The objective of this clinical feasibility study is to evaluate initial clinical safety and device performance of the CellFX Percutaneous Electrode (PE) System for the treatment of symptomatic benign thyroid nodules.

Cohort 1: (CellFX PE Procedure and Surgery) The first five enrolled subjects will be patients with planned thyroidectomy. The site investigator will perform the CellFX procedure followed by an ultrasound evaluation. The site investigator will then perform a partial or total thyroidectomy. Tissue samples from the CellFX targeted treated areas will be sent to the pathology lab for gross and histological evaluation. The participant will exit the study on the same day of surgery.

Cohort 2: (CellFX PE Procedure with 12 months follow-up) When Cohort 1 is completed, up to 25 subjects will undergo a CellFX treatment using a percutaneous approach under ultrasound guidance. After CellFX treatment, all subjects will be followed weekly until 1 month, 3 months, 6 months and 12 months post-CellFX PE procedure.

Inclusion Criteria:

• Participant must be at least 18 or no older than 80 years of age
• Participant gives voluntary, written informed consent to participate in this clinical investigation and from whom consent has been obtained.
• Participant must comply with study procedures including all follow-up visits diagnosis of thyroid nodule confirmed by ultrasonography ≤Grade 3 (2017 ACR TI-RADS and fine needle aspiration biopsy FNA (Bethesda category II ) with no macro-calcifications in target nodule within 30 days of enrollment
• Participant has single nodule ≤ 6.0 cm in greatest dimension.
• Participant may have abnormal thyroid function, such as suppressed thyrotropin (TSH) levels, at the screening visit
• Participant has no abnormal cervical lymph nodes during screening visit examination
• Participant has thyroid nodule causing appearance, pressure or swallowing symptoms
• Participant has absence of abnormal vocal cord mobility by ultrasound evaluation

Exclusion Criteria:

• Participant has an implantable electronic medical device. (i.e., pacemaker, implantable cardioverter defibrillator)
• Participant has an active systemic infection on the day of the CellFX PE procedure with either fever, leukocytosis or requiring intravenous antibiotics or history of head and neck, pulmonary or systemic infection in the last 2 weeks prior to CellFX PE procedure
• Participant is known to be immune compromised
• Participant is a member of a vulnerable population including individuals employed by the Sponsor, clinic site, or entity associated with the conduct of the study
• Participant had previous neck irradiation
• Participant has history of familial thyroid cancer in more than two first-degree relatives
• Participants currently suffering from hematological diseases or bleeding tendency, or patients currently requiring continuous administration of antiplatelet and anticoagulant drugs
• Ultrasonographic evidence of calcifications, irregular margins or sonographic features that are suspicious for malignancy
• Nodule likely to be in contact with the recurrent laryngeal nerve on ultrasound evaluation
• History of cardiac arrhythmia, uncontrolled hypertension, liver or kidney disease, or recent history of myocardial infarctions or structural heart disease as determined by the Investigator
• History of a coagulation mechanism disorder or bleeding tendency
• Abnormal contralateral vocal cord function
• Allergy or contraindication to assigned analgesia/anesthesia
• Females of childbearing potential who are nursing, pregnant, or planning to become pregnant during the study period
• Have any condition or situation which, in the Investigator's opinion, puts the participant at significant risk, could confound the study results, or may interfere significantly with the participant's participation in the study
• Use of any other investigational drug, therapy, or device within 30 days prior to enrollment or concurrent participation in another research study