Effect of perithyroidal lignocaine infusion (PLI) to pain experienced during high-intensity focused ultrasound (HIFU) ablation of benign thyroid nodules

Efficacy of HIFU for the treatment of benign thyroid nodules: a systematic review and meta-analysis

OBJECTIVE

Thyroid nodules are common and sometimes associated with cosmetic issues. Surgical treatment has several disadvantages, including visible scarring. High-intensity focused ultrasound (HIFU) is a recent noninvasive treatment for thyroid nodules. The present study aims to evaluate the effectiveness and safety of HIFU for the treatment of benign thyroid nodules.

METHODS

We searched PubMed, Embase, and Cochrane Library for studies evaluating the outcomes of HIFU for patients with benign thyroid nodules. We conducted a meta-analysis by using a random effects model and evaluated the volume reduction ratio, treatment success rate, and incidence of treatment-related complications.

RESULTS

Thirty-two studies were included in the systematic review. Only 14 studies were used in the meta-analysis because the other 18 involved data collected during overlapping periods. The average volume reduction ratios at 3, 6, and 12 months after treatment were 39.02% (95% CI: 27.57 to 50.47%, I2: 97.9%), 48.55% (95% CI: 35.53 to 61.57%, I2: 98.2%), and 55.02% (95% CI: 41.55 to 68.48%, I2: 99%), respectively. Regarding complications, the incidences of vocal cord paresis and Horner's syndrome after HIFU were 2.1% (95% CI: 0.2 to 4.1%, I2: 14.6%) and 0.7% (95% CI: 0 to 1.9%, I2: 0%), respectively.

CONCLUSIONS

HIFU is an effective and safe treatment option for patients with benign thyroid nodules. However, the effects of HIFU on nodules of large sizes and with different properties require further investigation. Additional studies, particularly randomized controlled trials involving long-term follow-up, are warranted.

CLINICAL RELEVANCE STATEMENT

Surgical treatment for thyroid nodules often results in permanent visible scars and is associated with a risk of bleeding, nerve injury, and hypothyroidism. High-intensity focused ultrasound may be an alternative for patients with benign thyroid nodules.

KEY POINTS

• The success rate of HIFU treatment for thyroid nodules is 75.8% at 6 months. Average volume reduction ratios are 48.55% and 55.02% at 6 and 12 months. • The incidence of complications such as vocal fold paresis, Horner's syndrome, recurrent laryngeal nerve palsy, hypothyroidism, and skin redness is low. • HIFU is both effective and safe as a treatment for benign thyroid nodules.

A comprehensive review of interventional ablation techniques for the management of thyroid nodules and metastatic lymph nodes

Thyroidectomy remains the gold standard treatment for benign, symptomatic, or enlarging thyroid nodules, malignant nodules, and metastatic lymph node disease. However, in the past 2 decades, image-guided interventional techniques have emerged as promising alternative treatments for these conditions. Percutaneous ethanol ablation is now an accepted first-line treatment for recurring cystic thyroid nodules. Thermal ablation techniques such as high-intensity focused ultrasound, laser ablation, radiofrequency ablation, and microwave ablation have shown efficacy in producing a nodular volume reduction of greater than 50% that is maintained for several years with resolution of local compressive symptoms. There is also increasing evidence that these techniques can effectively treat papillary thyroid microcarcinomas and recurrent metastatic lymph node disease. Because these interventional ablation techniques are performed safely in an outpatient setting, are well tolerated, and the risk for needing thyroid hormone supplementation is negligible, they are becoming a popular alternative treatment to surgical resection. In this comprehensive review, we discuss each of these percutaneous interventions: the devices and techniques, the advantages and disadvantages of each energy, and summarize the outcomes published in the literature.

High-intensity focused ultrasound (HIFU) therapy for benign thyroid nodules: a 3-year retrospective multicenter follow-up study

BACKGROUND

Outcomes of high-intensity focused ultrasound (HIFU), as a non-surgical treatment option for benign symptomatic thyroid nodules, has mainly been based on single-center studies and short-term follow-up. Therefore, we assessed the safety, and long-term efficacy of HIFU in benign thyroid nodules among four centers with expertise in thyroid mini-invasive procedures.

PATIENTS AND METHODS

Retrospective three year follow-up study in four European centers, treating solid benign thyroid nodules causing pressure symptoms and/or cosmetic concerns. Nodule volume reduction was assessed at 1, 3, 6, 12, 24, and 36 months post-treatment. Technical efficacy, defined as a volume reduction rate (VVR) >50% was evaluated at 6, 12, 24 and 36 months. Predictive factors of efficacy were assessed using logistic models. Complications and side effects were classified according to the Interventional Radiology Guidelines and changes in local symptoms were scored on a visual-analog scale.

RESULTS

Sixty-five patients (mean age 51.1 ± 14.0 years; 86.2% women) with a single thyroid nodule and a mean baseline nodule volume of 9.8 ± 10.3 mL were treated with a mean energy of 7.1 ± 3.1 kJ (range: 2.0 to 15.5 kJ). Median nodule volume reduction was 31.5% (IQR: -38.6% to -23.1%) at 12 months and 31.9% (IQR: -36.4% to -16.1%) at 36 months. Technical efficacy was obtained in 17.2% of cases at 6 months, 17.8% at 12 months, 3.4% at 24 months, and 7.4% at 36 months. The number of treated pixels and the mean energy delivered were positively correlated to VRR at 1, 6 and 12 months. The risk of treatment failure decreased by 4.3% for each additional unit of energy delivered. The procedure duration was inversely correlated with treatment failure (OR 1.043, 95% CI: 1.011-1.083; p = 0.014). Improvement of cervical pressure symptoms or cosmetic complaints were observed in less than 15% of the cases at 12, 24 and 36 months. Horner's syndrome occurred in one case (1.5%) and minor complications, not requiring treatment, in three (4.6%) patients. No change in thyroid function was registered.

CONCLUSIONS

HIFU carried a low risk of complications. A single treatment resulted in a 30-35% thyroid nodule volume decrease within one year, reduction that remained stable for 2 years. Outcomes varied significantly between centers with different HIFU expertise. Focus on improved HIFU technology, adequate training, and appropriate selection of patients is needed to achieve efficacy comparable to other thermal ablation procedures.

Horner's Syndrome During High-Intensity Focused Ultrasound Ablation for a Benign Thyroid Nodule

Objective

Horner's syndrome (HS) is a rare complication of high-intensity focused ultrasound (HIFU) and radiofrequency ablation for thyroid nodules. We present such a case and discuss how to avoid this complication in the future.

Methods

This case occurred during HIFU treatment of a benign thyroid nodule (BTN). Ultrasound and fine-needle aspiration cytology (FNAC) were performed before the procedure. Volume reduction was evaluated at 6 weeks, 3, 6, and 12 months. Technical success was ≥50% reduction at 6 months.

Results

A 30-year-old woman presented with a solitary symptomatic thyroid nodule. Her thyroid stimulating hormone was 1.16 (ref 0.4-3.6) μUI/mL), ultrasound found a 13 mL right-thyroid EU-TIRADS 4 nodule. Two FNACs were read as Bethesda II. The subsequent HIFU procedure was conducted with local 2% lidocaine anesthesia. The procedure was painful (visual analogic scale 10/10) and ipsilateral partial ptosis occurred during the procedure. Volume reduction at 12 months was 34.6% of the initial volume with persisting functional and cosmetic complaints, discomfort, and partial ptosis. As the volume reduction was ≤50%, the procedure was a technical failure. A new FNAC was read as Bethesda IV. A right lobectomy was performed without postoperative outcomes and without requiring hormonal replacement therapy. Pathological evaluation found no malignant cells.

Conclusion

HS is a rare complication of HIFU for management of BTNs. It may be symptomatic and have sequalae that persist for months. Severe neck pain may by associated, but further investigation is needed.

Single-session high-intensity focused ultrasound (HIFU) ablation for benign thyroid nodules: a systematic review

BACKGROUND

Thyroid nodules are common; the majority of them are benign and asymptomatic. Thyroidectomy might be an option; however, the frequency of post-operative complications mandates the development of alternative approaches, such as high-intensity focused ultrasound ablation (HIFU). HIFU induces thermal destruction without penetrating the skin. The present systematic review aims to synthesize all available data, evaluating studies with single-session HIFU therapy and investigating its efficacy.

MATERIALS AND METHODS

This systematic review was conducted in accordance with the PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and MetaAnalyses). Eligible articles were identified by a search of Medline bibliographic database (PubMed) and Cochrane Library. Out of 39 results, 11 articles were considered to meet the inclusion criteria.

RESULTS

All eligible studies included patients with solid or predominantly solid benign thyroid nodules. All patients were treated with the same HIFU device. The success rate of the method was defined in the majority, with the volume reduction rate (VRR) over 50% from baseline. The mean or median VRR ranged from 48.7 to 70.41%, depending on the last follow-up date. No major complications were observed.

CONCLUSION

Single-session HIFU is safe and effective for the treatment of benign thyroid nodules.

The current state and future perspectives of high intensity focused ultrasound (HIFU) ablation for benign thyroid nodules

High intensity focused ultrasound (HIFU) is a new thermoablation technique used to treat benign thyroid nodules. In this method, the ultrasound beam passes through the patient's skin and focuses very precisely on the target lesion at a distance far from the source of ultrasound generation, making HIFU the only truly non-invasive method of thermoablation developed to date. HIFU is therefore an attractive alternative to surgery and other thermoablative techniques. This review describes the principles of HIFU treatment, the selection of patients suitable for HIFU, the course and effects of treatment, and future perspectives.