This is a single-site, two-component prospective study evaluating whether near-infrared autofluorescence (NIRAF) imaging can improve intraoperative identification of parathyroid glands during thyroidectomy and reduce postoperative hypocalcemia.

The investigational platform is a modified wearable stereoscopic goggle system configured for label-free NIRAF imaging. Parathyroid tissue is excited with near-infrared light at approximately 780 nm and emits autofluorescence centered near 800 nm. No injected dye or external contrast agent is used. The goggles are used only during a brief mapping interval after thyroid exposure and for ex vivo interrogation of the resected thyroid specimen.

Component A is a prospective observational run-in validation cohort of 30 adults undergoing thyroidectomy of any extent. NIRAF-positive foci on the intact thyroidectomy specimen are suture-marked and correlated with targeted pathology.

Component B is a randomized clinical study of 250 adults undergoing total or completion thyroidectomy. Participants are randomized 1:1 to standard surgery or standard surgery plus brief in vivo NIRAF mapping, ex vivo specimen interrogation, and rescue autotransplantation when indicated. The primary outcome for Component B is transient biochemical hypocalcemia on postoperative day 1, defined using albumin-corrected serum calcium.

Near-infrared autofluorescence (NIRAF) imaging is being evaluated as a structured adjunct to standard thyroidectomy for localization and preservation of parathyroid tissue. Parathyroid tissue emits intrinsic near-infrared autofluorescence without administration of dye or other contrast agent. The study imaging platform is a modified head-mounted stereoscopic goggle system that provides near-infrared excitation at approximately 780 nm and detects autofluorescence centered near 800 nm. Imaging is non-contact and is performed only during a brief prespecified in vivo mapping interval and ex vivo back-table specimen interrogation.

The study includes a run-in validation component followed by a randomized interventional component. In the run-in component, ex vivo imaging of thyroidectomy specimens is used to standardize imaging conditions, documentation, suture marking, specimen mapping, and pathology correlation for NIRAF-positive foci. In the randomized component, participants undergoing total or completion thyroidectomy are randomized to standard surgery or standard surgery plus adjunct NIRAF mapping. In the intervention arm, the surgeon records parathyroid glands identified under white light before mapping, then uses NIRAF information as an adjunct to standard anatomy and surgical judgment. After thyroid removal, ex vivo specimen imaging may be used to identify NIRAF-bright foci that could represent inadvertently excised parathyroid tissue. Rescue autotransplantation may be performed only when clinically appropriate and oncologically safe.

NIRAF findings are intended to supplement, not replace, standard operative assessment, surgical anatomy, pathology review, or oncologic decision-making.

Inclusion Criteria:

• Age 18 years or older.
• For Component A: planned thyroidectomy of any extent with an intact specimen available for ex vivo evaluation.
• For Component B: planned total or completion thyroidectomy.
• Ability to provide written informed consent before surgery.
• Willingness to comply with routine postoperative laboratory testing and follow-up when feasible.

Exclusion Criteria:

• Known pre-existing hypoparathyroidism or prior parathyroid surgery.
• Severe chronic kidney disease or end-stage renal disease expected to substantially confound calcium and parathyroid hormone interpretation, as defined by the site investigator.
• Pregnancy.
• For Component B only: gross nodal disease or a surgical plan requiring extensive nodal packet dissection in the current study phase.
• Any condition that, in the judgment of the investigator, would make participation unsafe or compromise protocol adherence.

No individual participant data will be shared with outside researchers. Deidentified aggregate study results may be reported in scientific presentations and publications.

The study is open label. Blinding of the operating surgeon is not feasible because the intervention involves intraoperative use of the NIRAF imaging device. Laboratory values and pathology findings are objective outcomes and will be analyzed using prespecified definitions.