Prophylactic Central Neck Dissection for cN1b Papillary Thyroid Carcinoma: A Systematic Review and Meta-Analysis

BackgroundThe value of prophylactic central neck dissection (PCND) for papillary thyroid carcinoma (PTC) with clinically evident lateral cervical lymph node metastases (cN1b) remains unclear. Therefore, a systematic review and meta-analysis was conducted to assess the efficacy and safety of PCND.MethodsA comprehensive systematic search was conducted on PubMed, Web of Science, Cochrane library and Embase databases up to September 2021 to identify eligible studies. Controlled clinical trials assessing therapeutic effects and safety of PCND for cN1b PTC patients were included. The risk of bias for each cohort study was assessed using the Newcastle-Ottawa Scale (NOS). The primary outcomes were indexes related to the locoregional recurrence (LRR) and surgical complications. Review Manager software V5.4.0 was used for statistical analysis. A fixed effects model was adopted for the data without heterogeneity, otherwise a random effects model was used.ResultsWe included 4 retrospective cohort studies, which comprised 483 PTC patients. There was no statistically significant difference in the central neck recurrence (CNR) (10.2% vs. 3.8%, relative risk (RR) = 1.82; 95%CI 0.90–3.67; P = 0.09), lateral neck recurrence (LNR) (5.1% vs. 7.7%, RR = 0.47; 95% CI 0.13–1.74; P = 0.26), and overall recurrence (OR) (18.9% vs. 16.9%, RR = 0.77; 95%CI 0.34–1.76; P = 0.54), between LND + PCND group and LND group. Simultaneously, PCND increased the risk of permanent hypoparathyroidism (11.4% vs. 4.5%, RR = 2.70, 95%CI 1.05–6.94; P = 0.04) and overall complications (17.0% vs. 5.3%, RR = 3.28; 95%CI 1.37–7.86; P = 0.008).ConclusionsThis meta-analysis showed that PCND did not have any advantage in preventing LRR for cN1b PTC. Meanwhile, PCND may result in the increased rate of surgical complications. However, the current evidence is limited and more clinical trials are still needed to further clarify the true role of PCND.Systematic Review Registrationhttps://www.crd.york.ac.uk/PROSPERO/, CRD42021281825.

Utility of sentinel lymph node biopsy in papillary thyroid microcarcinoma

Purpose: There are many studies on sentinel lymph node (SLN) biopsy in thyroid carcinoma but SLN biopsy (SLNB) in papillary thyroid carcinoma (PTC) remains open to debate. Therefore in this retrospective study, the usefulness of SLNB in thyroid carcinoma patients who had micro-PTC without cervical lymphadenopathy was assessed.Methods: SLNB was performed in 114 patients who were diagnosed with micro-PTC in a single lobe without palpable or ultrasound-detected lymph node at the tertiary center between January 2012 and December 2013. After SLNB, all patients underwent total thyroidectomy and central neck dissection or thyroid lobectomy and central neck dissection of the single side.Results: SLNs were identified in 112 of 114 patients with 41 positive SLNs and 71 negative SLNs on intraoperative frozen sections. However, eight negative patients were found to be positive in the final pathology. Sentinel node identification rate and false negative value of SLNB were 98.2% and 11.3%, respectively. In the univariate analysis, higher lymph node metastasis was detected in men than in women. Higher detection number of SLN showed higher probability of lymph node metastasis.Conclusion: SLNB may be helpful in papillary thyroid cancer, especially in male patients. Also, it is useful for the staging of nodal status and clearance of persistent disease.

Case Report: Transoral Endoscopic Thyroidectomy via Vestibular Approach in Pediatric Thyroid Cancer

Background: Transoral endoscopic thyroidectomy via vestibular approach (TOETVA) is a new technique that has become more popular worldwide because of its many advantages. However, this novel approach for thyroid cancer treatment in children is highly challenging, even for high-volume surgeons. In our study, we report our experiences with TOETVA for pediatric patients with thyroid cancer.Patients and Methods: This study included four pediatric patients who underwent TOETVA performed by a single surgeon between June and December 2020. Patient demographics and surgical outcomes including operative time, incidence of complications, and length of hospital stay were evaluated.Results: Four patients successfully underwent TOETVA with no complications. All patients were girls, aged from 13 to 18. Three patients underwent lobectomy and isthmusectomy, plus prophylactic unilateral central neck dissection. One patient had a total thyroidectomy, plus prophylactic bilateral central neck dissection. The mean operative time was 85 min for the lobectomy and 120 min for total thyroidectomy plus central neck dissection. The median hospital stay was 4.1 days. No drains were used. The histological examination showed four cases of malignant disease (papillary thyroid carcinoma). The mean number of harvested lymph nodes was 4.2 (ranged 3 to 8).Conclusion: In the hands of a high-volume surgeon, TOETVA is a novel, feasible, and safe approach for treating selected pediatric patients with thyroid cancer.

Clinical and morphological factors that increase the risk of locoregional metastasis of papillary thyroid cancer

Background. The sensitivity of the ultrasound method to determine lymph node metastases of papillary thyroid cancer (PTC) to the central lymphatic collector of the neck at the preoperative stage is low, 49 % only, therefore assessment of the factors leading to the prolongation of the process is of great importance in the development of surgical treatment tactics.Aim — to evaluate factors that increase the risk of locoregional metastases of papillary thyroid cancer and substantiate the advisability of systematic central neck dissection (SCND).Materials and methods. A retro-prospective single center study of the risk of PTC prolongation in the form of locoregional metastases (LRM) was carried out. The data of 514 patients operated for papillary thyroid disease were processed. The main group included 240 patients in whom LRM was found according to the results of histopathological examination (HPE), control group consisted of 274 patients without LRMsigns. The following signs were taken into account: multifocal lesions of the thyroid gland, the patients’age, gender, presence of thyroiditis, the size of the dominant tumor, invasion of adipose tissue. In order to substantiate the expediency of the SCND, retrospective processing of the data of 514 patients, operated from 2018 to 2020, was carried out for PTC, in which the presence of metastases was not cytologically confirmed at the preoperative stage (cN0).Results. The mean age of patients of the main group was lower than in the control group (p < 0.001). The median size of the primary tumor in patients of the main group was significantly higher than in the control group (p < 0.001). The men portion in the main group was significantly higher than in the control group, and the part of women vice versa (p < 0.05). Invasion of the tumor into the adipose tissue in the main group occurred almost twice as often (p < 0.01). The number of patients with multifocal lesions in both groups was practically the same and did not differ statistically (p > 0.05). Ipsilateral and contralateral localization of tumors in both groups did not differ significantly (p > 0.05). The presence of thyroiditis in the control group was higher than in the main group (p < 0.05). The diagnostic efficiency (DE) of accounting for the factor of invasion into adipose tissue was 64.8 %, tumor size over 1.3 cm — 66.7 %, age up to 47 years — 60.0 %. The frequency of detecting metastases with cN0 at the preoperative stage, according to HPE results, was 25.8 %.Conclusions. The reliability of preoperative imaging and diagnostic methods does not allow to ignore the likelihood of LRM and not perform SCND. According to the obtained data, in 25.8 % of casesmetastases were verified based on HPE owing to thesystematic central neck dissection. Male gender (p < 0.01), age of patients (p < 0.001), size of primary tumor (p < 0.001), invasion of adipose tissue (p < 0.01) can serve as predictors of the increased LRMPTC risk. The presence of invasion of adipose tissue (diagnostic efficacy 64.8 %), tumor size more than 1.3 cm (66.7 % DE) and age < 47 (60.0 % DE) increased the risk of LRMPTC. The presence of thyroiditis (the frequency of thyroiditis exposure in control group was higher than in the main group (p < 0.05)), contralateral lesions of the thyroid gland (p > 0.05), multifocal lesions (p > 0.05) cannot serve as reliable prognostic factors for the increased LRMrisk.