Hypothyroidism after hemithyroidectomy

Incidence and risk factors for early thyroxin supplementation therapy after hemithyroidectomy for benign conditions in Europe. A Eurocrine® registry-based study

The incidence and risk factors of hypothyroidism after hemithyroidectomy (HT) remain poorly defined. Regarding its management, national or local policies may influence on early (first visit) prescription of replacement therapy (EPRT). Our aim was to identify factors influencing and explaining different prescription patterns across European countries. We conducted a retrospective, multicenter study using the Eurocrine® database, focusing on patients undergoing HT for histologically-proven benign conditions. Analyzed variables included the country where surgery was performed, as well as epidemiological, clinical, surgical and pathological data. The dependent variable was EPRT, assessed 30-45 days after surgery. Associations between qualitative variables and the likelihood of receiving EPRT were tested using Chi-square or Fisher's exact tests. A multivariate logistic regression model was developed to identify independent predictors. 14,484 patients undergoing HT between 2015 and 2022 were included. Median age was 52 years, and 11,345 (78.3%) were female. The most common indication for surgery was excluding malignancy in 7873 cases (54.3%). Overall, 4653 patients (32.1%) received EPRT, with significant variability among countries, ranging from 3 to 95%. Independent risk factors for EPRT included female sex, older age, malignancy and thyrotoxicosis as surgical indications, Bethesda III cytology, thyroiditis on histology, and the country where HT was performed. One-third of European patients undergoing HT for confirmed benign conditions required EPRT. That prescription was more likely among older patients, those with suspected malignancy or thyrotoxicosis as surgical indications, suspicious cytology, and thyroiditis on histology. Additionally, the country where surgery was done played a significant role.

Prevalence of and Predictive Factors for Hypothyroidism Following Hemithyroidectomy

PURPOSE

Hemithyroidectomy is an appropriate procedure that is recommended for a number of thyroid conditions to preserve the functional contralateral thyroid lobe, but patients who underwent a hemithyroidectomy still run the risk of developing hypothyroidism. This study aimed to determine the incidence of hypothyroidism following a hemithyroidectomy as well as predictive risk factors.

METHODS

A retrospective analysis was carried out on all patients who underwent hemithyroidectomy between 2016 and 2022. Age, gender, preoperative and postoperative thyroid stimulating hormone (TSH) and free thyroxin (FT4), side, and volume of the remaining lobe, as well as the histologic diagnosis, were all examined in the patients. To identify the predictors of hypothyroidism, statistical analyses, both univariate and multivariate, were conducted.

RESULTS

Out of 224 patients, 18.25% had hypothyroidism following surgery. This complication appeared within the first year in 88% of the cases. Patients with thyroiditis (P = .036), preoperative TSH levels greater than 1.72 mIU/L (P < .001), right side hemithyroidectomy (P = .017), and residual lobe volume less than 3.57 cm (P < .001) had a significantly higher risk of developing hypothyroidism.

CONCLUSION

After hemithyroidectomy, hypothyroidism is a major complication that should be carefully evaluated preoperatively based on risk factors of hypothyroidism. Furthermore, our results confirm the need for routine serum TSH monitoring for a minimum of 1 year following hemithyroidectomy.

Role of Preoperative Thyroid-Stimulating Hormone Levels in the Prediction of Thyroid Hormone Replacement after Hemithyroidectomy

Introduction  Hemithyroidectomy is performed for the treatment of symptomatic unilateral benign nodules, cytologically indeterminate nodules, and some cases of well-differentiated thyroid cancer. Objective  To evaluate the frequency of postlobectomy thyroid hormone replacement (THR), and to analyze the clinical-pathological factors predicting L-thyroxine (T4) use in patients undergoing hemithyroidectomy. Methods  We conducted an observational, retrospective study in which clinical, biochemical, and anatomopathological parameters were analyzed and correlated with the need for THR after thyroid lobectomy. Results  The frequency of postoperative THR was 63%. The preoperative thyroid-stimulating hormone (TSH) level was an important predictor of postoperative THR. When stratifying preoperative TSH levels, the frequencies of T4 replacement in each TSH quartile varied, being more frequent with increasing presurgical TSH levels ( p  = 0.029). The preoperative cutoff that maximized sensitivity and specificity for the development of hypothyroidism was 1.21 μIU/mL. Conclusion  Our results demonstrated a significant frequency of postlobectomy THR. Higher preoperative TSH is a strong risk factor for postsurgical hypothyroidism, and even lower preoperative levels within the normal references do not exclude the risk of thyroid hormone use after thyroid lobectomy.

Hypothyroidism After Hemithyroidectomy: A Retrospective Analysis of Temporal Trends and Key Risk Factors

Background/Objectives: Post-hemithyroidectomy hypothyroidism is a recognized complication, though its incidence and risk factors remain variably reported. This study aimed to determine the incidence of hypothyroidism post-hemithyroidectomy, identify associated risk factors, and assess temporal changes in thyroid hormone levels. Methods: This retrospective analysis examined the records of 192 euthyroid patients who underwent hemithyroidectomy between January 2019 and May 2023. Thyroid function was assessed preoperatively and at 1, 6, and 12 months postoperatively. Kaplan-Meier survival analysis and Cox proportional hazards regression were used to evaluate the time to hypothyroidism onset and identify significant predictors. Results: At 1 month postoperatively, a higher incidence was observed in elderly patients (>65 years; 31.11%) and those aged 56-65 years (29.54%), compared to younger age groups (7.69% in patients aged 18-35 years). The incidence decreased over time, with 14.06% and 10.94% of patients being hypothyroid at 6 and 12 months, respectively. Severe obesity was associated with the highest hypothyroidism rates across all follow-up periods, particularly at 1 month (50.00%). Elevated BMI was also associated with increased risk, particularly in overweight patients (HR = 2.368, 95% CI 1.016-5.523). Patients undergoing left-sided hemithyroidectomy had a higher incidence of hypothyroidism at 12 months compared to right-sided hemithyroidectomy patients (15.63% vs. 6.25%, p = 0.037). Cox regression analysis confirmed diabetes and BMI (overweight) as significant predictors of hypothyroidism. Conclusions: Hypothyroidism is a common complication following hemithyroidectomy, particularly in elderly and overweight patients. The significant early onset of thyroid dysfunction underscores the need for routine postoperative monitoring, especially within the first year.

Association of obesity with orbital fat expansion in thyroid eye disease

BACKGROUND

To investigate the association between obesity and orbital fat expansion in proptosis of thyroid eye disease.

METHODS

This observational study retrospectively enrolled 87 participants who received orbital fat decompression surgery for thyroid eye disease. Primary outcome measures included average body mass index (BMI) and the proportion of the study sample with overweight and obesity, compared with the general Taiwanese population. Secondary outcome measures included the association of obesity with proptosis severity, removed fat volume, and thyroid status.

RESULTS

The average BMI (25.59 ± 4.36 kg/m2) of the study sample was significantly higher than that in the general population of Taiwan (24.5 kg/m2; P = 0.012). Participants with overweight (19.52 ± 3.52 mm) and obesity (21.25 ± 3.76 mm) exhibited significantly more severe proptosis than participants without overweight (18.05 ± 3.37 mm) and without obesity (18.09 ± 3.02 mm; P = 0.029 and P < 0.001, respectively). In addition, a significantly greater orbital fat volume was removed from the group with obesity (4.61 ± 1.17 ml) versus that without obesity (3.57 ± 1.12 ml; P = 0.021). A positive correlation between BMI and removed fat volume was noted (correlation coefficient = 0.291, P = 0.005). BMI was an independent factor predicting both proptosis severity (P < 0.001) and removed orbital fat volume (P = 0.02).

CONCLUSIONS

Obesity is associated with orbital fat expansion and consequently more severe proptosis in thyroid eye disease. Weight control may be a potential strategy to prevent thyroid-associated exophthalmos.

Hypothyroidism after hemithyroidectomy: a systematic review and meta-analysis

BACKGROUND

The incidence of hypothyroidism following hemithyroidectomy and risk factors associated with its occurrence are not completely understood. This systematic review investigated the incidence and risk factors for hypothyroidism, thyroxine supplementation following hemithyroidectomy as well as the course of post-operative hypothyroidism, including the time to hypothyroidism and incidence of transient hypothyroidism.

METHODS

Searches were conducted in MEDLINE, EMBASE, Scopus, and Cochrane library for studies reporting the incidence of hypothyroidism or thyroxine supplementation following hemithyroidectomy.

RESULTS

Sixty-six studies were eligible for inclusion: 36 reported risk factors, and 27 reported post-operative course of hypothyroidism. Median follow-up was 25.2 months. The pooled incidence of hypothyroidism was 29% (95% CI, 25-34%; P<0.001). Transient hypothyroidism occurred in 34% of patients (95% CI, 21-47%; P<0.001). The pooled incidence of thyroxine supplementation was 23% (95% CI, 19-27%; P<0.001), overt hypothyroidism 4% (95% CI, 2-6%, P<0.001). Risk factors for development of hypothyroidism included pre-operative thyroid stimulating hormone (TSH) (WMD, 0.87; 95% CI, 0.75-0.98; P<0.001), TSH ≥ 2 mIU/L (RR, 2.87; 95% CI, 2.43-3.40; P<0.001), female sex (RR, 1.19; 95% CI, 1.08-1.32; P=0.007), age (WMD, 2.29; 95% CI, 1.20-3.38; P<0.001), right sided hemithyroidectomy (RR, 1.35; 95% CI, 1.10-1.65, P=0.003), the presence of autoantibodies anti-TPO (RR, 1.92; 95% CI, 1.49-2.48; P<0.001), anti-Tg (RR, 1.53; 95% CI, 1.40-1.88; P<0.001), and Hashimoto's thyroiditis (RR, 2.05; 95% CI, 1.57-2.68; P=0.001).

CONCLUSION

A significant number of patients will develop hypothyroidism or require thyroxine following hemithyroidectomy. An awareness of patient risk factors and postoperative thyroid function course will assist in counselling patients on their risk profile and guiding management.

Development of hypothyroidism following hemithyroidectomy: A population-based study

PURPOSE

Hypothyroidism is a known possibility after hemithyroidectomy, with a highly variable incidence in the literature ranging from 8 to 60 %. Incidence of hypothyroidism after hemithyroidectomy was evaluated with a secondary aim to assess incidence in patients with Hashimoto's disease.

MATERIALS & METHODS

A retrospective study using the TriNetX global federated research network was performed. We included patients within the last 15 years that were ≥18 years of age and had Current Procedural Terminology codes for hemithyroidectomy. Patients were excluded if they had a total or completion thyroidectomy at any time, a history of thyroid cancer, were preoperatively either on levothyroxine, diagnosed with hypothyroidism, or had a Thyroid Stimulating Hormone ≥ 4 m[IU]/L. We assessed the 3 month incidence of hypothyroidism postoperatively based on the International Classification of Diseases code, TSH ≥ 4 m[IU]/L, or taking levothyroxine after surgery.

RESULTS

6845 patients met the inclusion criteria. Most of the cohort was female (67 %) and white (63 %). The mean age at surgery for this population was 54 ± 14.8 years. During the 15 years of data, we found the 3-month incidence of hypothyroidism following hemithyroidectomy to be 23.58 %. The median time to develop the disease was 41.8 months. A subgroup analysis of those with Hashimoto's revealed a 3-month incidence of 31.1 % of patients developing hypothyroidism after surgery.

CONCLUSIONS

This population-based study gives additional insight into the incidence of hypothyroidism after hemithyroidectomy. This will help improve perioperative patient counseling and management.

Comparison of Micro-flow Imaging and Contrast-Enhanced Ultrasound in Ultrasound-Guided Microwave Ablation of Benign Thyroid Nodules

OBJECTIVE

The study described here was aimed at ascertaining the utility of micro-flow imaging (MFI) during ultrasound (US)-guided microwave ablation (MWA) of thyroid nodules by contrasting its effectiveness with that of contrast-enhanced ultrasound (CEUS).

METHODS

Seventy-three patients with eighty-eight thyroid nodules who underwent US-guided MWA were included in our study from January 2020 to June 2023. Thirty-five patients underwent CEUS during the MWA process, and thirty-eight patients underwent MFI during the MWA process. We compared the two groups' baseline characteristics, tumor volume (V), volume reduction rate (VRR), complications and clinical characteristics.

RESULTS

Both groups exhibited similar outcomes with respect to V and VRR at 1, 3, 6, 12 and 18 mo after MWA (p > 0.05). Consistency was observed with respect to post-operative complications, supplementary ablation times and surgical duration (p > 0.05). It is worth noting that the MFI group had lower treatment costs compared with the CEUS group (11,337.64 ± 80.93 yuan for the MFI group versus 12,971.23 ± 254.89 yuan for the CEUS group, p < 0.05).

CONCLUSION

In the MWA procedure for thyroid nodules, MFI is similar to CEUS with respect to safety and efficacy. Simultaneously, it offers the advantage of reducing surgical expenses, which lessens the economic burden for patients.

Posthemithyroidectomy Hypothyroidism: Updated Meta-Analysis of Risk Factors and Rates of Remission

INTRODUCTION

The aim of this study was to determine the incidence and risk factors for hypothyroidism, both clinical and subclinical, following hemithyroidectomy in preoperatively euthyroid patients, as well as hypothyroidism remission and its time of remission.

MATERIALS AND METHODS

A search was performed in Medline (via PubMed), Web of Science, and the Cochrane Library using the keywords "hemithyroidectomy + postoperative + hypothyroidism" and "hemithyroidectomy + hormone supplementation".

RESULTS

Fifty-four studies with a total of 9,999 patients were included. After a mean follow-up interval of 48.2 mo, the pooled hypothyroidism rate was 29%. The subclinical hypothyroidism rate was 79% of patients with hypothyroidism (18 studies). Moreover, a meta-analysis of 12 studies indicated a pooled hypothyroidism remission rate after hemithyroidectomy of 42% (95% CI: 24%-60%). Older patient age (MD = -2.54, 95% CI = -3.99, -1.10, P = 0.0006), female gender (OR = 0.69, 95% CI = 0.58, 0.82, P < 0.0001), higher preoperative thyroid-stimulating hormone levels (MD = -0,81, 95% CI = -0.96, -0.66, P < 0.00001), pathological preoperative anti-thyroid peroxidase antibodies (OR = 0.37, 95% CI = 0.24, 0.57, P < 0.00001) and anti-thyroglobulin antibodies (OR = 0.52, 95% CI = 0.36, 0.75, P = 00,005), and right-sided hemithyroidectomy (OR = 0.54, 95% CI = 0.43, 0.68, P < 0.00001) were associated with postoperative hypothyroidism development. In metaregression analysis, Asia presented a significantly higher hypothyroidism rate after hemithyroidectomy (34.6%, 95% CI = 29.3%-9.9%), compared to Europe (22.9%, 95% CI = 16.2%-29.5%, P = 0.037) and Canada (1.8%, 95% CI = -22.6%-26.2%, P = 0.013).

CONCLUSIONS

Hypothyroidism is a frequent and significant postoperative sequela of hemithyroidectomy, necessitating individualization of treatment strategy based on the underlying disease as well as the estimated risk of hypothyroidism and its risk factors.

Risk factors for hypothyroidism following hemithyroidectomy

OBJECTIVE

Hypothyroidism is the most common complication of hemithyroidectomy for thyroid nodules. This retrospective cohort study investigated the prognostic factors for hypothyroidism following hemithyroidectomy.

METHODS

We included patients who underwent hemithyroidectomy between 2016 and 2017, excluding those with history of preoperative hypothyroidism or malignancy on histopathological examination. The primary endpoint was development of hypothyroidism during follow-up (TSH≥2 above normal).

RESULTS

Twenty-six of the 128 included patients (20%) developed postoperative hypothyroidism. The following independent prognostic factors were found: preoperative TSH level>1.5 mIU/L (OR 2.11; P=0.013), and remaining thyroid volume adjusted for body surface area<4.0mL/m2 (OR 1.77; P=0.015). Twenty-one patients (81%) had first TSH values above the upper limit of normal. Postoperatively, first TSH level correlated significantly with the preoperative value (R=0.5779, P<0.001). Levothyroxine was prescribed to 16% of patients, with a mean dose of 0.92μg/kg/day.

CONCLUSION

Patients with TSH>1.5 mIU/or remaining thyroid volume adjusted for body surface area<4.0mL/m2 should have intensified clinical and biological follow-up in the first year after surgery.

Artificial Intelligence for Pre-operative Diagnosis of Malignant Thyroid Nodules Based on Sonographic Features and Cytology Category

BACKGROUND

Current diagnosis and classification of thyroid nodules are susceptible to subjective factors. Despite widespread use of ultrasonography (USG) and fine needle aspiration cytology (FNAC) to assess thyroid nodules, the interpretation of results is nuanced and requires specialist endocrine surgery input. Using readily available pre-operative data, the aims of this study were to develop artificial intelligence (AI) models to classify nodules into likely benign or malignant and to compare the diagnostic performance of the models.

METHODS

Patients undergoing surgery for thyroid nodules between 2010 and 2020 were recruited from our institution's database into training and testing groups. Demographics, serum TSH level, cytology, ultrasonography features and histopathology data were extracted. The training group USG images were re-reviewed by a study radiologist experienced in thyroid USG, who reported the relevant features and supplemented with data extracted from existing reports to reduce sampling bias. Testing group USG features were extracted solely from existing reports to reflect real-life practice of a non-thyroid specialist. We developed four AI models based on classification algorithms (k-Nearest Neighbour, Support Vector Machine, Decision Tree, Naïve Bayes) and evaluated their diagnostic performance of thyroid malignancy.

RESULTS

In the training group (n = 857), 75% were female and 27% of cases were malignant. The testing group (n = 198) consisted of 77% females and 17% malignant cases. Mean age was 54.7 ± 16.2 years for the training group and 50.1 ± 17.4 years for the testing group. Following validation with the testing group, support vector machine classifier was found to perform best in predicting final histopathology with an accuracy of 89%, sensitivity 89%, specificity 83%, F-score 94% and AUROC 0.86.

CONCLUSION

We have developed a first of its kind, pilot AI model that can accurately predict malignancy in thyroid nodules using USG features, FNAC, demographics and serum TSH. There is potential for a model like this to be used as a decision support tool in under-resourced areas as well as by non-thyroid specialists.

Morphological, clinical, and functional efficacy in the short and medium-term after radiofrequency treatment of predominantly solid, large, and clinically relevant thyroid nodules in patients who are not candidates for surgery: The experience after 100 procedures

INTRODUCTION

Thyroid nodules (TN) are a prevalent pathology that can generate morbidity, in which case the traditional treatment is usually surgery.

OBJECTIVE

To analyse the efficacy of radiofrequency ablation (RFA) treatment as a therapeutic alternative in the combined clinical, morphological, and functional control of predominantly solid, benign and clinically relevant TNs in patients not subsidiary to surgery.

MATERIALS AND METHODS

A descriptive, retrospective, case series study was carried out to assess the efficacy and safety of the use of RFA. According to medical criteria, the selected patients underwent a clinical, ultrasound, and biochemical assessment prior to the procedure and then after the procedure at 1, 3, 6, and 12 months and then every 6-12 months according to medical criteria.

RESULTS

A total of 100 RFA were performed on 83 patients with 85 TNs of ≥2.5 cm with an initial volume (IV) of 21.48 ± 15.89 ml. After a mean of 1.17 RFA sessions per TN, the volume decreased progressively and significantly (p < 0.01 for all times compared to the initial value), with a mean volume reduction rate (VRR) in relation to the IV of 54.43 ± 19.56% at 1-month follow-up; 67.69 ± 17% at 3 months; 70.38 ± 15.46% at 6 months; 70.67 ± 17.27% at 12 months and 70.24 ± 17.7% at the last follow-up. 88% of the patients followed up >6 months achieved the combined objective of a volume reduction rate of more than 50% of the VI, thyroid normal function and absence of clinic; and in all of these, it was maintained until the final follow-up date. Acute complications (mostly mild and all transient) were reported in 9 of the 100 RFA performed.

CONCLUSION

Our findings validate in our setting the efficacy and safety of RFA in predominantly large and solid TNs, and add undescribed information to position the technique more favourably as a therapeutic alternative.

Time to Hypothyroidism Following Hemithyroidectomy

Background The time to hypothyroidism post hemithyroidectomy is variable. There are multiple risk factors for developing hypothyroidism. The aim of this study was to identify the time of hypothyroidism and other predictors of hypothyroidism in euthyroid patients following hemithyroidectomy. Methods This was a retrospective study. Of 170 euthyroid patients who underwent hemithyroidectomy for benign disease between 2006 - 2014, age, gender, pre-operative thyroid function tests, body mass index (BMI), and other co-morbidities were examined to determine predictors of early (<3 months) or late (>3 months) hypothyroidism. A high normal preoperative thyroid stimulating hormone (HN-TSH) was defined as ≥2.01 uIU/ml, and a low normal TSH (LN-TSH) was defined as <2.01 uIU/ml. Results A total of 63 of the 170 patients (37%) became hypothyroid. At 3 months, 21.5% of patients were hypothyroid. At 6 months after operation, an additional 5% had become hypothyroid, and after 1 year, 8% more were hypothyroid. The only independent predictor of hypothyroidism was preoperative HN-TSH (≥2.01) (p<0.001) on multivariate analysis. Conclusion In addition to known predictors of hypothyroidism following hemithyroidectomy for benign disease, such as the size of the thyroid remnant, a history of neck irradiation, and coexisting thyroid autoimmune disease, a BMI ≥35 kg/m², age ≥45, and preoperative HN-TSH are risk factors for postoperative hypothyroidism within 3 months of operation. Such patients should be closely monitored.

Predictive factors for hypothyroidy after hemithyroidectomy

Background: Hemithyroidectomy is one of the most common procedures performed. It is used to treat patients with benign unilateral nodules. Hemithyroidectomy results in fewer risks of hypothyroidism and the need for thyroid hormone replacement therapy. The present study was designed to identify potential clinicopathologic risk factors associated with the onset of biochemical hypothyroidism. Methods: We conducted a retrospective review of all patients who underwent hemithyroidectomy between 2004 and 2019. Hypothyroidism was defined as a serum thyrotropin level greater than 5 mIU/L. The patients were analyzed for age, sex, preoperative and postoperative thyroid stimulating hormone (TSH), state, side, and volume of the remaining lobe, and histologic diagnosis. Results: Hypothyroidism was diagnosed in 30.8% of 214 patients. This complication appeared in the first year in 83.3% of the cases. A preoperative TSH level greater than 1.32 mIU/l, a remaining volume of the lobe less than 3 ml, and the presence of thyroiditis were associated with a significant increase in the risk of developing hypothyroidism (p<0.01). There were no significant differences in age, sex, state, and side of the remaining lobe. The mean thyroxine dose was 57 ± 26 micrograms. Conclusions: The risk of hypothyroidism after hemithyroidectomy should be assessed prior to surgery. Close monitoring is recommended in patients at high risk of developing this complication. However, all patients who undergo hemithyroidectomy should be monitored at least for the first year.

Predictive factors for hypothyroidy after hemithyroidectomy

Background: Hemithyroidectomy is one of the most common procedures performed. It is used to treat patients with benign unilateral nodules. Hemithyroidectomy results in fewer risks of hypothyroidism and the need for thyroid hormone replacement therapy. The present study was designed to identify potential clinicopathologic risk factors associated with the onset of biochemical hypothyroidism. Methods: We conducted a retrospective review of all patients who underwent hemithyroidectomy between 2004 and 2019. Hypothyroidism was defined as a serum thyrotropin level greater than 5 mIU/L. The patients were analyzed for age, sex, preoperative and postoperative thyroid stimulating hormone (TSH), state, side, and volume of the remaining lobe, and histologic diagnosis. Results: Hypothyroidism was diagnosed in 30.8% of 214 patients. This complication appeared in the first year in 83.3% of the cases. A preoperative TSH level greater than 1.32 mIU/l, a remaining volume of the lobe less than 3 ml, and the presence of thyroiditis were associated with a significant increase in the risk of developing hypothyroidism (p<0.01). There were no significant differences in age, sex, state, and side of the remaining lobe. The mean thyroxine dose was 57 ± 26 micrograms. Conclusions: The risk of hypothyroidism after hemithyroidectomy should be assessed prior to surgery. Close monitoring is recommended in patients at high risk of developing this complication. However, all patients who undergo hemithyroidectomy should be monitored at least for the first year.

Assessment of Radiofrequency Ablation for Papillary Microcarcinoma of the Thyroid: A Systematic Review and Meta-analysis

IMPORTANCE

Papillary microcarcinomas of the thyroid (mPTCs) account for an increasing proportion of thyroid cancers in past decades. The use of radiofrequency ablation (RFA) has been investigated as an alternative to surgery. The effectiveness and safety of RFA has yet to be determined.

OBJECTIVE

To evaluate the effectiveness and safety of RFA for low-risk mPTC.

DATA SOURCES

Embase, MEDLINE via Ovid, Web of Science Core Collection, Cochrane Central Register of Controlled Trials, and the top 100 references of Google Scholar were searched from inception to May 28, 2021.

STUDY SELECTION

Articles reporting on adult patients with mPTC treated with RFA were included. Studies that involved patients with pre-ablation lymph node or distant metastases, recurrence of disease, or extrathyroidal extension were excluded. Final article selection was conducted by multiple reviewers based on consensus. The proportion of eligible articles was 1%.

DATA EXTRACTION AND SYNTHESIS

This meta-analysis was conducted in accordance with the MOOSE guidelines. Random and fixed-effect models were applied to obtain pooled proportions and 95% CIs.

MAIN OUTCOMES AND MEASURES

The primary outcome was the complete disappearance rate of mPTC. Secondary outcomes were tumor progression and complications.

RESULTS

Fifteen studies were included in this meta-analysis. A total of 1770 patients (1379 women [77.9%]; mean [SD] age, 45.4 [11.4] years; age range, 42.5-66.0 years) with 1822 tumors were treated with RFA; 49 tumors underwent 1 additional RFA session and 1 tumor underwent 2 additional RFA sessions. Mean (SD) follow-up time was 33.0 (11.4) months (range, 6-131 months). The pooled complete disappearance rate at the end of follow-up was 79% (95% CI, 65%-94%). The overall tumor progression rate was 1.5% (n = 26 patients), local residual mPTC in the ablation area was found in 7 tumors (0.4%), new mPTC in the thyroid was found in 15 patients (0.9%), and 4 patients (0.2%) developed lymph node metastases during follow-up. No distant metastases were detected. Three major complications occurred (2 voice changes lasting >2 months and 1 cardiac arrhythmia). Minor complications were described in 45 patients.

CONCLUSIONS AND RELEVANCE

The findings of this systematic review and meta-analysis suggest that RFA is a safe and efficient method to treat selected low-risk mPTCs. Radiofrequency ablation could be envisioned as step-up treatment after local tumor growth under active surveillance for an mPTC or initial treatment in patients with mPTCs with anxiety about active surveillance.

Risk factors for thyroid hormone replacement therapy after hemithyroidectomy and development of a predictive nomogram

PURPOSE

Hemithyroidectomy is a valid operation to retain functional contralateral thyroid lobe that is indicated for a variety of thyroid diseases. This study aimed at determination of the risk factors for thyroid hormone replacement following hemithyroidectomy and to develop a predictive nomogram.

METHODS

Data of patients treated by hemithyroidectomy for benign thyroid disease between January 2015 and January 2020 were retrospectively analyzed. Baseline characteristics, surgery-related variables, and preoperative and postoperative thyroid function of patients were collected from the case records and compared between patients with postoperative euthyroidism and patients with postoperative hypothyroidism. Postoperative euthyroidism patients without thyroid hormone replacement were compared to those who developed postoperative hypothyroidism with thyroid hormone replacement. The factors associated with thyroid hormone replacement were used to construct a binomial logistic-regression model and visualized as a predictive nomogram to evaluate the risk of thyroid hormone replacement following hemithyroidectomy.

RESULTS

Of the 378 patients (74% female) included in the study, 110 (29.1%) developed postoperative hypothyroidism. Preoperative serum thyroid-stimulating hormone (TSH) > 2.172 μIU/mL was identified as an independent risk factor for postoperative hypothyroidism (odds ratio [OR] = 8.02; 95% confidence interval [CI]: 4.87-13.20; P < 0.001). Of 110 patients with postoperative hypothyroidism, 56 (50.9%) received thyroid hormone replacement. Unilateral thyroid nodule and preoperative serum TSH > 2.172 μIU/mL were independent predictors of postoperative thyroid hormone replacement (P = 0.01, and P < 0.001, respectively). Temporary subclinical hypothyroidism occurred in 12 patients; all 12 reverted to euthyroid state without thyroid hormone replacement. The discriminative effect of the binomial regression model was proved reliable by the Hosmer-Lemeshow goodness-of-fit test (P = 0.503), and predictive ability of the nomogram was satisfactory with a C-index of 0.833.

CONCLUSIONS

Hypothyroidism is common after hemithyroidectomy, and almost half of the patients will need thyroid hormone replacement. Elevated preoperative serum TSH level and unilateral thyroid nodule were independent predictors of thyroid hormone replacement following hemithyroidectomy. The predictive nomogram could be a useful tool for clinical practice.

Radiofrequency ablation for symptomatic, non-functioning, thyroid nodules: a single-center learning curve

OBJECTIVE

Radiofrequency ablation (RFA) is increasingly considered the prime option for treating symptomatic, benign, non-functioning thyroid nodules (NFTN). However, little is known about the degree of operator experience required to achieve optimal results. This study describes the RFA learning curve of a single-center team.

METHODS

A retrospective cohort study of the first 103 patients receiving RFA treatment for a single, symptomatic, and benign NFTN, with a follow-up of at least 1 year. The primary outcome measure was technique efficacy, defined as the percentage of patients with a 6-month nodal volume reduction ratio (VRR) >50% after single-session RFA. Optimal treatment efficacy was defined as a 6-month VRR >50% achieved in at least 75% of patients. Secondary outcomes were complications of RFA and indications of secondary interventions.

RESULTS

Median nodal volume at baseline was 12.0 mL (range 2.0-58.0 mL). A 6-month VRR >50% was achieved in 45% of the first 20 patients, 75% of the next 20, and 79% of the following 63 patients. Complications included minor bleeding (N = 4), transient hyperthyroidism (N = 4), and transient loss of voice (N = 1). Poor volume reduction or nodular regrowth led to diagnostic lobectomy in 11 patients and a second RFA in 5. Lobectomy revealed a follicular carcinoma (T2N0M0) in 2 patients. In 1 patient, nodule regrowth was caused by an intranodular solitary B-cell lymphoma.

CONCLUSION

About 40 procedures are required to achieve a 6-month VRR >50% in the majority of patients. Appropriate follow-up with re-evaluation is recommended for all patients with a VRR <50% and in those with regrowth to exclude underlying malignancy.

Thermal ablation for papillary thyroid microcarcinoma located in the isthmus: a study with 3 years of follow-up

Aims: To analyze the outcomes of thermal ablation for isthmic papillary thyroid microcarcinoma (PTMC). Patients & methods: Data for 21 isthmic-PTMC patients who underwent microwave ablation under ultrasound guidance were retrospectively collected. General information on patients and characteristics of tumors were collected. The technical effectiveness, tumor recurrence and volume changes and postoperative complications were recorded during the follow-up. Comparisons with 105 nonisthmic-PTMCs were done. Results: The technical effectiveness was 100%. No recurrence or lymph node metastases were detected. Tumor volume decreased significantly with a volume reduction rate of 1.00 ± 0.01 (range: 0.99 to 1.0) at the final evaluation and seven cases (31.8%) were completely resolved. No complication was encountered. No statistical differences were observed in terms of complications, recurrence or the volume reduction rate compared with the nonisthmic group (all p > 0.05). Conclusions: Percutaneous microwave ablation is an effective treatment strategy for isthmic-PTMC.

Changes in Thyroid Antibodies after Microwave Ablation of Thyroid Nodules

PURPOSE

Microwave ablation (MWA) is a minimally invasive method for the thermal ablation of benign thyroid nodules and papillary thyroid cancer (PTC) and has shown promising results. The aim of this study was to investigate the impact of MWA on thyroid antibodies and associated influencing factors.

MATERIALS AND METHODS

A total of 119 patients, including 69 with benign thyroid nodules and 50 with PTC, underwent MWA between June 2019 and June 2021. The serum levels of (free) triiodothyronine, (free) thyroxine, thyrotropin, and antibodies against Tg (TGAb), thyrotropin receptors (TRAb), and thyroid peroxidase (TPOAb) were measured during the follow up.

RESULTS

One month after ablation, three patients (4.3%) in the benign group had hypothyroidism, and one (1.4%) had hyperthyroidism. Four patients (5.8%) had subclinical hypothyroidism, and two (2.9%) had subclinical hyperthyroidism. Among the PTC patients, two (4%) had hypothyroidism, and one (2%) had hyperthyroidism. Two patients (4%) had subclinical hypothyroidism, and one (2%) had subclinical hyperthyroidism. In the benign group, among patients with normal preablation antibodies, the postablation TGAb abnormal rate was 12.7%, the TPOAb level was 4.8%, and the TRAb level was 0%. Among PTC patients, the postablation TGAb abnormal rate was 11.4%, the TPOAb level was 8.7%, and the TRAb level was 4.0%. The cutoff value of preablation TGAb for predicting postoperative antibody abnormalities was 19.0 IU/mL, while that of TPOAb was 11.4 IU/mL.

CONCLUSIONS

MWA of thyroid nodules had little influence on thyroid function and antibodies. Elevations in TGAb, TPOAb, and TRAb beyond the normal ranges after MWA may be related to high preablation levels of TGAb and TPOAb.

Correlation and agreement between superb micro-vascular imaging and contrast-enhanced ultrasound for assessing radiofrequency ablation treatment of thyroid nodules: a preliminary study

Background

To evaluate the correlation and agreement between superb micro-vascular imaging (SMI) mode and the contrast-enhanced ultrasound (CEUS) mode for the ablative completeness and the volumes of ablation lesions to determine the clinical application value of SMI in follow-up after radiofrequency ablation.

Methods

From April 2020 to June 2020, two radiologists used SMI and CEUS mode to measure the volume of the ablation lesion. We use intra-class correlation coefficient (ICC), scatter plots and Bland–Altman plots to evaluate the correlation and agreement of the two techniques. In addition, intra- and inter-observer reliability in volume measurement of ablation lesions with SMI mode was assessed.

Results

SMI mode and CEUS mode have good agreement in the evaluation of ablative completeness. The ICC was 0.876 and 0.928 of reader A and reader B between SMI mode and CEUS mode in terms of ablation lesions volume measurement. There was a strong correlation between the two modes in both reader A and reader B (r_A = 0.808; r_B = 0.882). The ICC was 0.836 for the inter-observer reliability of SMI technique. The scatter plot showed a good linear relation (r = 0.715). In the Bland–Altman plot, 4.35% (1/23) of the points was outside the 95% limits of agreement. The ICC was 0.965 for the intra-observer reliability of SMI technique, the scatter plot also showed a strong linear correlation (r = 0.965). In the Bland–Altman plot, 8.70% (2/23) of the points was outside the 95% limits of agreement.

Conclusions

SMI and CEUS have good agreement and correlation in the ablation volume measurement. SMI technology is expected to be applied as an alternative to CEUS in the clinical follow-up of ablation lesions.

Risk factors for hypothyroidism and thyroid hormone replacement after hemithyroidectomy in papillary thyroid carcinoma

PURPOSE

Thyroid lobectomy is now preferred over total thyroidectomy to preserve thyroid function and reduce complications in patients with low-risk papillary thyroid carcinoma (PTC). One inevitable consequence of thyroidectomy includes hypothyroidism. This study aimed to evaluate the risk factors for hypothyroidism and thyroid hormone replacement after hemithyroidectomy in patients with PTC.

METHODS

We retrospectively studied 353 patients with PTC who underwent hemithyroidectomy with or without central neck dissection from January 2012 to January 2019. We excluded patients who had hypo- or hyperthyroidism preoperatively and those who underwent total or subtotal thyroidectomy. We analyzed various risk factors related to postoperative hypothyroidism and thyroid hormone supplementation.

RESULTS

Of the patients, 54.7% showed hypothyroidism after hemithyroidectomy (n=193 with n=157, subclinical hypothyroidism; n=36, overt hypothyroidism). Ninety-one percent of postoperative hypothyroidism cases developed within 7 months postoperatively. Eventually, 43.1% (n=152) of patients received levothyroxine after hemithyroidectomy. Preoperative high thyroid-stimulating hormone (TSH) level and low free thyroxine (fT4) level were significantly associated with postoperative hypothyroidism and the need for thyroid hormone supplementation postoperatively.

CONCLUSION

Preoperative TSH and fT4 levels are predictive risk factors of hypothyroidism and need for supplementation of levothyroxine after hemithyroidectomy in patients with PTC. Finally, approximately 43% of patients need levothyroxine supplementation after hemithyroidectomy, and individual preoperative counseling is necessary for these patients.

Does thyroid-sparing total laryngectomy decrease the risk of hypothyroidism?

BACKGROUND

Thyroid lobectomy is recommended with total laryngectomy for laryngeal cancer in the National Comprehensive Cancer Network ('NCCN') guidelines. However, it is associated with a 32-89 per cent risk of hypothyroidism, with or without adjuvant radiotherapy.

OBJECTIVE

The study aimed to determine whether preserving the whole thyroid, compared to a single lobe, does indeed significantly lower the incidence of hypothyroidism in the setting of total laryngectomy.

METHOD

A retrospective study was conducted at Groote Schuur Hospital in Cape Town, South Africa.

RESULTS

Eighty-four patients met the inclusion criteria. The overall incidence of hypothyroidism was 45.2 per cent. The incidence of hypothyroidism was significantly reduced in patients who underwent thyroid-sparing total laryngectomy compared to hemithyroidectomy (p = 0.037). Adjuvant radiotherapy was associated with a higher incidence of hypothyroidism (p = 0.001).

CONCLUSION

Thyroid-preserving laryngectomy should be advocated in carefully selected patients with advanced laryngeal carcinoma, as it reduces the incidence of hypothyroidism.

Hormonal Outcomes Following Hemithyroidectomy

OBJECTIVE

To assess hormonal outcomes and thyroid hormone (TH) replacement after hemithyroidectomy (HT).

STUDY DESIGN

Retrospective chart review.

SETTING

Quaternary care hospital system.

METHODS

A retrospective analysis was performed on patients who had an HT at Cleveland Clinic between 2000 and 2010 with outcomes assessed up to 5 years post-HT. Patients with overt hypothyroidism (OH; thyroid-stimulating hormone [TSH] >10 mIU/L, TSH >4.2 mIU/L on thyroid hormone [TH]), subclinical hypothyroidism (SH; TSH >4.2-10 mIU/L, no TH), or euthyroidism (EU; TSH 0.4-4.2 mIU/L, no TH) were compared. Patients with SH who returned to EU were compared to those who continued to have SH. For immediate start on TH, a receiver operating characteristic analysis was performed to determine dosage of TH above which suppression of TSH <0.4 mIU/L was predicted.

RESULTS

We identified 335 patients (average age 51 years, 78% female, median follow-up of 50 months). Of the 210 not immediately started on TH, 32.4% were OH, 13.3% were SH, and 54.3% were EU. EU patients were younger (48 years), had more remaining gland, were less likely to have lymphocytic infiltrate, and had a lower preoperative TSH (1.2 mIU/L). In the SH group, 58.3% of patients normalized their TSH. With immediate TH start, 45% developed suppressed TSH. Those on LT4 >1.05 mcg/kg/d were more likely to suppress (sensitivity 89%).

CONCLUSION

Most patients post-HT will remain EU, and immediate start of TH may lead to TSH suppression. Those with SH may ultimately normalize TSH. These findings together suggest that observation may be a better option than TH replacement after HT.

Prevalence of and risk factors for hypothyroidism after hemithyroidectomy: a systematic review and meta-analysis

PURPOSE

This systematic review and meta-analysis evaluated the prevalence of and risk factors for hypothyroidism following hemithyroidectomy as new evidence obtained in recent years warranted an update of previous meta-analyses.

METHODS

The PubMed, Embase, and Cochrane Library databases were searched through November 1, 2019, for articles examining the hypothyroidism prevalence and risk factors after lobectomy. The prevalence rate, risk ratio (RR), weighted mean difference (WMD) and standardized mean difference (SMD) were assessed by conducting a meta-analysis of proportions, binary variables, and continuous variables, respectively, using random-effects models.

RESULTS

Fifty-one studies showed a pooled risk of 29.9% (95% confidence interval (CI), 24.6-35.2%) for hypothyroidism following hemithyroidectomy. Risk factors for the development of postoperative hypothyroidism included the female sex (RR, 1.169; 95% CI, 1.040-1.314; P = 0.009), a higher preoperative thyrotropin (TSH) level (RR, 2.955; 95% CI, 2.399-3.640; P = 0.000), a lower preoperative FT4 level (SMD, -0.818; 95% CI, -1.623--0.013; P = 0.047), concomitant lymphocyte infiltration (RR, 1.558; 95% CI, 1.203-2.018; P = 0.001), Hashimoto's thyroiditis (HT) (RR, 1.480; 95% CI, 1.192-1.838; P = 0.000), a lighter weight of the remaining gland (WMD, -2.740; 95% CI, -3.708--1.772; P = 0.000), and a right side lobectomy (RR, 1.404; 95% CI, 1.075-1.835; P = 0.013).

CONCLUSIONS

Hypothyroidism is a significant complication after lobectomy, and appropriate and personalized surgical strategies should be designed after a careful preoperative assessment based on the estimated risk of hypothyroidism and risk factors.

Is hemithyroidectomy sufficient in unilateral benign nodular goitre?

BACKGROUND

Multinodular goiter is a common disease. If only one thyroid lobe is affected, hemithyroidectomy may be preferred to reduce complication and hormone replacement therapy. However, completion thyroidectomy may be required later. The aim of the study was to evaluate the role of completion thyroidectomy in patients who develop nodules after hemithyroidectomy, and we aimed to find the ratio of patients who required hormone replacement for permanent hypothyroidism.

METHODS

Patients who underwent hemithyroidectomy for benign nodular goitre between January 2012 and June 2017 were analyzed. The age of the patients, gender, number of nodules and dimension of the largest nodule, preoperative fine needle aspiration biopsy results, and postoperative histopathology findings were recorded. The need for completion thyroidectomy and need for postoperative L-thyroxine treatment were based on these parameters.

RESULTS

A total of 170 patients were included in the study. During the follow-up period new nodule or progression in existing nodule was observed in 23% (39 patients) of the cases. Permanent hypothyroidism requiring L-thyroxine treatment was observed in 31% (53 patients) of the cases. In this study, young age, multiple nodules and toxic nodular goitre diagnosis were noted to be independent risk factors that contributed to progression diseases in cases operated for benign nodular goitre.

CONCLUSIONS

Due to low reoperation risk and acceptable permanent hypothyroidism rates, hemithyroidectomy is a viable option for benign goitre cases. The patients should be on follow-up for possible complications, especially hypothyroidism, for at least a year.

Postoperative thyroid hormone supplementation rates following thyroid lobectomy

BACKGROUND

Thyroid lobectomy is performed for symptomatic benign nodules, indeterminate nodules, or low-risk well differentiated thyroid cancer. We aimed to determine factors associated with thyroid stimulating hormone over goal (TH) following lobectomy.

METHODS

We performed a retrospective single-institution cohort study of patients undergoing thyroid lobectomy from January 2016 to December 2017. TH was defined as need for thyroid hormone in accordance with guidelines. Univariate and multivariate logistic regression analysis was performed.

RESULTS

One hundred patients were included and 47% developed. TH: 73% of those with cancer, 38% with benign pathology (p = 0.002). Patients with TH were more likely to have thyroiditis 26% versus 3.8% (p = 0.002); higher preoperative TSH: mean 1.88mIU/L (SD 1.17) versus 1.16mIU/L (SD 0.77) (p = 0.0002), and smaller remnant thyroid lobe adjusted for body surface area 2.99ml/m2 versus 3.72ml/m2 (p = 0.003).

CONCLUSIONS

After thyroid lobectomy, TH is associated with preoperative TSH level, thyroiditis, remnant thyroid volume, and malignancy. The majority of patients with final pathology of carcinoma will require thyroid hormone supplementation to achieve TSH goal.

Postoperative thyroid hormone supplementation rates following thyroid lobectomy

BACKGROUND

Thyroid lobectomy is performed for symptomatic benign nodules, indeterminate nodules, or low-risk well-differentiated thyroid cancer. We aimed to determine factors associated with need for thyroid hormone supplementation following thyroid lobectomy.

METHODS

We performed a retrospective single-institution cohort study of patients undergoing thyroid lobectomy from January 2016 to December 2017. Thyroid hormone supplementation was assessed postoperatively based on guidelines for thyroid stimulating hormone (TSH) level goal for benign (0.5-4.5mIU/L) or malignant (<2mIU/L) final pathology. Univariate and multivariate logistic regression analysis was performed.

RESULTS

One hundred patients were included and overall 47% required thyroid hormone supplementation after thyroid lobectomy: 73% of those with cancer, 38% with benign pathology (p = 0.002). Patients requiring thyroid hormone supplementation were more likely to have thyroiditis 26% versus 3.8% of those who remained euthyroid (p = 0.002); have a higher preoperative TSH: mean 1.88mIU/L (SD 1.17) versus 1.16mIU/L (SD 0.77) (p = 0.0002), and have a smaller remnant thyroid lobe adjusted for body surface area 2.99ml/m2 versus 3.72ml/m2 (p = 0.003).

CONCLUSIONS

After thyroid lobectomy, the need for thyroid hormone supplementation is associated with higher preoperative TSH level, thyroiditis, remnant thyroid volume, and malignancy on final pathology. The majority of patients with final pathology of carcinoma will require thyroid hormone supplementation to achieve TSH goal. For patients with benign pathology after thyroid lobectomy the majority will not require thyroid hormone supplementation to achieve TSH goal.

The American Association of Endocrine Surgeons Guidelines for the Definitive Surgical Management of Thyroid Disease in Adults

OBJECTIVE

To develop evidence-based recommendations for safe, effective, and appropriate thyroidectomy.

BACKGROUND

Surgical management of thyroid disease has evolved considerably over several decades leading to variability in rendered care. Over 100,000 thyroid operations are performed annually in the US.

METHODS

The medical literature from 1/1/1985 to 11/9/2018 was reviewed by a panel of 19 experts in thyroid disorders representing multiple disciplines. The authors used the best available evidence to construct surgical management recommendations. Levels of evidence were determined using the American College of Physicians grading system, and management recommendations were discussed to consensus. Members of the American Association of Endocrine Surgeons reviewed and commented on preliminary drafts of the content.

RESULTS

These clinical guidelines analyze the indications for thyroidectomy as well as its definitions, technique, morbidity, and outcomes. Specific topics include Pathogenesis and Epidemiology, Initial Evaluation, Imaging, Fine Needle Aspiration Biopsy Diagnosis, Molecular Testing, Indications, Extent and Outcomes of Surgery, Preoperative Care, Initial Thyroidectomy, Perioperative Tissue Diagnosis, Nodal Dissection, Concurrent Parathyroidectomy, Hyperthyroid Conditions, Goiter, Adjuncts and Approaches to Thyroidectomy, Laryngology, Familial Thyroid Cancer, Postoperative Care and Complications, Cancer Management, and Reoperation.

CONCLUSIONS

Evidence-based guidelines were created to assist clinicians in the optimal surgical management of thyroid disease.

African Head and Neck Society Clinical Practice guidelines for thyroid nodules and cancer in developing countries and limited resource settings

BACKGROUND

International thyroid nodule and cancer management guidelines generally fail to take into account potential limitations in diagnostic and treatment resources.

METHODS

Thyroid cancer specialists from the African Head and Neck Society and American Head & Neck Society Endocrine Section developed guidelines for diagnosis and management of thyroid nodules and cancer in low resource settings. Recommendations were based on literature review and expert opinion, with level of evidence defined.

RESULTS

Using the ADAPTE process, diagnostic and treatment algorithms were adapted from the National Comprehensive Cancer Network (NCCN). Low resource settings were simulated by systematically removing elements such as availability of laboratory testing, hormone replacement, imaging, and cytopathology from NCCN guidelines.

CONCLUSIONS

Successful management of thyroid nodules and cancer in low resource settings requires adaptation of treatment methodologies. These guidelines define specific scenarios where either more or less aggressive intervention for thyroid pathology may be advisable based on limited available resources.

Oncological impact of hypothyroidism and levothyroxine supplementation following hemithyroidectomy in patients with papillary thyroid carcinoma

BACKGROUND

We aimed to evaluate the oncological impact of hypothyroidism and levothyroxine (LT) supplementation after hemithyroidectomy in patients with papillary thyroid carcinoma (PTC).

METHODS

We retrospectively examined 401 patients who underwent hemithyroidectomy for classic PTC and who were postoperatively followed-up with ≥3 thyroid function measurements for ≥24 months.

RESULTS

During 77.4 months of follow-up, 268/401 patients (66.8%) developed hypothyroidism and 19/401 patients (4.7%) showed recurrence. Recurrence rates did not differ between the euthyroidism and hypothyroidism development groups. Recurrence rates were significantly lower in the LT group than in the no-LT group, although mean postoperative thyroid-stimulating hormone (TSH) levels were not different between the two groups. Univariate and multivariate analysis showed that tumors sized >1 cm and lack of LT supplementation were significantly associated with recurrence.

CONCLUSIONS

Postoperative hypothyroidism development was not a risk factor for PTC recurrence after hemithyroidectomy. Nevertheless, LT supplementation reduced recurrence risk without suppressing TSH.

Usefulness of 1-year of thyroid stimulating hormone suppression on additional levothyroxine in patients who underwent hemithyroidectomy with papillary thyroid microcarcinoma

Background

The purpose of this study was to identify usefulness of 1-year of thyroid stimulating hormone (TSH) suppression, on additional levothyroxine in patients who underwent hemithyroidectomy with papillary thyroid microcarcinoma (PTMC).

Methods

Two-hundred consecutive patients who had received hemithyroidectomy February 2011 to March 2013, were enrolled, retrospectively. Group 1, only, was taking levothyroxine for a year, postoperatively. We evaluated postoperative hypothyroidism through serum TSH level, measured periodically.

Results

Postoperative TSH >10 was significantly different, at 13% and 25%, between two groups (P=0.036). Twenty patients in group 1, and 32 patients in group 2, received additional levothyroxine. Multivariate analysis showed that 1-year suppression, clinical thyroiditis, and preoperative TSH >2, were significantly associated with additional levothyroxine (OR 2.17, P=0.025 and OR 2.00, P=0.046 and OR 2.64, P=0.006). Too, 1-year TSH suppression, preoperative TSH >2, were also significantly associated with postoperative TSH >10 (OR 2.55, P=0.022 and OR 2.22, P=0.048).

Conclusions

We suggest 1-year TSH suppression after hemithyroidectomy, for PTMC in patients with preoperative TSH >2 mU/L and clinical thyroiditis, to reduce additional levothyroxine.

Levothyroxine Supplementation Following Hemithyroidectomy: Incidence, Risk Factors, and Characteristics

BACKGROUND

The goal of the present study was to determine the actual incidence, predictive risk factors, and clinical characteristics of levothyroxine supplementation (LT4S) used for the management of hypothyroidism after hemithyroidectomy.

METHODS

From 2008 to 2015, we included 535 patients who underwent hemithyroidectomy. LT4S was initiated based on three major criteria: the development of overt hypothyroidism, subclinical hypothyroidism with thyroid-stimulating hormone (TSH) levels > 10 mIU/L, or subclinical hypothyroidism with TSH levels of 4.5-10 mIU/L with associated signs/symptoms.

RESULTS

During the 69-month follow-up period, 321 patients (60%) developed overall hypothyroidism following hemithyroidectomy, and 141 ultimately required LT4S, with an overall LT4S incidence of 26.4%. The most common cause of LT4S initiation was subclinical hypothyroidism with TSH levels > 10 mIU/L. In 141 patients with LT4S, the mean maintenance dose of levothyroxine was 1.34 μg/kg, and only 6 patients (4.3%) discontinued LT4S during the follow-up. The 1-, 3-, 5-, and 7-year LT4S-free survival rates of 535 patients were 88.6%, 80.2%, 73.8%, and 69.1%, respectively. Preoperative TSH levels > 2.12 mIU/L and coexistence of Hashimoto's thyroiditis were significantly associated with LT4S following hemithyroidectomy. The risk of LT4S increased by 1.401 times, as preoperative TSH levels increased by 1 mIU/L.

DISCUSSION

A quarter of patients required LT4S after hemithyroidectomy for the management of hypothyroidism, with a mean maintenance levothyroxine dose of 1.34 μg/kg. The preoperative TSH level and coexistence of Hashimoto's thyroiditis were significant predictive factors of LT4S following hemithyroidectomy.

Risk-oriented concept of treatment for intrathyroid papillary thyroid cancer

Adapting treatment and follow-up according to the risk of recurrence and/or death from thyroid cancer is a relatively recent concept of "personnalized" medicine, developed particularly to avoid overtreatment of low-risk thyroid cancer which represents the majority of thyroid cancers diagnosed in the world today. For low-risk thyroid cancer, this decrease in extent of treatment involves the extent of surgery-total thyroidectomy, lobectomy or no surgery with active surveillance-but also the indications, doses and methods of stimulation when or if administering radioactive iodine (RAI), the indication for suppressive thyroxin therapy and the extent and modalities for follow-up that should be adapted to the risk of recurrence. The aim is to optimize medical resources and quality of life, particularly for low-risk patients whose life expectancy is that of the general population.

FACTORS INFLUENCING THE SUCCESSFUL MAINTENANCE OF EUTHYROIDISM AFTER LOBECTOMY IN PATIENTS WITH PAPILLARY THYROID MICROCARCINOMA: A SINGLE-CENTER STUDY

Objective: This study aimed to evaluate factors influencing the successful maintenance of postoperative euthyroidism in patients who did not undergo immediate thyroid hormone replacement after lobectomy for papillary thyroid microcarcinoma (PTMC). Methods: From September 2015 to June 2017, 186 patients underwent lobectomy for PTMC in our hospital. Patients taking medications for hypothyroidism and hyperthyroidism before and after lobectomy were excluded. Multiple parameters, including sex, age, pre-operative free thyroxine (T4), thyroid-stimulating hormone (TSH), thyroglobulin (TG), and thyroid autoantibody levels, body mass index (BMI), postoperative histopathology of the thyroid gland, remnant thyroid gland volume, and session number of levothyroxine discontinuation were retrospectively evaluated. These factors were compared between groups based on the maintenance of postoperative euthyroidism. Results: In 88 of the 175 patients (50.3%), postoperative euthyroidism was successfully maintained without thyroid hormone replacement during the first year after lobectomy. There were significant differences in sex (P = .003), pre-operative TSH levels (P = .002), and histopathology of the thyroid gland (P = .035) between the groups showing maintenance success and failure. The group showing successful maintenance had a higher percentage of male patients, lower levels of pre-operative TSH, and normal parenchymal histology of the thyroid gland. However, there were no significant between-group differences in age, pre-operative free T4, TG, and thyroid autoantibody levels, BMI, remnant thyroid gland volume, and session number of levothyroxine discontinuation. Conclusion: Patient sex, pre-operative TSH levels, and histopathology of the thyroid gland may influence the maintenance of postoperative euthyroidism after lobectomy. Abbreviations: BMI = body mass index; PTMC = papillary thyroid microcarcinoma; RR = reference range; T4 = thyroxine; TFT = thyroid function test; TG = thyroglobulin; TSH = thyroid-stimulating hormone.

Post-hemithyroidectomy hypothyroidism in non autoimmune thyroiditis patients: Incidence, risk factors and duration of follow up

BACKGROUND

Hemithyroidectomy has a known but less predictable sequelae of hypothyroidism. Presence of anti-thyroid antibody is known, well studied risk factor. Other postulated risk factors include higher pre-operative TSH level and lower ratio of post-operative thyroid remnant to the patient's weight. We reviewed our data to address the above mentioned risk factors.

METHOD

This was a retrospective study done in National Cheng Kung University Hospital, Taiwan from 2015 to 2017. 125 patients underwent hemithyroidectomy, but 24 patients were excluded due to autoimmune thyroiditis, which was determined as the exclusion criteria. Standard panel of blood investigations were taken in each clinic visit before and after operation. A neck ultrasound was done 2 months post-operatively to assess the thyroid remnant. Chi-square test was used for categorical data analysis. Independent student t-test was used for continuous data with parametric distribution and Mann-Whitney U test for non parametric data. p < 0.05 was taken as statistically significant.

RESULT

The mean duration of follow up was 29.3 months. 4 out of 101 patients had clinical hypothyroidism; 23 patients developed subclinical hypothyroidism post-hemithyroidectomy. 6 patients of subclinical hypothyroidism had spontaneously recovered within 1 year. Pre-operative TSH >2.0 uIU/mL was a risk factor as Chi square test showed p < 0.001. However, thyroid remnants were found not to be a risk factor with the Mann-Whitney U test of p = 0.928.

CONCLUSION

Minimum 1 year of follow up for hemithyroidectomy patients was suggested in order not to miss patients developing hypothyroidism post-operatively.

Management of Subclinical and Overt Hypothyroidism Following Hemithyroidectomy in Children and Adolescents: A Pilot Study

Background: To reduce surgical complications and avoid lifelong thyroid hormone replacement, hemithyroidectomy is preferred in children and adolescents with benign nodular thyroid disease. However, hypothyroidism following hemithyroidectomy may occur, and postoperative thyroid hormone replacement for hypothyroidism following hemithyroidectomy is usually administered without a full understanding of the clinical characteristics of hypothyroidism. Methods: To investigate the incidence and risk factors of hypothyroidism after hemithyroidectomy in children and adolescents, and to identify whether postoperative thyroid hormone replacement is necessary, a retrospective review of 43 patients under 18 years of age who underwent hemithyroidectomy from January 2009 to October 2016 was conducted. All hypothyroid patients were retrospectively analyzed to determine the incidence and predisposing factor(s) of postoperative hypothyroidism. All patients were measured regarding age, sex, serum thyrotropin (TSH), anti-thyroid antibody, and histological evidence of lymphocytic infiltration. Hypothyroid patients were measured for symptoms, timing of diagnosis, and thyroid hormone replacement. Results: The mean age at the time of surgery was 13.65 ± 3.04 years. Of the cohort, 34 patients were female (79.07%), and the mean follow-up time was 28 ± 9 months. Hypothyroidism was diagnosed in 11 of the 43 patients. The mean postoperative TSH level was 7.17 ± 2.13 μIU/ml. The mean preoperative TSH level was 3.11 ± 0.59 μIU/ml in hypothyroid patients compared with 1.92 ± 0.72 μIU/ml in euthyroid patients (P < 0.05). A preoperative TSH level >2.2 μIU/l and lymphocytic infiltration graded 3 or 4 were found to be independent risk factors for the development of hypothyroidism. There were no significant differences between groups in terms of patient age or sex. Conclusions: In the pediatric and adolescent population, patients with elevated preoperative TSH levels or the presence of lymphocytic infiltration may increase the risk of risk of hypothyroidism. In our study, postoperative levothyroxine (L-T4) treatment was necessary in 16.28% of cases after hemithyroidectomy. Patients with mild postoperative hypothyroidism should be followed up, without the need for immediate L-T4 replacement, so as to expect patients to recover spontaneously.

Microwave ablation induces a lower systemic stress response in patients than open surgery for treatment of benign thyroid nodules

OBJECTIVE

In this study, we compared the systemic stress response induced by microwave ablation with that induced by conventional open surgery for treatment of benign thyroid nodules.

METHODS

A total of 108 patients with benign thyroid nodules were randomly assigned to receive ultrasound-guided thyroid microwave ablation (microwave group, n = 57) and conventional open thyroid surgery (open group, n = 51). Body temperature, white blood cell (WBC) counts, visual analogue scale (VAS) scores for pain, and serum levels of high sensitive C-reactive protein (hs-CRP), interleukin 6 (IL-6) and cortisol were measured at 24 h before operation and at 8 h, 24 h and 48 h after operation.

RESULTS

No significant between-group differences were observed with respect to preoperative body temperature, VAS scores, WBC counts, serum hs-CRP, IL-6 and cortisol levels. Patients in the open group exhibited higher body temperature at 24 h after operation and higher WBC counts at both 24 h and 48 h after operation, as compared to those in the microwave group. As compared with microwave ablation, open surgery was associated with significantly higher VAS scores, and significantly higher serum levels of hs-CRP, IL-6 and cortisol at all postoperative time-points (8 h, 24 h and 48 h).

CONCLUSION

Microwave ablation induces a lower systemic stress response than open surgery for treatment of benign thyroid nodules.

Controversies in the Management of Low-Risk Differentiated Thyroid Cancer

Controversy exists over optimal management of low-risk differentiated thyroid cancer. This controversy occurs in all aspects of management, including surgery, use of radioactive iodine for remnant ablation, thyroid hormone supplementation, and long-term surveillance. Limited and conflicting data, treatment paradigm shifts, and differences in physician perceptions contribute to the controversy. This lack of physician consensus results in wide variation in patient care, with some patients at risk for over- or undertreatment. To reduce patient harm and unnecessary worry, there is a need to design and implement studies to address current knowledge gaps.

Clinical Features of Early and Late Postoperative Hypothyroidism After Lobectomy

CONTEXT

Lobectomy is preferred in thyroid cancer to decrease surgical complications and avoid lifelong thyroid-hormone replacement. However, postoperative hypothyroidism, requiring thyroid-hormone replacement, may occur.

OBJECTIVE

We aimed to identify the incidence and risk factors of postoperative hypothyroidism to develop a surveillance strategy after lobectomy for papillary thyroid microcarcinoma (PTMC).

METHODS

This historical cohort study involved 335 patients with PTMC treated by lobectomy. Postoperative thyroid functions were measured regularly, and patients were prescribed levothyroxine according to specific criteria. Patients not satisfying hormone-replacement criteria were closely followed up.

RESULTS

Postoperative hypothyroidism occurred in 215 patients (64.2%) including 5 (1.5%) with overt hypothyroidism and 210 (62.7%) with subclinical hypothyroidism. Forty patients (11.9%) were required thyroid hormone replacement. One hundred nineteen patients (33.5%) experienced temporary hypothyroidism and spontaneously recovered to euthyroid state. High preoperative thyroid-stimulating hormone (TSH) was the most important factor predicting postoperative hypothyroidism and failure of recover from hypothyroidism (odds ratio [OR], 2.82 and 1.77; 95% confidence interval [CI], 2.07 to 3.95 and 1.22 to 2.63; P < 0.001 and 0.002, respectively). Of the 215 patients eventually developing postoperative hypothyroidism, 70 (32.6%) developed hypothyroidism after the first postoperative year. Postoperative 1-year TSH levels were able to differentiate patients developing late hypothyroidism or euthyroidism (OR, 2.29; 95% CI, 1.68 to 3.26; P < 0.001).

CONCLUSIONS

Preoperative and postoperative TSH levels might be predictive for patients who develop postlobectomy hypothyroidism and identify those requiring long-term surveillance for hypothyroidism. Additionally, mild postoperative hypothyroidism cases should be followed up without immediate levothyroxine replacement with the expectation of spontaneous recovery.

Lateral habenula as a link between thyroid and serotoninergic system modiates depressive symptoms in hypothyroidism rats

Depression-like behavior is observed in both rats and people with hypothyroidism, which suggests that altered thyroid hormone levels are closely associated with mental illness. Furthermore, decreased serotonin (5-hydroxytryptamine, 5-HT) levels are found in some brain regions of hypothyroid rats with depression-like behavior. However, the mechanism underlying the effects of hypothyroidism on the central serotonin system is unclear. The lateral habenula (LHb) is related to both the serotonin and thyroid systems and also plays an important role in the pathogenesis of depression. Our study aimed to disclose the role of the LHb in the onset of depression-like behavior in thyroidectomy (TD) rats. Forced swimming (FST) and open-field tests (OFT) were performed to measure behavioral changes in TD rats. The expression of β calmodulin-dependent protein kinase type II (β CaMKII) in the LHb, cytochrome C oxidase (COX) activity in the LHb and dorsal raphe nucleus (DRN), and 5-HT levels in the DRN were assayed. We found that TD rats exhibited depression-like behavior in the FST and OFT. Compared with the sham group, neural activity and the expression of β CaMKII in TD rats were higher in the LHb, and neural activity and 5-HT levels were lower in the DRN. Depressive behavior and decreased 5-HT levels in the DRN in TD rats were reversed by LHb lesioning. Our study indicates that depression-like behavior in TD rats can be attributed to decreased 5-HT levels in the DRN resulting from inhibition by an overactive LHb. The LHb mediates the effect of the thyroid system on 5-HT function in the DRN.

The Effect of Levothyroxine Discontinuation Timing on Postoperative Hypothyroidism after Hemithyroidectomy for Papillary Thyroid Microcarcinoma

Objective. No previous studies regarding the appropriate timing of thyroid hormone discontinuation after hemithyroidectomy have been published. This study aimed to identify the appropriate timing for levothyroxine discontinuation after hemithyroidectomy among patients with papillary thyroid microcarcinoma (PTMC). Methods. This study retrospectively evaluated 304 patients who underwent ≥1 attempt to discontinue levothyroxine after hemithyroidectomy for treating PTMC between January 2008 and December 2013. Fifty-three patients were excluded because of preoperative hypothyroidism or hyperthyroidism, a history of thyroid hormone or antithyroid therapy, no available serological data, or a postoperative follow-up of <24 months. We evaluated the associations of successful levothyroxine discontinuation with patient age, sex, preoperative serological data, underlying thyroid gland histopathology, anteroposterior diameter of the residual thyroid gland, number of discontinuation attempts, and initial discontinuation timing. Results. Among the 251 included patients, 125 patients (49.8%) achieved successful levothyroxine discontinuation during the follow-up period after hemithyroidectomy. There was a significant difference in the outcomes for patients who underwent an initial discontinuation attempt at ≤3 months and ≥4 months after hemithyroidectomy (p < 0.001). There were significant differences in the discontinuation outcomes according to underlying thyroid histopathology (p = 0.001), preoperative thyroid-stimulating hormone levels (p < 0.001), and number of discontinuation attempts (p < 0.001). Conclusions. Among patients with PTMC, the initial levothyroxine discontinuation attempt is recommended at ≥4 months after hemithyroidectomy.

Prospective analysis of risk for hypothyroidism after hemithyroidectomy

Objectives. To evaluate risk factors and to develop a simple scoring system to grade the risk of postoperative hypothyroidism (PH). Methods. In a controlled prospective study, 109 patients, who underwent hemithyroidectomy for a benign thyroid disease, were followed up for 12 months. The relation between clinical data and PH was analyzed for significance. A risk scoring system based on significant risk factors and clinical implications was developed. Results. The significant risk factors of PH were higher TSH (thyroid-stimulating hormone) level and lower ratio of the remaining thyroid weight to the patient's weight (derived weight index). Based on the log of risk factor, preoperative TSH level greater than 1.4 mU/L was assigned 2 points; 1 point was for 0.8-1.4 mU/L. The derived weight index lower than 0.8 g/kg was assigned 1 point. A risk scoring system was calculated by summing the scores. The incidences of PH were 7.3%, 30.4%, and 69.2% according to the risk scores of 0-1, 2, and 3. Conclusion. Risk factors for PH are higher preoperative TSH level and lower derived weight index. Our developed risk scoring system is a valid and reliable tool to identify patients who are at risk for PH before surgery.

Factors associated with postoperative hypothyroidism after lobectomy in papillary thyroid microcarcinoma patients

PURPOSE

No previous study regarding the correlation between post-operative thyroid function and underlying thyroid histopathology has been published. This study assessed the relationship between postoperative thyroid function after lobectomy and multiple factors in papillary thyroid microcarcinoma (PTMC) patients.

MATERIALS AND METHODS

From January 2010 to December 2010, 338 patients who had undergone thyroid lobectomy for PTMC were enrolled. Patients with pre-operative hyperthyroidism or those with hypothyroidism but no pre-operative serological data were excluded, leaving a cohort of 285 patients. The relationships between post-operative thyroid function (based on successful cessation of thyroxine replacement therapy) and multiple factors (patient age and sex, serological data, the Pre-operative anteroposterior diameter of the thyroid gland, underlying histopathology of the thyroid gland, and number of attempts to stop thyroxine replacement therapy) were analyzed.

RESULTS

Out of 285 patients, 157 attempted to stop thyroxine replacement therapy once or twice after lobectomy; 91 successfully stopped thyroxine replacement therapy during the study period. The final histopathologic diagnoses after surgery included Hashimoto's thyroiditis (n = 5), non-Hashimoto type of lymphocytic thyroiditis (n = 17), and normal thyroid parenchyma (n = 135). Pre-operative thyroid-stimulating hormone (TSH) levels differed significantly between patients with postoperative hypothyroidism and those with postoperative euthyroidism (univariate logistic regression analysis, p = 0.0028; multivariate logistic regression analysis, p = 0.0029). No statistically significant differences were found for any other factors.

CONCLUSIONS

The study results demonstrated that the Pre-operative TSH level was the only predictor for the development of post-operative hypothyroidism after thyroid lobectomy in PTMC patients.

Prediction of thyroid hormone supplementation after thyroid lobectomy

BACKGROUND

Thyroid function, as assessed by thyroid-stimulating hormone (TSH) levels, was evaluated in patients after thyroid lobectomy. These assessments were analyzed against perioperative measurements to determine if any of these preoperative values were predictive of postoperative hypothyroidism and the need for postoperative levothyroxine treatment.

METHODS

In a retrospective study, data from 276 thyroid lobectomy patients were examined. These surgeries occurred over the period from January 2003-December 2012. Age, sex, volume of resected thyroid, thyroiditis, preoperative free T4, TSH, and microsomal antibody levels were analyzed for correlation with postoperative levothyroxine supplementation.

RESULTS

The overall percentage of the patients taking postoperative levothyroxine was 23.6%. The preoperative TSH level showed strong correlation with TSH levels measured 1-mo postoperatively (P < 0.001). Preoperative TSH levels >2.5 mIU/L and positive microsomal antibody showed significant correlation with postoperative levothyroxine supplementation (P < 0.001; relative risk, 8.933, and 3.438, respectively). By stratifying the patients based on preoperative TSH levels and presence of microsomal antibodies, in the low-risk group with TSH <2.5 mIU/L and negative microsomal antibody, 7% of patients received postoperative levothyroxine replacement but in the high-risk group with TSH >2.5 mIU/L and positive microsomal antibody, 77.8% required levothyroxine replacement (P < 0.001).

CONCLUSIONS

The most significant preoperative predictors for levothyroxine supplementation are preoperative TSH level and presence of microsomal antibodies. Patients with preoperative TSH <2.5 mIU/L showed a low risk of requiring postoperative levothyroxine supplementation.

Radiofrequency ablation compared to surgery for the treatment of benign thyroid nodules

Objective. Benign thyroid nodules are a common occurrence whose only remedy, in case of symptoms, has always been surgery until the advent of new techniques, such as radiofrequency ablation (RFA). This study aimed at evaluating RFA efficacy, tolerability, and costs and comparing them to hemithyroidectomy for the treatment of benign thyroid nodules. Design and Methods. 37 patients who underwent RFA were retrospectively compared to 74 patients surgically treated, either in a standard inpatient or in a short-stay surgical regimen. Efficacy, tolerability, and costs were compared. The contribution of final pathology was also taken into account. Results. RFA reduced nodular volume by 70% after 12 months and it was an effective method for treating nodule-related clinical problems, but it was not as effective as surgery for the treatment of hot nodules. RFA and surgery were both safe, although RFA had less complications and pain was rare. RFA costed €1,661.50, surgery costed €4,556.30, and short-stay surgery costed €4,139.40 per patient. RFA, however, did not allow for any pathologic analysis of the nodules, which, in 6 patients who had undergone surgery (8%), revealed that the nodules harboured malignant cells. Conclusions. RFA might transform our approach to benign thyroid nodules.