Goiter, Nodular, Hypocalcemia, Hypoparathyroidism, Thyroid Diseases, Thyroidectomy, Thyroid Nodule
Conditions
Keywords
Near-Infrared Autofluorescence, NIRAF, Parathyroid Identification, Parathyroid Preservation, Thyroidectomy, Completion Thyroidectomy, Total Thyroidectomy, Postoperative Hypocalcemia, Intact Parathyroid Hormone, iPTH, Rescue Autotransplantation, Wearable Imaging, Post-thyroidectomy hypocalcemia
Brief summary
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.
Detailed description
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.
Interventions
A modified Meta head-mounted stereoscopic goggle system configured for label-free near-infrared autofluorescence imaging. The system delivers near-infrared excitation at approximately 780 nm and detects parathyroid autofluorescence centered near 800 nm. No injected dye or external contrast agent is administered. The device is used briefly after thyroid exposure for in vivo mapping and after thyroid resection for ex vivo specimen interrogation.
Sponsors
Study design
Masking description
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.
Intervention model description
This study includes two linked components. Component A is a prospective observational run-in validation cohort of 30 participants undergoing thyroidectomy of any extent. Component B is a prospective randomized parallel-group study of 250 participants undergoing total or completion thyroidectomy. Component B 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.
Eligibility
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.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Postoperative Day 1 Biochemical Hypocalcemia | Postoperative Day 1 | Proportion of randomized Component B participants with transient biochemical hypocalcemia on postoperative day 1, defined as albumin-corrected total serum calcium below the lower limit of the institutional clinical laboratory reference range in use at study activation. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Early Intact Parathyroid Hormone | 2 to 4 hours postoperatively, with optional assessment on Postoperative Day 1 | Early intact parathyroid hormone concentration used as an acute physiologic correlate of in situ parathyroid gland function. |
| Mapping Yield | Intraoperative | Number of parathyroid-consistent NIRAF sites identified during the intraoperative mapping interval. |
| Additional NIRAF Sites Beyond White-Light Assessment | Intraoperative | Number of NIRAF sites identified that were not included in the surgeon's pre-mapping white-light declaration. |
| Mapping Efficiency | Intraoperative | Time to first parathyroid identification with NIRAF imaging and total duration of the intraoperative mapping interval. |
| Incidental Parathyroid Tissue in the Thyroidectomy Specimen | Postoperative pathology review (up to 30 days postoperatively) | Presence and number of histologically confirmed parathyroid glands or parathyroid tissue fragments identified in the thyroidectomy specimen, including size when feasible. The number of confirmed parathyroid glands or tissue foci may be summarized categorically as 0, 1, 2, 3, or 4 when applicable. |
| Rescue Autotransplantation Events | Intraoperative | Whether rescue autotransplantation was performed, including tissue source, implant site, and number of fragments implanted. |
| Longer-Term Albumin-Corrected Serum Calcium | Postoperative week 8 and postoperative month 6 | Albumin-corrected total serum calcium concentration measured at postoperative follow-up. |
| Longer-Term Intact Parathyroid Hormone | Postoperative week 8 and postoperative month 6 | Serum intact parathyroid hormone concentration measured at postoperative follow-up. |
| Calcium or Calcitriol Supplementation at Follow-Up | Postoperative week 8 and postoperative month 6 | Use of oral calcium and/or calcitriol supplementation at postoperative follow-up. |
Countries
North Macedonia
Contacts
Ss. Cyril and Methodius University of Skopje