Microwave ablation of symptomatic benign thyroid nodules: Short- and long-term effects on thyroid function tests, thyroglobulin and thyroid autoantibodies

Thyroid Dysfunction Following Thermal Ablation of Large Solid and Solid-Predominant Thyroid Nodules

OBJECTIVES

Thermal ablation (TA) is an alternative to lobectomy for thyroid nodules (TNs). While it is believed that thyroid function remains stable after TA for cystic TNs, the impact of TA on solid TNs, especially the large ones, is less explored. This study investigates changes in thyroid hormones after TA in patients with solid-predominant TNs and identifies potential risk factors for thyroid dysfunction after TA.

METHODS

Euthyroid patients with solid-predominant TNs (≥ 80% solid) were enrolled. The volume, diameter, and cytopathology of TNs were assessed before TA. TA was performed using either microwave or radiofrequency ablation. Thyroid hormone levels were measured at 1 week and 1, 3, 6, and 12 months after TA.

RESULTS

Seventy-seven euthyroid patients with TNs were included. The euthyroid rate dropped to 70.1% at 1 week after TA but improved to over 90% by 1 month and returned to 100% by 12 months. At 1 week after TA, subclinical hyperthyroidism and hyperthyroidism were observed, with elevated thyroxine, free triiodothyronine, free thyroxine, and thyroglobulin antibody levels, along with decreased thyroid-stimulating hormone (TSH) levels. The diameter and total volume of TNs were positively correlated with thyroid dysfunction, while TSH-baseline was negatively correlated with thyroid dysfunction 1 week after TA. A larger diameter and lower baseline TSH were identified as independent risk factors for thyroid dysfunction.

CONCLUSIONS

TA may cause short-term thyroid dysfunction, especially in patients with large TNs. Monitoring of thyroid hormone levels is recommended from 1 week to 3 months after TA to manage potential thyroid dysfunction effectively.

Graves' disease diagnosed nearly six months after microwave ablation of benign thyroid nodules: a case report

BACKGROUND

Microwave ablation is a new, minimally invasive technique for the treatment of thyroid nodules. Hyperthyroidism due to destructive thyroiditis is a known risk of microwave ablation, though it occurs in only a minority of cases. We report a rare case of a patient diagnosed with Graves' disease nearly six months after undergoing microwave ablation of a thyroid nodule.

CASE PRESENTATION

On July 31, 2022, a 43-year-old male patient presented to our hospital with symptoms of pyrexia, excessive sweating, and palpitations lasting for 15 days. History inquiry revealed that the patient had undergone microwave ablation of right-sided thyroid nodule nearly five months ago at another hospital. The patient's thyroid ultrasound suggested bilateral diffuse thyroid lesions, with a moderately echogenic mass observed on the right side of the thyroid gland, potentially indicative of thyroid nodule ablation. The patient had elevated serum thyroid hormone levels, decreased thyroid-stimulating hormone levels and positive associated thyroid antibodies. To control the symptoms of hyperthyroidism, the patient opted for oral antithyroid medication, and thyroid hormonal levels returned to normal after 3 months of treatment. The patient is now under regular follow-up.

CONCLUSIONS

In this case, we presented the onset of Graves' disease following microwave ablation in a patient with subclinical thyroid autoimmunity. While the causal relationship between microwave ablation and Graves' disease remains unproven, this case suggests that preexisting autoimmune thyroid conditions may increase susceptibility to postoperative thyroid dysfunction. Procedural factors, such as thermal injury to surrounding tissues and potential involvement of the autonomic nervous system, are also potential contributors to the development of Graves' disease following microwave ablation.

Evaluation of the clinical efficacy of microwave ablation for benign thyroid nodules based on contrast-enhanced ultrasound

This study evaluates the clinical efficacy of microwave ablation in patients with benign thyroid nodules based on contrast-enhanced ultrasound. A total of 92 patients with benign thyroid nodules admitted to our hospital from January 2020 to December 2022 were selected as research subjects and divided into control group and observation group according to different treatment methods, with 46 cases in each group. All patients received microwave ablation. Imaging examination and monitoring were performed before and after microwave ablation. The control group underwent routine ultrasound examination, and the observation group underwent contrast-enhanced ultrasound examination. It was determined whether or not to terminate ablation therapy according to the imaging examination results. Results of enhanced MRI were used as the gold standard to evaluate the clinical efficacy, thyroid nodule volume, thyroid nodule volume reduction rate, nodule recurrence, and complication rate of the 2 groups. Using the results of enhanced MRI as the gold standard, the total ablation rate of observation group was 96.55%, which was significantly higher than that of control group 85.96%, and the nodule survival rate of 3.45% was significantly lower than that of control group 14.04% (P < .05). After 1 month, 3 months, 6 months, and 12 months, the thyroid nodule volume of both groups was significantly reduced, and the thyroid nodule volume of observation group was significantly smaller than that of control group (P < .05). After 1 month, 3 months, 6 months, and 12 months, the reduction rate of thyroid nodule volume in 2 groups was significantly increased, and the reduction rate of thyroid nodule volume in observation group was significantly higher than that in control group (P < .05). After treatment, the recurrence rate of nodule in observation group was 4.35%, which was significantly lower than that in control group, 15.22% (P < .05). After treatment, the complication rate of observation group was 8.70%, which was significantly lower than that of control group 26.09% (P < .05). Contrast-enhanced ultrasound can effectively monitor the treatment range of benign thyroid nodules by microwave ablation, improve clinical efficacy, reduce the recurrence rate of nodules, and has high effectiveness and safety.

Efficacy and safety of percutaneous ultrasound-guided thermal ablation in the treatment of cervical metastatic lymph nodes from papillary thyroid carcinoma

OBJECTIVE

To evaluate the efficacy and safety of percutaneous ultrasound-guided thermal ablation in the treatment of cervical metastatic lymph nodes (LNs) from papillary thyroid carcinoma (PTC).

MATERIALS AND METHODS

A total of 77 patients with 79 LNs ablated by microwave ablation (MWA) or radiofrequency ablation (RFA) between September 2018 and October 2022 were enrolled in this study. After treatment, patients were followed up with measurement of diameters of LNs and serum thyroglobulin (s-Tg) at 1, 3, 6, and 12 months and annually thereafter. The paired t-test was used to compare the changes of s-Tg level, diameters of LNs before and after ablation.

RESULTS

There were no serious complications related to ablation while one case of incomplete ablation in MWA was found during follow-up. The mean longest and shortest diameter of the ablated LNs reduced from 11.6 ± 4.3 mm to 5.0 ± 4.1 mm (p < 0.001), and from 6.1 ± 1.9 mm to 3.0 ± 2.5 mm (p < 0.001) at the last follow-up visit. Besides, the final volume reduction rate (VRR) was 61.8 ± 56.4% (range, -67.0 -100%). The complete disappearance rate was 46.8%, but there were 4 (5.1%) LNs becoming bigger than before. The average s-Tg level was 9.2 ± 26.6 ng/mL, a data significantly decreased to 3.7 ± 7.0 ng/mL at the last follow-up, but no statistical difference was shown.

CONCLUSION

Thermal ablation is an effective and safe modality for the treatment of metastatic LNs from PTC.

Uncooled Microwave Ablation as a Treatment Option to Preserve Thyroid Function in Patients with Benign Thyroid Nodules

Objective:

The objective is to evaluate the long-term efficacy and safety of uncooled MWA for the treatment of benign thyroid nodules and its long-term effect on thyroid functions.

Material and Methods:

The study was conducted on 40 patients with 40 nodules. They were treated between September 2019 and December 2020. Nodules’ volumes, thyroid functions (triiodothyronine, free thyroxine, thyrotropin) and anti-thyroid peroxidase and anti-thyroglobulin antibodies were measured before treatment and at 3rd, 6th and 12th month following the treatment. Volume reduction rates and changes in clinical findings were evaluated.

Results:

The mean volume reduction rate was 49.88, 65.3, and 79.06% at 3rd, 6th, and 12th month, respectively. Antibody levels and thyroid function tests have remained within normal limits and were not exhibited significant change during follow-ups (p > 0.05), except for a significant increase in free thyroxin level at 12th-month (p = 0.007). Subjective symptoms and cosmetic scores were significantly improved all follow-up (p < 0.0001). The only complication was a first-degree skin burn in a patient.

Conclusion:

In conclusion, uncooled microwave ablation is an effective and safe method for the treatment of benign thyroid nodules and preserves thyroid function.

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.

Ultrasound-Guided Thermal Ablation of Thyroid Nodules: Technicalities Progress and Clinical Applications, Especially in Malignant Thyroid Nodules

Thyroid nodules are commonly encountered in health care practice. They are usually benign in nature, with few cases being malignant, and their detection has increased in the adult population with the help of ultrasonography. Thyroidectomy or surgery is the first-line treatment and traditional method for thyroid nodules; however, thyroidectomy leaves permanent scars and requires long-term use of levothyroxine after surgery, which makes patients more reticent to accept this treatment. Thermal ablation is a minimally-invasive technique that have been employed in the treatment of benign and malignant thyroid nodules nodules, and have been shown to be effective and safe. Several studies, including long-term, retrospective, and prospective studies, have investigated the use of ablation to treat benign thyroid nodules and malignant thyroid nodules, including papillary thyroid carcinoma. Here, we review the recent progress in thermal ablation techniques for treating benign and malignant nodules, including their technicalities, clinical applications, pitfalls and limitations, and factors that could affect treatment outcomes. Special in-depth elaboration on the recent progress of the application of thermal ablation therapy in malignant thyroid nodules.

Conspicuousness and recurrence related factors of ultrasound-guided microwave ablation in the treatment of benign thyroid nodules

OBJECTIVE

Microwave ablation (MWA) is a minimally invasive technique for the treatment of benign thyroid nodules. The purpose of this study was to evaluate efficacy and safety of ultrasound-guided MWA in the treatment of benign thyroid nodules, and to find out the recurrence related factors, so as to provide reference for future clinical work.

METHODS

This study retrospectively analyzed the patients who received ultrasound-guided MWA for benign thyroid nodules in our hospital from October 2018 to March 2020. A total of 214 patients were included in the study. We assessed thyroid volume changes (represented by volume reduction ratio VRR), the energy per 1 mL reduction in nodular volume (represented by energy volume ratio ΔE), the serum levels of free triiodide thyroid hormone (FT3), free thyroxine (FT4), thyrotropin (TSH) and complications after MWA treatment.

RESULTS

There were a total of 306 nodules in 214 patients, including 183 (85.51%) females and 31 (14.49%) males. The median diameter and volume of the nodule were 33 mm and 8.01 mL. The VRR at 1 month, 3 months, 6 months and 12 months were 40.79%, 60.37%, 74.59% and 85.60%, respectively. In addition, MWA had a better ablation effect for small nodules (initial volume ≤ 10 mL). In recurrent studies, we found that ΔE was an independent risk factor for benign thyroid nodules (P < 0.05).

CONCLUSIONS

Ultrasound-guided MWA is effective and safe in the treatment of benign thyroid nodules. In addition, it has little damage to surrounding tissues and no effect on thyroid function. Especially, the nodules with smaller initial volume, the treatment is better. On the other hand, the energy per 1 mL reduction ΔE in nodular volume may be associated with nodular recurrence, which requires further follow-up for longer periods. At this stage, we consider that ultrasound-guided MWA can be used as one of the main clinical treatment methods for benign thyroid nodules.