Comparison of Ultrasound-Guided Percutaneous Polidocanol Injection Versus Percutaneous Ethanol Injection for Treatment of Benign Cystic Thyroid Nodules

Assessing the relative effectiveness of various ultrasound-guided ablation techniques for treating benign thyroid nodules: A systematic review and network meta-analysis

BACKGROUND

Benign thyroid nodules (BTNs) represent a prevalent clinical challenge globally, with various ultrasound-guided ablation techniques developed for their management. Despite the availability of these methods, a comprehensive evaluation to identify the most effective technique remains absent. This study endeavors to bridge this knowledge gap through a network meta-analysis (NMA), aiming to enhance the understanding of the comparative effectiveness of different ultrasound-guided ablation methods in treating BTNs.

METHODS

We comprehensively searched PubMed, Embase, Cochrane, Web of Science, Ovid, SCOPUS, and ProQuest for studies involving 16 ablation methods, control groups, and head-to-head trials. NMA was utilized to evaluate methods based on the percentage change in nodule volume, symptom score, and cosmetic score. This study is registered in INPLASY (registration number 202260061).

RESULTS

Among 35 eligible studies involving 5655 patients, NMA indicated that RFA2 (radiofrequency ablation, 2 sessions) exhibited the best outcomes at 6 months for percentage change in BTN volume (SUCRA value 74.6), closely followed by RFA (SUCRA value 73.7). At 12 months, RFA was identified as the most effective (SUCRA value 81.3). Subgroup analysis showed RFA2 as the most effective for solid nodule volume reduction at 6 months (SUCRA value 75.6), and polidocanol ablation for cystic nodules (SUCRA value 66.5).

CONCLUSION

Various ablation methods are effective in treating BTNs, with RFA showing notable advantages. RFA with 2 sessions is particularly optimal for solid BTNs, while polidocanol ablation stands out for cystic nodules.

Thyroid ultrasound and its ancillary techniques

Ultrasound (US) of the thyroid has been used as a diagnostic tool since the late 1960s. US is the most important imaging tool for diagnosing thyroid disease. In the majority of cases a correct diagnosis can already be made in synopsis of the sonographic together with clinical findings and basal thyroid hormone parameters. However, the characterization of thyroid nodules by US remains challenging. The introduction of Thyroid Imaging Reporting and Data Systems (TIRADSs) has improved diagnostic accuracy of thyroid cancer significantly. Newer techniques such as elastography, superb microvascular imaging (SMI), contrast enhanced ultrasound (CEUS) and multiparametric ultrasound (MPUS) expand diagnostic options and tools further. In addition, the use of artificial intelligence (AI) is a promising tool to improve and simplify diagnostics of thyroid nodules and there is evidence that AI can exceed the performance of humans. Combining different US techniques with the introduction of new software, the use of AI, FNB as well as molecular markers might pave the way for a completely new area of diagnostic accuracy in thyroid disease. Finally, interventional ultrasound using US-guided thermal ablation (TA) procedures are increasingly proposed as therapy options for benign as well as malignant thyroid diseases.

[Ultrasound-guided ablation techniques for thyroid lesions]

Ultrasound-guided ablation techniques have been increasingly introduced into routine treatment of thyroid lesions as a complement to existing surgical therapies and radioiodine treatment. In cystic or predominantly cystic lesions instillation therapy (ethanol/polidocanol ablation) has yielded good results. Novel thermal ablation techniques, including radiofrequency ablation (RFA), microwave ablation (MWA), laser ablation (LA) and high intensity focused ultrasound (HIFU), induce irreversible cellular effects by locally applying temperatures ≥ 60 °C to the targeted thyroid region. Lesions causing local symptoms or focal hyperfunctionality can thus be selectively treated under continuous sonographic monitoring. While a considerable body of evidence supports the efficacy and safety of various local ablative techniques, future challenges lie in initiating comparative prospective trials and in standardizing clinical practice, training and continuous quality assessment on a regional and superregional level. In the future, it shall be indicated to include local ablative techniques - so far not known to all patients in Germany - into the informed decision-making process as a suitable alternative or supplement to existing therapies.

Efficacy Assessment and Analysis of Related Factors of Ultrasound-Guided Percutaneous Lauromacrogol Injection for Cystic Thyroid Nodules

OBJECTIVES

This study aimed to investigate the factors influencing the short-term and long-term efficacy of sclerotherapy for cystic thyroid nodules.

METHODS

Ninety-nine cystic thyroid nodules that underwent ultrasound-guided fine-needle aspiration biopsy, detection of thyroglobulin in fine needle aspirate (Tg-FNA), and ultrasound-guided percutaneous lauromacrogol injection were retrospectively enrolled from July 2018 to July 2021. All nodules were followed up at 3 and 12 months after the procedure. Factors related to lauromacrogol injection efficacy, including initial volume, vascularity, pathological types, and Tg-FNA level, were analyzed. The nodules were classified as non-effective (VRR <50%) and effective groups (VRR ≥50%) at 3 months to evaluate short-term prognosis, and non-cured (VRR <90%) and cured groups (VRR ≥90%) at 12 months to evaluate long-term prognosis.

RESULTS

The volume of cystic thyroid nodules tended to shrink during follow-up. The resolution rate was 79.80% (79/99) at 3 months and 96.91% (94/97) at 12 months. The cure rate was 80.41% (78/97) at 12 months. Independent factors for the long-term prognosis included Tg-FNA level and vascularity (P  < .05). Only Tg-FNA level was an independent factor for the short-term prognosis (P  < .05). The area under the receiver operating characteristic curve for assessing the efficacy at 3 months was 0.79 (95% confidence interval [CI]: 0.65-0.89). With a cutoff value of Tg-FNA 126.92 ng/mL, the specificity was 0.70, and the sensitivity was 0.85.

CONCLUSIONS

Ultrasound-guided percutaneous lauromacrogol injection is an effective treatment option for cystic thyroid nodules. It is less effective in viscous or vascular predominantly cystic nodules.

Approach to FNA of Thyroid Gland Cysts

Fine needle aspiration is a well-known procedure for the diagnosis and management of thyroid lesions, representing the first diagnostic tool for the definition of their nature. In clinical practice, a thyroid nodule can be classified as solid, cystic, and partially cystic based on its internal components. Different thyroid imaging reporting systems and cytologic diagnostic systems have focused their attention on solid nodules, which are more frequently linked with a malignant outcome. In fact, numerous papers demonstrated that nodules with microcalcifications, a taller-than-wide shape, hypoechogeneity, and irregular margins, are more likely to be malignant on histology. Nevertheless, according to the literature, the risk of malignancy in a partially cystic thyroid nodule ranges between 3.3 and 17-5%, including, for instance, the possible diagnosis of a cystic papillary thyroid carcinoma and other malignant entities. Therefore, in the current review article, we are going to discuss the approach to thyroid cystic lesions on fine needle aspiration cytology.

Long-term efficacy and safety of percutaneous ethanol injection (PEI) in cystic thyroid nodules: A systematic review and meta-analysis

BACKGROUND

Percutaneous ethanol injection (PEI) is used for the treatment of benign cystic thyroid nodules. This systematic review and meta-analysis aimed to obtain strong evidence of its long-term efficacy and safety.

METHODS

PubMed, CENTRAL, Scopus and Web of Science databases were searched until November 2020 for studies reporting data on volume reduction rate (VRR), compressive symptoms and cosmetic concerns. Associated complications were assessed. A random-effects model was designed to pool the data.

RESULTS

Out of 385 papers, nine studies evaluating 1667 nodules were finally included. Overall, VRR at 6, 12, 24, 36, 60 and 120 months was 77%, 81%, 72%, 68%, 74% and 69%, respectively. Significant reductions in the compressive symptoms and cosmetic concerns were observed. No permanent complications were observed.

CONCLUSIONS

The present meta-analysis showed that PEI could significantly reduce the volume of benign cystic thyroid nodules. This reduction was already effective at 6 months post-treatment, and the effect was stable over time.

Long-term efficacy evaluation of a protocol for the management of symptomatic thyroid cysts with ultrasound-guided percutaneous ethanol injection

AIM

To evaluate the long-term efficacy of percutaneous ethanol injection treatment (PEIT) as an alternative to thyroid surgery in symptomatic thyroid cysts.

PATIENTS AND METHODS

100 subjects (48±12 years; 58% women) with symptomatic thyroid cysts relapsing after drainage were prospectively included. PEIT was conducted using an established procedure, and the initial cyst volume, symptoms and pain perceived by the patient were assessed. The volume of instilled alcohol was ≤2ml without re-extraction in all cases. Patients were followed-up for more than 3 years and final cyst volume and symptom improvement were assessed.

RESULTS

Mean maximum cyst diameter before drainage was 3.1±1.2cm. In 71% of patients ≤2 PEIT sessions were required. Median maximum cyst volume was 12.7 (5.4-21.7)ml before the first drainage and median total volume extracted from the cysts was 13.0 (6.2-37.0)ml. After a mean follow-up period of 52±10 months, 98% of patients reported a complete absence of symptoms. The final median volume for the whole group was 0.8 (0.1-2.0)ml with a median volume reduction of 94 (81-99)%. A final volume reduction greater than 65% was observed in 90% of cases. Reported pain during the procedure was absent or mild in 76.4% of cases.

CONCLUSIONS

PEIT is a safe and well-tolerated first-line treatment for symptomatic thyroid cysts with long-term effectiveness.

Efficacy of Ethanol Ablation for Benign Thyroid Cysts and Predominantly Cystic Nodules: A Systematic Review and Meta-Analysis

BACKGROUND

Ultrasound-guided minimally invasive procedures are widely used to treat thyroid diseases. The objective of this study was to assess the efficacy and safety of ethanol ablation (EA) in comparison with other non-surgical options in the treatment of benign thyroid cystic nodules.

METHODS

We conducted a systematic search of studies on EA for thyroid cystic nodules, mainly in the Ovid-MEDLINE and Embase, Web of Science, and Cochrane databases. The standardized mean difference (SMD) of the volume reduction ratio (VRR) after EA versus other non-surgical treatments comprised the primary outcome, whereas the odds ratio (OR) of therapeutic success rates between the two groups comprised the secondary outcome.

RESULTS

The meta-analysis included 19 studies (four randomized controlled trials and 15 non-randomized studies) with 1,514 participants. The cumulative VRR of EA was 83.908% (95% confidence interval [CI], 79.358% to 88.457%). EA had a significantly higher pooled VRR (SMD, 0.381; 95% CI, 0.028 to 0.734; P=0.030), but not a significantly higher pooled therapeutic success rate (OR, 0.867; 95% CI, 0.132 to 5.689; P=0.880), than other forms of non-surgical management including radiofrequency ablation (RFA), polidocanol sclerotherapy, and simple aspiration with or without saline flush. However, the VRR and therapeutic success rate were not significantly different between EA and RFA. Major complications were recorded only in six patients (0.53%) with self-limiting dysphonia.

CONCLUSION

The role of EA as the first-line treatment for benign thyroid cysts and predominantly cystic nodules is supported by its high effectiveness and good safety profile compared to other currently available non-surgical options.

Long-term efficacy evaluation of a protocol for the management of symptomatic thyroid cysts with ultrasound-guided percutaneous ethanol injection

AIM

To evaluate the long-term efficacy of percutaneous ethanol injection treatment (PEIT) as an alternative to thyroid surgery in symptomatic thyroid cysts.

PATIENTS AND METHODS

100 subjects (48±12 years; 58% women) with symptomatic thyroid cysts relapsing after drainage were prospectively included. PEIT was conducted using an established procedure, and the initial cyst volume, symptoms and pain perceived by the patient were assessed. The volume of instilled alcohol was ≤2ml without re-extraction in all cases. Patients were followed-up for more than 3 years and final cyst volume and symptom improvement were assessed.

RESULTS

Mean maximum cyst diameter before drainage was 3.1±1.2cm. In 71% of patients ≤2 PEIT sessions were required. Median maximum cyst volume was 12.7 (5.4-21.7)ml before the first drainage and median total volume extracted from the cysts was 13.0 (6.2-37.0)ml. After a mean follow-up period of 52±10 months, 98% of patients reported a complete absence of symptoms. The final median volume for the whole group was 0.8 (0.1-2.0)ml with a median volume reduction of 94 (81-99)%. A final volume reduction greater than 65% was observed in 90% of cases. Reported pain during the procedure was absent or mild in 76.4% of cases.

CONCLUSIONS

PEIT is a safe and well-tolerated first-line treatment for symptomatic thyroid cysts with long-term effectiveness.

Sequential treatment by polidocanol and radiofrequency ablation of large benign partially cystic thyroid nodules with solid components: Efficacy and safety

PURPOSE

The purpose of this study was to retrospectively evaluate the efficacy and safety of a sequential treatment including percutaneous polidocanol sclerotherapy and radiofrequency ablation (RFA) in terms of volume reduction and complication rate in large, benign, partially cystic thyroid nodules with solid components.

MATERIALS AND METHOD

From April 2017 to April 2019, 46 patients with 47 large benign partially cystic thyroid nodules underwent sequential treatment. There were 14 men and 32 women with a mean age of 49.9±11.5 (SD) years (range: 18-75 years). The volume of initial nodules was 12.7±12.3 (SD) mL (range: 2.16-75.62mL). Volume reduction after percutaneous polidocanol sclerotherapy and further RFA was evaluated respectively. Patients had clinical and ultrasound evaluations at a follow-up time of 12.1±5.3 (SD) months (range: 1.5-23.9 months). Technical success and complications were accessed retrospectively.

RESULTS

After unsatisfying results with polidocanol sclerotherapy alone the 46 patients with 47 large benign partially cystic thyroid nodules had further RFA. Mean volume reduction of 47 nodules was 90.5±11.3 (SD) % (range: 43.9-99.3%) one month after RFA, 94.9±6.2 (SD) % (range: 66.9-99.5%) three months after RFA, and 95.8±5.5 (SD) % (range: 71.0-99.8%) six months after RFA. No recurrence or nodule enlargement after RFA was observed at the last follow-up. The complication rate of RFA was 12.5% (8/46 patients), with minor complications only.

CONCLUSIONS

The sequential treatment regimen, including percutaneous polidocanol sclerotherapy and RFA, is an appropriate and safe treatment strategy for large benign partially cystic thyroid nodules with solid components.