for radioiodine thyroid ablation in differentiated thyroid cancer patients

Radioactive iodine therapy is administered to patients with differentiated thyroid cancer (DTC) for eradication of thyroid remnant after total thyroidectomy or, in patients with metastatic disease, for curative or palliative treatment. In past years, thyroid remnant ablation was indicated in almost every patient with a diagnosis of DTC. Nowadays, careful revision of patients' outcome has introduced the concept of risk-based selection of patients candidate to thyroid remnant ablation. The present review aims to underline the indications for thyroid remnant ablation and to address methodologies to be employed.

Risk Stratification in Differentiated Thyroid Cancer: An Ongoing Process

Thyroid cancer is an increasingly common malignancy, with a rapidly rising prevalence worldwide. The social and economic ramifications of the increase in thyroid cancer are multiple. Though mortality from thyroid cancer is low, and most patients will do well, the risk of recurrence is not insignificant, up to 30%. Therefore, it is important to accurately identify those patients who are more or less likely to be burdened by their disease over years and tailor their treatment plan accordingly. The goal of risk stratification is to do just that. The risk stratification process generally starts postoperatively with histopathologic staging, based on the AJCC/UICC staging system as well as others designed to predict mortality. These do not, however, accurately assess the risk of recurrence/persistence. Patients initially considered to be at high risk may ultimately do very well yet be burdened by frequent unnecessary monitoring. Conversely, patients initially thought to be low risk, may not respond to their initial treatment as expected and, if left unmonitored, may have higher morbidity. The concept of risk-adaptive management has been adopted, with an understanding that risk stratification for differentiated thyroid cancer is dynamic and ongoing. A multitude of variables not included in AJCC/UICC staging are used initially to classify patients as low, intermediate, or high risk for recurrence. Over the course of time, a response-to-therapy variable is incorporated, and patients essentially undergo continuous risk stratification. Additional tools such as biochemical markers, genetic mutations, and molecular markers have been added to this complex risk stratification process such that this is essentially a continuum of risk. In recent years, additional considerations have been discussed with a suggestion of pre-operative risk stratification based on certain clinical and/or biologic characteristics. With the increasing prevalence of thyroid cancer but stable mortality, this risk stratification may identify those in whom the risk of conventional surgical treatment may outweigh the benefit. This review aims to outline the process of risk stratification and highlight the important concepts that are involved and those that are continuously evolving.

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.

Clinical Outcome of Remnant Thyroid Ablation with Low Dose Radioiodine in Korean Patients with Low to Intermediate-risk Thyroid Cancer

Radioiodine activity required for remnant thyroid ablation is of great concern, to avoid unnecessary exposure to radiation and minimize adverse effects. We investigated clinical outcomes of remnant thyroid ablation with a low radioiodine activity in Korean patients with low to intermediate-risk thyroid cancer. For remnant thyroid ablation, 176 patients received radioiodine of 1.1 GBq, under a standard thyroid hormone withdrawal and a low iodine diet protocol. Serum levels of thyroid stimulating hormone stimulated thyroglobulin (off-Tg) and thyroglobulin-antibody (Tg-Ab), and a post-therapy whole body scan (RxWBS) were evaluated. Completion of remnant ablation was considered when there was no visible uptake on RxWBS and undetectable off-Tg (<1.0 ng/mL). Various factors including age, off-Tg, and histopathology were analyzed to predict ablation success rates. Of 176 patients, 68.8% (n = 121) who achieved successful remnant ablation were classified into Group A, and the remaining 55 were classified into Group B. Group A presented with significantly lower off-Tg at the first radioiodine administration (pre-ablative Tg) than those of Group B (1.2 ± 2.3 ng/mL vs. 6.2 ± 15.2 ng/mL, P = 0.027). Pre-ablative Tg was the only significant factor related with ablation success rates. Diagnostic performances of pre-ablative Tg < 10.0 ng/mL were sensitivity of 99.1%, specificity of 14.0%, positive predictive value of 71.1%, and negative predictive value of 87.5%, respectively. Single administration of low radioiodine activity could be sufficient for remnant thyroid ablation in patients with low to intermediate-risk thyroid cancer. Pre-ablative Tg with cutoff value of 10.0 ng/mL is a promising factor to predict successful remnant ablation.

Indications for the gasless transaxillary robotic approach to thyroid surgery: experience of forty-seven procedures at the american hospital of paris

BACKGROUND

Thyroid surgery is in a state of evolution from traditional open approaches to novel robotic techniques. The gasless transaxillary approach to thyroid surgery is effective in the management of thyroid cancer, and complications after robotic thyroidectomy are no higher than experienced after open or endoscopic techniques. The transaxillary robotic approach also avoids an anterior neck scar. This paper presents what the authors believe to be the largest cohort of patients reported in Europe undergoing gasless transaxillary robotic thyroid surgery, with the aim of defining the indications for this procedure.

METHODS

Forty-six patients underwent robotic thyroid surgery via the transaxillary approach and were enrolled in this study between March 2010 and September 2012. All patients were operated on by one surgeon at one clinical center. Reviewed data included patient characteristics, pathological characteristics, extent of surgery and postoperative complications. The mean follow-up time was 7.29 months.

RESULTS

Forty-six patients underwent 47 procedures, the average age of the patients was 43 years and the male to female ratio was 1:22. Undertaken were 30 lobectomies, 3 subtotal thyroidectomies, 13 total thyroidectomies and 1 totalization. One case was converted to an open procedure. The ratio of malignant to benign disease was 1:6.67 (6:40 cases) and analysis of the surgical specimens showed 6 follicular lesions, 24 follicular adenomas, 3 colloid lesions, 1 case of thyroiditis/lymphatic lesion, 3 adenomatoid lesions, 3 oncocytic adenomas, 3 papillary cancers and 3 microcapillary cancers. The overall average size of an individual specimen removed was 45.40 ± 28.95 cm(3) (range 5-160, n = 47) and the average largest diameter of the lesion removed was 3.72 ± 0.95 cm (range 1.4-6.0, n = 47). Postoperatively, there were 5 recurrent laryngeal nerve injuries (4 transient), 2 transient brachial plexopathies, 1 case of postoperative dysphagia and 1 of collection of blood at the site of surgery. There were no cases of disease recurrence at follow-up.

CONCLUSIONS

The gasless robotic transaxillary approach to thyroid surgery has been predicted to become a standard technique. It has been shown to be efficacious in the management of thyroid cancer with lateral neck metastases; however, more data relating to oncological safety in long-term follow-up is required. This intervention is also appropriate for benign thyroid disease including Graves' disease. To achieve consistently successful results, careful patient selection is fundamental in terms of patient characteristics and the anatomical aspects of the lesion. This is especially important with a geographical expansion to include North America and Europe. The excellent cosmetic results of this procedure make it ideal for patients who have esthetic concerns regarding particular difficulties with healing; however, in common with all new surgical procedures, further evidence must be sought to confirm its indications over time.