Effects of Central Neck Dissection on Complications in Differentiated Thyroid Cancer

Predictive factors for permanent hypoparathyroidism following total thyroidectomy: A retrospective cohort study of 5,671 cases

OBJECTIVE

To evaluate the rates of permanent hypoparathyroidism based on demographic variables, patient comorbidities, clinical staging of the disease, surgery performed, and severity of transient hypoparathyroidism.

SUBJECTS AND METHODS

This is a retrospective cohort study with patients who underwent total thyroidectomy with or without neck dissection between January 2014 and December 2021.

RESULTS

5,671 patients were analyzed, 966 (17)%) presented transient hypoparathyroidism and 106 (1.8%) developed permanent hypoparathyroidism. The logistic regression model analyzing the cohort of patients with transient hypoparathyroidism demonstrates that the number of dissected lymph nodes from the central compartment, immediate postoperative PTH levels, the necessity of postoperative intravenous (IV) calcium supplementation and the duration of IV calcium supplementation are significant predictors. When applied to the original dataset, this model presents a NPV of 1.0000 and a PPV of 0.9594 with an overall accuracy of 0.9624.

CONCLUSION

The incidence of permanent hypoparathyroidism was closely associated with the extent of level VI dissection, particularly regarding the number of lymph nodes removed and whether the dissection was bilateral. Furthermore, the severity of post-operative hypocalcemia was demonstrated by the decrease in PTH levels, as well as the need for and duration of intravenous calcium supplementation.

BRAF V600E positive papillary thyroid carcinoma (TERT and TP53 mutation coexistence excluded): Correlation of clinicopathological features and the extent of surgical treatment and its complications

INTRODUCTION

Papillary thyroid carcinoma (PTC) frequently harbors the BRAF V600E mutation. Recent research suggests that aggressive behavior in BRAF V600E+ PTC may be due to an undetected mutation in the TERT gene. This study aims to observe the clinicopathological features of BRAF V600+ PTC and correlate them with surgical treatment complications.

METHODS

A retrospective analysis was conducted on the BRAF V600E+ PTC cohort from July 2019 to January 2023. The histopathological features and surgical treatment (total thyroidectomy - group A, total thyroidectomy + central block neck dissection - group B) complications were correlated. Patients with TERT and TP53 mutation were excluded. Next-generation sequencing and real-time PCR were used for genetic analysis.

RESULTS

Out of 121 PTCs, 65 cases showed BRAF V600E mutation with the following features: intracapsular spread (13.8%), extracapsular spread (27.7%), extrathyroidal spread (15.4%), multifocality (26.2%), angioinvasion (12.3%), and local metastasis (27.7%). The incidence of surgical complications in group A/B was: reversible recurrent laryngeal nerve (RLN) paresis 3.7/7.1%, RLN paresis permanent 0/2.4%, paresthesia 6.8/23.8%, hypocalcemia 36.4/61.9% on day 1 and 27.3/33.3% on day 3, and bleeding 2.3/9.5%. There was no significant difference in clinicopathological features between the BRAF V600E+ and BRAF V600E- PTC groups. Group B had a significantly higher incidence of hypoacalcaemia on postoperative day 1 (p = 0.047).

CONCLUSION

The BRAF V600E mutation will certainly remain important in the preoperative diagnosis of PTC. The more radical surgical procedures currently recommended may be abandoned in the future, particularly elective CLND, which has a higher risk of postoperative complications.

Risk Factors for Transient and Permanent Hypoparathyroidism Following Thyroidectomy: A Comprehensive Review

Hypoparathyroidism is a common complication following thyroidectomy, resulting in significant disturbances in calcium homeostasis due to low parathyroid hormone (PTH) levels. This comprehensive review examines the risk factors associated with transient and permanent hypoparathyroidism post-thyroidectomy, emphasizing surgical, patient-related, and perioperative factors. Transient hypoparathyroidism, characterized by temporary hypocalcemia resolving within weeks to months, is often managed with short-term calcium and vitamin D supplementation. In contrast, permanent hypoparathyroidism persists beyond six months post-surgery, necessitating lifelong supplementation and potentially PTH replacement therapy. The review delves into the anatomy and physiology of the parathyroid glands, mechanisms leading to hypoparathyroidism, and incidence rates. Surgical factors such as the extent of thyroidectomy, surgeon expertise, and intraoperative parathyroid gland preservation are critical in determining the risk of hypoparathyroidism. Patient factors, including age, sex, pre-existing conditions, and perioperative management, influence outcomes. Diagnostic and monitoring strategies, along with management protocols for both transient and permanent hypoparathyroidism, are discussed. Prevention strategies, emerging research, future surgical techniques, and intraoperative monitoring directions are highlighted to improve clinical outcomes. This review aims to enhance understanding, inform surgical practices, and optimize postoperative care to minimize the incidence and impact of hypoparathyroidism in thyroidectomy patients.

Early Dynamic Risk Stratification Decreases Rate of Ablative and Adjuvant Radioiodine Use in ATA Low and Intermediate Risk Papillary Thyroid Cancer Patients

Objectives

In differentiated thyroid cancer (DTC), radioiodine (RAI) therapy is most frequently employed for remnant ablation or as adjuvant therapy for the remaining disease. The application of RAI to patients classified as intermediate risk (InR) is still a matter of debate. The aim of this study is to analyze the effect of early postoperative risk assessment on RAI use on papillary thyroid cancer patients who are classified as low risk (LoR) or InR.

Methods

This is a single-center, prospective registry study. One-hundred-eighty-six patients operated between January 2012 and August 2021 and categorized as LoR or InR were included in this study. All patients had total thyroidectomy and central lymph node dissection by the same endocrine surgeon. An early dynamic risk assessment (EDRA) consisting of neck ultrasonography, serum thyroglobulin (Tg) and anti-Tg levels was performed 6 weeks after surgery. Most of the patients were either followed up without RAI or received ablative low activity (30-50 mCi) RAI based on predetermined criteria.

Results

Median follow-up was 63 months. Sixty-six (61%) patients in the LoR group and 43 (56%) patients in the InR group did not receive RAI treatment. Thirty-eight (35%) and 22 (29%) patients in LoR and InR groups received ablative (30-50 mCi) RAI therapy, respectively. In LoR group 5 (4.6%) patients and in InR group 12 (16%) patients received 100 mCi or more RAI activity. Only one patient in the InR group recurred during follow-up. No statistically significant difference regarding local recurrence was found between patients who didn't receive RAI or were treated with RAI within both LoR (p=0.152) and InR (p=0.272) groups.

Conclusion

There is consensus for LoR patients about omitting RAI therapy after surgery. Indications for RAI treatment in InR DTC are still under debate. RAI use based on EDRA seems to be a better option than decisions solely made on histopathological risk factors and decreases adjuvant high-activity RAI use without increasing recurrence risk.

Assessing Parathyroid Gland Viability and Predicting Postoperative Hypoparathyroidism in Thyroid Surgery: The Utility of Indocyanine Green Angiography

Objectives

Postoperative hypoparathyroidism is a common complication following thyroidectomy, with the potential for significant morbidity and cost. While various techniques have been proposed for intraoperative parathyroid gland (PG) identification and preservation, indocyanine green (ICG) angiography has emerged as a promising method. In this retrospective study, patients who underwent total thyroidectomy with or without central neck dissection were evaluated for the utility of ICG angiography in identifying PGs and the correlation of ICG scores with postoperative parathyroid function.

Methods

ICG angiography was performed using a standardized protocol, and the degree of PG vascularization was assessed visually. A scoring system was employed based on ICG uptake intensity in PGs, as described in the literature. Pearson's correlation test examined the relationship between the total ICG score and percentage parathyroid hormone (PTH) gradient, postoperative calcium, and PTH levels. In addition, patients with at least one well-vascularized PG were also evaluated.

Results

Twenty-two patients were included in the study. Significant positive correlations were found between the total ICG score and postoperative PTH levels (r=0.549, p=0.008), and a negative correlation with the percentage of PTH gradient (r=-0.504, p=0.01). However, six patients with well-vascularized PGs on ICG angiography still developed postoperative hypoparathyroidism.

Conclusion

ICG angiography offers a potential tool for evaluating PG vascularization during thyroidectomy and predicting the risk of postoperative hypoparathyroidism. However, its application should be used judiciously, and the technique should be improved for PG preservation. Further studies are warranted to better understand its benefits and limitations in thyroid surgery.

Differentiated Thyroid Cancer in Children and Adolescents: Clinicopathological Characteristics of 32 Patients Followed up in our Pediatric Endocrinology Unit

Objectives

This study aims to investigate the clinical and pathological features of patients with differentiated thyroid cancer (DTC) treated at our tertiary care institution.

Methods

Thirty-two children and adolescents followed up with the diagnosis of DTC between 2001 and 2017 were enrolled. We classified patients with DTC into two groups as below and above 10 years of age, and compared their clinical and pathological features.

Results

The mean age at presentation was 11.2±4 years. The female/male ratio was 7 (28:4). The diagnosis was papillary thyroid cancer (PTC) in 90.6% (n=29). The frequencies of lymph node and pulmonary metastases were 53.1% and 21.8%, respectively. The groups were comparable in terms of gender, initial clinical signs and tumor histopathology. The mean tumor size was greater in the younger age group (p=0.008). However, there was no difference between the two groups in terms of lymph node and pulmonary metastases. The pathological parameters associated with tumor aggressiveness were also similar between the groups, except lymphovascular invasion. Lymphovascular invasion was more frequent in the younger age group (p=0.01). Patients with lymph node and pulmonary metastases were more likely to have extrathyroidal extension and lymphovascular invasion.

Conclusion

PTC was the most common type of DTC and presented with considerable rates of lymph node and pulmonary metastases. Tumor size was greater and lymphovascular invasion was more common in younger patients. Overall prognosis was favorable despite high rates of lymph node and pulmonary metastases.

Genetic Changes in Thyroid Cancers and the Importance of Their Preoperative Detection in Relation to the General Treatment and Determination of the Extent of Surgical Intervention—A Review

Carcinomas of the thyroid gland are some of the most common malignancies of the endocrine system. The causes of tumor transformation are genetic changes in genes encoding cell signaling pathways that lead to an imbalance between cell proliferation and apoptosis. Some mutations have been associated with increased tumor aggressiveness, metastatic lymph node spread, tendency to dedifferentiate, and/or reduced efficiency of radioiodine therapy. The main known genetic causes of thyroid cancer include point mutations in the BRAF, RAS, TERT, RET, and TP53 genes and the fusion genes RET/PTC, PAX8/PPAR-γ, and NTRK. Molecular genetic testing of the fine needle aspiration cytology of the thyroid tissue in the preoperative period or of the removed thyroid tissue in the postoperative period is becoming more and more common in selected institutions. Positive detection of genetic changes, thus, becomes a diagnostic and prognostic factor and a factor that determines the extent of the surgical and nonsurgical treatment. The findings of genetic research on thyroid cancer are now beginning to be applied to clinical practice. In preoperative molecular diagnostics, the aggressiveness of cancers with the most frequently occurring mutations is correlated with the extent of the planned surgical treatment (radicality of surgery, neck dissection, etc.). However, clear algorithms are not established for the majority of genetic alterations. This review aims to provide a basic overview of the findings of the most commonly occurring gene mutations in thyroid cancer and to discuss the current recommendations on the extent of surgical and biological treatment concerning preoperatively detected genetic changes.

Toluidine blue for the detection of sentinel lymph nodes in patients with thyroid cancer

Introduction

Thyroid cancer (TC) demonstrates steady growth in incidence worldwide and remains an urgent problem in oncology. The detection of sentinel lymph nodes (SLN) with a selective dye and further histological examination in selecting the proper (personalized) surgical strategy and the volume of surgical intervention for clinically undetermined regional lymph nodes. The purpose of the study is to evaluate the effectiveness and safety of intraoperative detection of SLN with a 1% toluidine blue aqueous solution.

Material and methods

The significant tasks are to identify the pattern of TC metastases to cervical lymph nodes, to establish the prevalence of "skip" metastases, to compare the frequency of complications after total thyroidectomy and central neck dissection and lateral neck dissection with total thyroidectomy and central neck dissection, and to determine the feasibility of the application of lateral neck dissections in patients with papillary and follicular TC without metastases to regional lymph nodes (according to physical examination and ultrasound).

Results

According to our data the SLN identification rate was 97.6%. Sensitivity, specificity, positive predictive value, negative predictive value, and frequency of false negative and false positive results was 89.2, 94.6, 88.03, 95.16, 10.8, and 5.4%, respectively. The most common metastasis was in the central neck compartment (83.7%). Skip metastases were determined in 4.9% of patients.

Conclusions

The low prevalence of "skip" metastases and a significant risk of postoperative complications (wound exudation, lymphorrhagia, inflammation, hypoparathyroidism, paresis of the vocal cords) support the idea that lateral neck dissection is appropriate only in cases of confirmed metastases by physical examination and/or ultrasound at the preoperative stage.