Clinical trial NCT03012438: NIRF for Parathyroid Visualization: a Pilot Study
Official title: The Use of Near-Infrared Fluorescence Imaging in Parathyroid Visualization During Thyroid Surgery: a Pilot Study
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Thyroid Disease
Keywords: Near infrared fluorescence
ICG
Parathyroid gland
Lead sponsor: Maastricht University Medical Center
Sponsor class: OTHER
First posted: 2017-01-06
Enrollment: 30
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: NA
Intervention model: SINGLE_GROUP
Primary purpose: DIAGNOSTIC

Brief summary: During surgery in which the thyroid is removed (thyroidectomy), the identification of parathyroid glands, that should be saved, can be challenging. Therefore, there is need for accurate intraoperative guidance. Earlier animal studies show that the parathyroid glands can be identified by the use of the Near Infrared Fluorescent dye Indocyanine green (ICG).

Our hypothesis is therefore, that the use of ICG-based fluorescence imaging during thyroid surgery will provide real-time intraoperative visualization of the parathyroid glands.

This prospective observational feasibility study aims to evaluate the feasibility of the use of ICG in identifying the parathyroid glands during thyroid surgery. 30 patients (age \>18 years) who are already regularly scheduled for thyroid surgery; i.e. patients undergoing total thyroidectomy are suitable for inclusion. In all patients, undergoing total thyroidectomy infrared fluorescence imaging, using a per-operative intravenous injection of 7.5 mg ICG, will be tested on feasibility and imaging characteristics.

Detailed description: In this study, the feasibility of the use of NIR fluorescence imaging for the identification of the parathyroid glands during thyroid surgery will be explored.

Per-operatively: The surgery will start as usual. When the surgeon would normally search for the parathyroid glands, 7.5 mg of ICG will be administered intravenously through the infusion in the patients arm. An intravenous administration is chosen because of the minimal invasive nature and results of the described earlier case series in which ICG was also administered via peripheral infusion. Directly after that, the fluorescence system can be switched to fluorescence mode. The surgeon will determine whether the parathyroid glands are visible now. If needed, due to washout, a second dose of 7.5 mg of ICG can be administered. After identification of the parathyroid glands, surgery will continue as in the standard situation, until there is a desire to visualize the parathyroid glands again, then another dose of ICG can be given. Time until first identification of the parathyroid glands and total surgical time will be measured. After complete removal of the thyroid, another 7.5 mg of ICG will be administered intravenously to visualize the vascularization of the parathyroid gland. The intensity will be subjectively scored: 1 parathyroid black after injection of ICG, 2 partially vascularized, or 3 parathyroid is green; well vascularized. The fluorescence system will be used to record the whole procedure. Directly after the procedure the researcher will ask the surgeon whether he or she thinks the technique is feasible.

Postoperatively: As in standard care, after thyroid surgery, the serum calcium levels will be determined. Low calcium levels can indicate misidentification of parathyroid glands. These calcium levels are determined only in patients after total thyroidectomy on day 1, 2 and after two weeks. Also TSH will be determined after two weeks as in standard care. The thyroid specimen will be send to pathology. In the specimen, the pathologist will search for parathyroid glands, as is standard care. Furthermore, video recordings will be analyzed, quantifying the fluorescence signal compared to the background: measuring the Target to Background Ratio. Also, in these video recordings the time until visualization of the parathyroid glands will be reassessed by an independent expert.

Eligibility criteria: Inclusion Criteria:

* Male or female patients, aged 18 years and above
* Scheduled for elective total or hemi thyroidectomy
* Normal liver and renal function
* No known hypersensitivity for iodine or ICG
* Able to understand the nature of the study procedures
* Willing to participate and give written informed consent

Exclusion Criteria:

* Age \< 18 years
* Liver or renal insufficiency
* Known ICG, iodine, penicillin or sulfa hypersensitivity
* Pregnancy or breastfeeding
* Not able to understand the nature of the study procedure
* i.v. heparin injection in the last 24h (LMWH not contraindicated)
* Not willing to participate

Primary outcomes:
measure: Time to identification of parathyroid glans
timeFrame: during surgery
Secondary outcomes:
measure: Total surgical time
timeFrame: From incision until closure
measure: Histology: are parathyroid glands in the specimen? (as in standard care)
timeFrame: assessment within 1 week after surgery
measure: Subjective opinion surgeon about the usefulness of the technique
timeFrame: Immediately after surgery
measure: Intra-operative complications due to the use of the technique
timeFrame: during surgery
Other outcomes:
measure: Quantitative measurement of fluorescence signal related to parathyroid function
timeFrame: up to 2 weeks
Locations:
city: Maastricht
country: Netherlands
facility: Maastricht University Medical Center
state: Limburg
Study officials:
affiliation: Maastricht University Medical Center
name: Nicole Bouvy, M.D. Ph.D.
role: PRINCIPAL_INVESTIGATOR
References: