The goal of this clinical trial is to evaluate the therapeutic efficacy and safety of non-thermal plasma (NTP) as an adjuvant treatment for surgical bed decontamination and accelerated tissue repair in patients undergoing total thyroidectomy. The study aims to address the following objectives:

• Does the intraoperative application of NTP to the surgical bed and closed incision promote accelerated tissue regeneration compared to conventional postoperative care?
• Does NTP treatment reduce postoperative inflammatory response, pain intensity, and the incidence of site-specific complications (such as surgical site infection or seroma)?
• What is the safety profile of helium-based NTP in the cervical anatomical region regarding neighboring neurovascular structures?

Participants will be randomized into two arms:

1. The experimental group: Receiving a standardized application of helium-based NTP (at a frequency of 13.56 MHz) to the surgical bed prior to closure and subsequently to the sutured incision.
2. The control group: Receiving standard-of-care surgical wound management.

Clinical follow-up will include quantitative assessment of healing rates, pain scales (VAS), and biochemical or clinical markers of inflammation at scheduled intervals (Days 1, 7, 15, and up to 12 weeks post-surgery).

This prospective study addresses the two most critical limitations of conventional thyroid surgery: collateral thermal damage to noble structures and the risk of microscopic residual disease in incidental carcinoma cases.

The investigation focuses on the application of non-thermal plasma (NTP), a state of matter that generates a controlled 'cocktail' of Reactive Oxygen and Nitrogen Species (RONS). Unlike conventional energy-based devices (laser or electrocautery), NTP operates at low temperatures, eliminating lateral thermal dispersion and carbonization, thus preserving the functional integrity of the recurrent laryngeal nerve and parathyroid glands.

The standardized NTP protocol is executed in two distinct phases:

1. Phase I (Hemostasis and Neuroprotection): Following thyroid gland resection, the surgical bed is exposed to a power density of 0.5 W/cm² for 8-10 minutes. This phase targets the carotid sheath and the tracheoesophageal groove to ensure immediate hemostasis and to modulate the inflammatory response through redox signaling, thereby preventing exuberant fibroplasia.
2. Phase II (Selective Oncological Ablation): In cases where incidental malignancy is suspected or confirmed, an additional re-exposure of 10-12 minutes is performed specifically on the resection micro-margins. This phase leverages the selective cytotoxicity of RONS, which induces mitochondrial dysfunction and apoptosis in neoplastic cells while sparing healthy surrounding tissue.

The study aims to correlate this two-phase intervention with three primary clinical pillars: a) Absolute surgical safety (0% complication rate in nerve paralysis and hypocalcemia). b) Oncological sterilization (undetectable Thyroglobulin levels <0.1 ng/dL at 6 months). c) High-fidelity tissue mimicry (evaluated via VSS and POSAS scales), hypothesizing that NTP-mediated redox modulation achieves superior cosmetic and functional outcomes compared to traditional photobiomodulation.

Inclusion Criteria:

• Patients aged 18 years or older.
• Diagnosis of thyroid pathology requiring total or subtotal thyroidectomy.
• Signed Informed Consent Form (ICF).
• Patients capable of complying with the 12-week follow-up schedule.

Exclusion Criteria:

• History of previous neck surgery or radiation therapy in the cervical area.
• Known history of keloid formation or hypertrophic scarring.
• Presence of active systemic or local infection at the time of surgery.
• Patients with implanted electronic devices (e.g., pacemakers or defibrillators) due to the use of RF-based plasma.
• Pregnancy or breastfeeding.
• Concurrent use of systemic corticosteroids or immunosuppressive drugs that may impair wound healing.