Efficacy and Safety of RFA vs MWA for Treatment of Large Benign Thyroid Nodules, RCT

August 31, 2026 updated by: Man Him Matrix Fung, The University of Hong Kong

Comparing the Efficacy and Safety of Radiofrequency Ablation Versus Microwave Ablation for the Treatment of Large Benign Thyroid Nodules, a Randomized Controlled Trial

We will conduct a multi-institutional randomized control trial of RFA and MWA for the primary treatment of large, benign nodules. Adult patients >/=18 years of age who have a solitary thyroid nodule ≥20ml in volume who presents to 1) Columbia University, NY or 2) Queen Mary Hospital, Hong Kong for consultation will be eligible for enrollment in the study. They will need either a) two benign fine needle biopsies, with the most recent biopsy performed within 1 year of enrollment in study or b) one benign fine needle biopsy and low suspicion characteristics on ultrasound. Both functional and non-functional nodules are eligible. After thorough evaluation of each individual case and if the eligibility criteria are met, participants will be offered ultrasound guided thermal ablation as a viable option for management of their nodule. If they consent to undergo thermal ablation and consent to participation in the study, patients will be randomly assigned to either treatment arm a) RFA or treatment arm b) MWA according to a pre-generated block randomization list created using www.sealedenvelope.com.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

There is an estimated 10% lifetime probability for developing a thyroid nodule. Although up to 15% of these nodules will prove to be malignant, most thyroid nodules that are identified are benign nodules. However, even benign nodules can continue to grow to a size that start to cause compressive symptoms for patients, including neck pressure and discomfort, dysphagia, dyspnea, and dysphonia. Some nodules will become autonomously functioning causing hyperthyroidism. Traditionally the gold standard treatment for these benign, but problematic nodules, has been thyroidectomy. Although generally a low risk operation, thyroidectomy is associated with some risk for recurrent laryngeal nerve injury, bleeding, infection, and need for thyroid hormone supplementation.

Introduced in the early 2000s, ultrasound-guided percutaneous ablation of thyroid lesions has emerged as a potential alternative to surgery in patients with benign thyroid nodules. Of the myriad ablation methods, the most commonly used technique is radiofrequency ablation (RFA). An expanding body of evidence shows that radiofrequency ablation and other percutaneous interventions are effective treatments for benign solid thyroid nodules, toxic adenomas, and thyroid cysts resulting in overall volume reduction ranges of 40-70% with durable resolution of compressive and hyperthyroid symptoms. However, RFA is not without its limitations. Radiofrequency waves can be limited by the heat sink effect and tissue char leading to longer procedure times and potentially less optimal outcomes in larger, hypervascular, and/or more cystic nodules.

Microwave ablation (MWA) is another ablative technique that uses electromagnetic energy waves to cause tissue hyperthermia and coagulative necrosis. It generally causes higher ablation temperatures than RFA and is less subject to the heat sink effect, and therefore can facilitate more efficient ablation procedures. Current evidence comparing RFA versus MWA for thyroid ablation were limited and were either retrospective or non-randomized, with focus mainly on small thyroid nodules of ≤10ml in volume. There is a lack of high quality evidence on the safety and efficacy of RFA versus MWA for the treatment of large thyroid nodules (≥20ml). Given the higher ablation temperatures, freedom from heat sink effect and no influence from impedance changes during ablation, MWA may achieve different treatment efficacy in large nodules.

The aim of this randomized controlled trial is to compare the safety and efficacy of RFA and MWA in the treatment of large, benign thyroid nodules. We hypothesize that MWA is not inferior to RFA in terms of complication rate and overall volume reduction of large, benign nodules, but will also be associated with overall decrease in procedure time and procedural discomfort. Patients with large benign thyroid nodules ≥20ml will be considered for recruitment. Suitable subjects will be randomized to receive either RFA or MWA according to a pre-generated block randomization list at a 1:1 ratio. The primary outcome of is the volume reduction rate at 6 months and one year after ablation. The secondary outcomes include safety, complication rates and quality of life after both procedures.

Study Type

Interventional

Enrollment (Estimated)

25

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

  • Name: Man Him, Matrix Dr. Fung, MBBS
  • Phone Number: +852 2255 4232
  • Email: mmhfung@hku.hk

Study Locations

  • Hong Kong
      • Hong Kong, Hong Kong
        • Recruiting
        • Queen Mary Hospital
        • Contact:
          • Man Him, Matrix Dr. Fung, MBBS
          • Phone Number: +852-22554232
          • Email: mmhfung@hku.hk

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • who have a solitary thyroid nodule ≥20ml in volume
  • two benign fine needle biopsies, with the most recent biopsy performed within 1 year of enrollment in study or one benign fine needle biopsy and low suspicion characteristics on ultrasound
  • Both functional and non-functional nodules are eligible

Exclusion Criteria:

  • have multiple nodules and planned simultaneous ablation
  • indeterminate nodules classified benign
  • nodules with substernal extension or posterior extension that cannot be viewed sufficiently with ultrasound
  • current pregnancy or cardiac arrhythmias

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Microwave ablation
Apply microwave ablation to those large benign thyroid nodules for shrinkage purpose
Device: Microwave ablation
Ultrasound-guided thermal ablation will be performed using ECO Medical internally cooled MWA antennas (16 or 17 gauge) powered by the ECO Medical generator in accordance with the 'moving shot' technique described by Baek et al. The MWA procedure uses image guidance to place an electrode through the skin into the target area. In MWA, high frequency electromagnetic waves are passed through an electrode, creating a small region of heat to treat the lesion.
Other Names:
  • MWA
Experimental: Radiofrequency ablation
Apply radiofrequency ablation to those large benign thyroid nodules for shrinkage purpose
Device: Radiofrequency ablation alone
Ultrasound-guided thermal ablation will be performed using STARmed internally cooled RFA electrodes (18 gauge) powered by the VIVA RF generator in accordance with the 'moving shot' technique described by Baek et al. The RFA procedure uses image guidance to place an electrode through the skin into the target area. In RFA, high frequency electrical currents are passed through an electrode, creating a small region of heat to treat the lesion.
Other Names:
  • RFA

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Volume reduction rate (VRR) of thyroid nodule at 6 months and 12 months (%)
Time Frame: 6 months and 12 months
To measure the volume reduction rate (VRR) of thyroid nodule at 6-month and 12-month volume of nodule= length(cm) x width(cm) x depth(cm) x (π / 6 ) VRR = [(volume at baseline - volume at 6-month or 12-month)/volume of baseline] x 100%
6 months and 12 months
Complications from procedure including vocal cord palsy, bleeding, infection, nodule rupture, skin burn
Time Frame: 12 months
To assess any complications from procedure during follow-up period after ablation
12 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Changes in compressive symptom scores (0-100)
Time Frame: 12 months
To measure the changes in compressive symptoms scores. Compressive symptoms score is from 0 to 100. The higher score means more compressive symptom.
12 months
Changes in cosmetic symptom scores (1-4)
Time Frame: 12 months

To assess the change of cosmetic symptom by experienced doctors until 12 months.

Cosmetic symptoms is from 1 to 4 as below

  1. = no palpable goitre
  2. = Palpable goiter but invisible
  3. = Goitre only visible to experienced clinician
  4. = Easily visible goitre
12 months
Peri-operative pain scores (0-10)
Time Frame: 12 months
To measure the change in pain score before and after ablation. The pain score is from 0 to 10, the higher score means more painful.
12 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

The University of Hong Kong

Collaborators

Columbia University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

December 5, 2023

Primary Completion (Estimated)

November 1, 2026

Study Completion (Estimated)

June 30, 2027

Study Registration Dates

First Submitted

August 31, 2026

First Submitted That Met QC Criteria

August 31, 2026

First Posted (Actual)

September 4, 2026

Study Record Updates

Last Update Posted (Actual)

September 4, 2026

Last Update Submitted That Met QC Criteria

August 31, 2026

Last Verified

August 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • UW 23-574

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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