An interventional study of Near-Infrared Parathyroid Tissue Sensor Imaging (PTS) and Rim-Preservation Technique in Hyperparathyroidism, Primary, Parathyroid Neoplasms and Parathyroid Adenoma, sponsored by Fujian Medical University. Not yet recruiting at 1 site in China. Open to participants aged 18 Years to 75 Years. Per ClinicalTrials.gov, last updated 2025-06-29.
Sponsored by Fujian Medical University · Not applicable, Interventional, and Treatment
Primary hyperparathyroidism is usually cured by removing the single over-active parathyroid adenoma. During surgery, however, surgeons often see a thin rim of normal parathyroid tissue that still "glows" under a near-infrared parathyroid tissue sensor (PTS). It is unclear whether keeping this tissue in place helps preserve hormone function or whether it leaves behind cells that could become over-active again.
The WHITE CAP study will compare two common surgical choices:
Preservation strategy - the surgeon removes only the adenoma and leaves the glowing rim of normal tissue untouched.
En-bloc strategy - the surgeon removes the adenoma together with the glowing rim; if too little parathyroid tissue remains, a small fragment is transplanted into the forearm muscle.
About 120 adult patients who have a single parathyroid adenoma will be randomly assigned (like tossing a coin) to one of the two strategies. All operations will use the same FDA-cleared PTS camera that shows the glands in real time without dye or radiation.
The main question is whether preserving the normal rim lowers the rate of temporary low blood-calcium (numbness, tingling) during the first two days after surgery. The study will also check long-term results-blood calcium and parathyroid hormone (PTH) levels, symptoms, and any return of the disease-over two years.
The PTS imaging itself is painless and adds only a few minutes to the operation. Risks are the same as for standard parathyroid surgery, and participants can withdraw at any time without affecting their usual care.
Background and Rationale Near-infrared autofluorescence (NIRAF) highlights parathyroid tissue at a wavelength of 820 nm. Several devices, including Fluobeam LX and PTeye®, have FDA 510(k) clearance for intra-operative identification of parathyroid glands. In \~70 % of single-gland disease, NIRAF shows a viable rim of normal tissue partially encasing the adenoma. Retrospective data conflict on whether rim preservation reduces transient hypocalcaemia or increases recurrence. No prospective randomized evidence exists.
Objectives Primary: Compare the incidence of transient hypocalcaemia (albumin-corrected Ca \< 2.00 mmol·L-¹ or need for calcium/vit-D supplementation) within 48 h post-operative between preservation and en-bloc strategies.
Secondary: (i) Permanent hypocalcaemia at 6 months; (ii) PTH ≥ 15 pg·mL-¹ at 24 h; (iii) operative time and blood loss; (iv) biochemical or clinical recurrence up to 24 months; (v) correlation of quantitative NIRAF intensity with gland viability.
Study Design Multicentre, parallel-group, 1:1 randomized controlled trial (RCT). Block randomisation (size 4) stratified by centre and baseline vitamin-D status. Total sample 120 participants (60 per arm, includes 10 % attrition). Single-blind: outcome assessors and laboratory staff remain unaware of allocation.
Interventions Preservation arm: After adenoma excision, surgeon confirms NIRAF-positive rim and leaves it in situ; only minimal defatting to ensure vascularity.
En-bloc arm: Adenoma plus NIRAF-positive rim excised en bloc. If fewer than two normal glands remain in the neck, a 30 mg fragment is minced and autotransplanted into the non-dominant brachioradialis.
Eligibility Inclusion: age 18-75 y; biochemically confirmed primary hyperparathyroidism; imaging (MIBI or 4D-CT) concordant with a solitary adenoma; written informed consent.
Exclusion: multiple endocrine neoplasia, >1 enlarged gland on imaging, eGFR \< 30, pregnancy, neck re-exploration, planned concomitant total thyroidectomy.
Outcome Assessments Serum Ca, phosphate, Mg, PTH measured pre-op; 6 h, 24 h, 48 h; Day 7; Months 1, 6, 12, 24. Laryngoscopy if voice change occurs. Recurrence defined as Ca above upper limit plus PTH > 65 pg·mL-¹ after Month 12. NIRAF intensity recorded (arbitrary units) using standard ROI software.
Statistical Plan Transient hypocalcaemia expected 30 % in en-bloc vs 10 % in preservation. With α = 0.05, 1-β = 0.80, needs 54 per arm; rounded to 60. Intent-to-treat analysis. Risk ratios with 95 % CI; secondary continuous outcomes by mixed-effects ANCOVA. Interim safety review at 50 % recruitment (O'Brien-Fleming boundary).
Regulatory and Ethics PTS devices are FDA-cleared; study classified as non-significant-risk device research exempt from IDE (21 CFR 812.2(b)). All centres have IRB approval. Data stored in REDCap, anonymised, GDPR-compliant. A three-member DSMB (endocrine surgeon, endocrinologist, biostatistician) will monitor AEs; trial pause if permanent hypocalcaemia exceeds 15 %.
Data Sharing De-identified participant data and analytic code will be available upon reasonable request 6 months after primary publication.
104 studies on the registry are indexed under Hyperparathyroidism, Primary; 23 are open to participants now.
This study's planned enrollment of 120 is above the median of 68 across 60 interventional studies indexed under Hyperparathyroidism, Primary.
Browse Hyperparathyroidism, Primary studies →Fujian Medical University is the lead sponsor of 148 studies on the registry; 52 are open to participants now.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants undergo adenoma removal guided by PTS imaging, with deliberate preservation of the NIR-autofluorescent rim of normal parathyroid tissue.
Device: Near-Infrared Parathyroid Tissue Sensor Imaging (PTS) · Procedure: Rim-Preservation Technique
Participants undergo PTS-guided en-bloc excision of the adenoma plus its NIR-positive rim; parathyroid autotransplantation performed when indicated.
Device: Near-Infrared Parathyroid Tissue Sensor Imaging (PTS) · Procedure: En-bloc Resection Technique
FDA-cleared imager (e.g., Fluobeam LX/PTeye) providing real-time autofluorescence to identify parathyroid tissue during surgery; no dye or radiation.
Surgical excision of adenoma while leaving the NIRAF-positive rim of normal parathyroid tissue in situ; minimal defatting to ensure perfusion.
Surgical excision of adenoma together with the surrounding NIRAF-positive rim; autotransplant fragment if \< 2 normal glands remain in neck.
Incidence of Transient Hypocalcaemia
Proportion of participants whose albumin-corrected serum calcium falls \< 2.00 mmol/L or who require oral/IV calcium ± active vitamin D to maintain normocalcaemia within 48 h post-operatively. Blood samples at 6 h, 24 h, and 48 h will be analysed by a blinded central laboratory.
Time frame: Baseline to 48 hours after surgery (Post-op Day 0-2)
Permanent Hypocalcaemia
Need for ongoing calcium ± calcitriol to maintain normocalcaemia at ≥ 6 months after surgery.
Time frame: 6 months (±14 days) post-op
Parathyroid Hormone (PTH) Recovery ≥ 15 pg/mL
Percentage of patients with serum PTH ≥ 15 pg/mL at 24 h, indicating preserved parathyroid function.
Time frame: 24 hours post-op
Operative Time
Skin incision to skin closure, recorded by anaesthesia time stamp.
Time frame: Intra-operative (minutes)
Estimated Blood Loss
Calculated from suction canister minus irrigation plus soaked swab weight.
Time frame: Intra-operative (mL)
Biochemical or Clinical Recurrence
Recurrence defined as serum calcium above lab upper limit of normal + PTH \> 65 pg/mL and/or imaging-confirmed adenoma regrowth.
Time frame: 12 to 24 months post-op
Correlation of NIRAF Intensity with PTH Recovery
Spearman correlation between quantitative NIRAF counts (ROI) and 24-h PTH value.
Time frame: Intra-op & 24 hours post-op
Plan to share: Undecided
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Hyperparathyroidism, Primary →