Comparison of outcomes between hemithyroidectomy alone and hemithyroidectomy with elective unilateral central neck dissection in patients with papillary thyroid microcarcinoma

A cohort study of microwave ablation and surgery for low-risk papillary thyroid microcarcinoma

BACKGROUND

The optimal treatment method for papillary thyroid microcarcinoma (PTMC) is lacking consensus. Here we aimed to compare the efficacy and safety of surgery and microwave ablation (MWA) for PTMC.

METHODS

The clinical data of 644 patients with PTMC treated between July 2013 and June 2020 were retrospectively analyzed. A total of 320 and 324 patients underwent MWA and surgery, respectively. We observed lesion changes in the MWA group and compared the recurrence, metastasis, complications, and other health economic indicators between the 2 groups.

RESULTS

The mean follow-up time was 890.7 ± 532.9 (187.9-2679.0) days in the MWA group and 910.9 ± 568.4 (193.8-2821.5) days in the surgery group. In the MWA group, lesion volume increased significantly after ablation and then gradually decreased. The final lesion volume reduction rate was 90.73% ± 7.94%, and 193 lesions (60.3%) disappeared completely. There were no significant intergroup differences in recurrence or metastasis. The incidence of main complications (temporary hypothyroidism, hypoparathyroidism, and temporary hoarseness) was significantly lower in the MWA group than in the surgery group (p < 0.001). The treatment time, intraoperative blood loss, and hospital stay were significantly lower in the MWA group than in the surgery group (p < 0.001).

CONCLUSIONS

MWA is effective for treating PTMC, with a low incidence of complications and less trauma. The rates of post-treatment recurrence and metastasis are similar to those of surgery, indicating that MWA is a suitable alternative to surgery.

US-guided Microwave Ablation of Low-Risk Papillary Thyroid Microcarcinoma: Longer-Term Results of a Prospective Study

BACKGROUND

Papillary thyroid microcarcinoma (PTMC) has become a main cause of the extremely high incidence of thyroid carcinoma. This study aimed to evaluate the longer-term effectiveness of ultrasound (US)-guided microwave ablation (MWA) for treatment of low-risk PTMC with a large population.

METHODS

This prospective study was approved by ethics committee of our institution. MWA was performed under US-guidance for 119 unifocal PTMC patients without clinically cervical or distant metastasis. The target ablation zone exceeded the tumor edge judged by contrast-enhanced US to avoid marginal residue and recurrence. US and thyroid function evaluation were followed at 1, 3, 6, and 12 months after treatment and every 6 to 12 months thereafter. Any adverse event associated with MWA was evaluated.

RESULTS

The follow-up duration after MWA was 37.2 ± 20.9 months (range 12-101 months). Tumor volume decreased significantly from 1.87 ± 1.03 mL immediately after MWA to 0.01 ± 0.04 mL at the final evaluation (P < 0.001), with a mean volume reduction ratio of 99.4 ± 2.2% and 107 cases (93.9%) got complete remission. A patient was detected with cervical lymph node metastasis at 26-month follow-up and underwent 1 additional MWA treatment successfully. No distant metastasis was observed. All the acquired histological pathology results confirmed the absence of residual or recurrent tumor cells after MWA. No delayed complications associated with MWA were encountered for all patients.

CONCLUSIONS

Percutaneous MWA is technically feasible for complete PTMC destruction and showed well longer-term effectiveness; thus, it seems to be an effective nonsurgical therapy to complement the current recommendation for selected low-risk PTMC patients.

Impact of prophylactic unilateral central neck dissection needed for patients with papillary thyroid microcarcinoma

Background

Papillary thyroid microcarcinoma (PTMC), the increase in the diagnosis of which has led to an overall rise in the diagnostic rate of thyroid malignancies, is generally managed through a reduction in the surgical extent. Nevertheless, a considerable number of patients with PTMC experience subclinical central lymph node (LN) metastases following prophylactic central neck dissection (CND). This study aimed to investigate the impact of prophylactic CND on locoregional recurrence in PTMC patients who underwent hemithyroidectomy.

Methods

We reviewed the medical records of 1,071 patients with clinically LN-negative PTMC who underwent hemithyroidectomy between 2004 and 2012. Cox proportional hazards regression analysis was performed to investigate the predictive factors for recurrence. The median follow-up duration was 79 months (range, 12-176 months).

Results

Totally, 613 patients underwent hemithyroidectomy only, whereas 458 underwent hemithyroidectomy plus prophylactic unilateral CND. Recurrence was observed in 27 patients (eight and 19 patients in the prophylactic and non-prophylactic CND groups, respectively). Patients with a tumor size ≤6 mm (hazard ratio, 2.927; 95% confidence interval, 1.372-6.245; P=0.005) had favorable recurrence-free survival (RFS); however, there was no relationship between prophylactic unilateral CND and RFS.

Conclusions

The incidence of locoregional recurrence was low in patients with PTMC who underwent hemithyroidectomy. In addition, prophylactic unilateral CND performance was not associated with RFS in PTMC. Accordingly, the use of prophylactic unilateral CND for clinically LN-negative PTMC should be avoided.

The Effect of Prophylactic Central Neck Dissection During Hemithyroidectomy on Locoregional Recurrence in Patients With Papillary Thyroid Carcinoma: A Meta-Analysis

Objectives.

Hemithyroidectomy is commonly performed in patients with low- to intermediate-risk papillary thyroid carcinoma. The purpose of this meta-analysis was to evaluate the effect of prophylactic central neck dissection on locoregional recurrence in patients undergoing hemithyroidectomy.

Methods.

A meta-analysis was performed of full-text publications published in English retrieved from the Embase database.

Results.

The rate of regional recurrence in the central compartment after hemithyroidectomy, with or without prophylactic central neck dissection, was 0.17% and 1.78%, respectively. This difference was statistically significant. Recurrence in the lateral compartment or contralateral thyroid was not affected by prophylactic central neck dissection; the overall rate of recurrence was 1.3% and 5.4%, respectively.

Conclusion.

Prophylactic central neck dissection significantly reduced the risk of recurrence in the central compartment in patients undergoing hemithyroidectomy.

Recurrence following hemithyroidectomy in patients with low- and intermediate-risk papillary thyroid carcinoma

BACKGROUND

This study evaluated the incidence, patterns and risk factors for recurrence after hemithyroidectomy in patients with low- and intermediate-risk papillary thyroid carcinoma (PTC), and verified the predictive role of the risk staging systems in current use.

METHODS

The clinicopathological characteristics and risk categories were analysed according to recurrence in patients who underwent hemithyroidectomy for low- and intermediate-risk conventional PTC, and were followed up for at least 24 months. Five risk staging systems were used to stratify risk: the 2015 American Thyroid Association (ATA) system; Age, Metastases, Extent and Size (AMES) system; Metastases, Age, Complete resection, Invasion and Size (MACIS) system; Grade, Age, Metastases, Extent and Size (GAMES) system; and the eighth AJCC system.

RESULTS

The study included 561 patients; 93·9 per cent of the study population (527 of 561) had a papillary thyroid microcarcinoma 1 cm or smaller in size. At a mean follow-up of 83 months, 25 patients (4·5 per cent) had recurrence; among these patients, 23 (92%) presented with a remaining thyroid lobe. Multifocality was significantly associated with recurrence in univariable and multivariable analyses (adjusted hazard ratio 3·16, 95 per cent c.i. 1·25 to 7·98; P = 0·015). Disease-free survival (DFS) varied according to multifocality (P = 0·010). The five risk staging systems were not associated with recurrence, and their Harrell's C-index ranged from 0·500 to 0·531. DFS rates did not differ between the risk categories in each system.

CONCLUSION

Although the recurrence rate after hemithyroidectomy in patients with low- and intermediate-risk PTC was low, meticulous follow-up focusing on the remaining thyroid lobe is needed for early detection and timely management of recurrence. The risk scoring systems in current use have no predictive role in these patients.

Ultrasound-guided laser ablation versus surgery for solitary papillary thyroid microcarcinoma: a retrospective study

Objectives: To compare the clinical outcomes of ultrasound-guided laser ablation (LA) and surgery for treatment of solitary papillary thyroid microcarcinoma (PTMC). Methods: A total of 81 consecutive patients with solitary PTMC were included in this retrospective study. Among them, 36 received LA and 45 underwent surgery. Surgery was performed by hemithyroidectomy with unilateral central neck dissection. The follow-up consisted of a physical examination, neck ultrasonography, chest X-ray or CT scan and thyroid function tests. The procedure time, hospital stay, complication and recurrence rates were compared between the two groups after treatment. Results: The follow-up period for the LA and surgical group were 49.2 ± 4.5 months (range, 30-54 months) and 48.5 ± 6.2 months (range, 24-54 months), respectively. The mean hospital stay and procedure time in the LA group were shorter than those in the surgical group. After LA, the largest diameter and average volume decreased from 4.7 ± 1.4 mm to 0.2 ± 0.8 mm, and from 43.2 ± 38.8 mm³ to 0.7 ± 4.1 mm³ (p < .05 for both), respectively. The complication rates and recurrence rates did not differ between the LA group (2.8% [1 of 36] and 5.6% [2 of 36]) and the surgical group (6.7% [3 of 45] and 6.7% [3 of 45]) (p > .05 for both). No distant metastasis occurred in the either group during the follow-up period. Conclusions: Compared with hemithyroidectomy with unilateral central neck dissection, ultrasound-guided LA was also a safe and effective therapy for treating solitary PTMC, and it may be considered as a treatment alternative for patients who are ineligible or refusal to undergo surgery.

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.

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.