Multicenter trial confirms near-infrared autofluorescence increases detection of parathyroid glands

A team led by Vanderbilt University and Vanderbilt University Medical Center biomedical engineers and surgeons has published results of a large clinical trial showing that use of a near-infrared autofluorescence (NIRAF) probe device improves intraoperative identification of parathyroid glands (PGs).

The biomedical engineers and surgeons published the results of the first multicenter, randomized clinical trial using this technology during endocrine neck procedures in JAMA Surgery.

While endocrine neck surgery is generally safe with a low rate of complications, inadvertent removal and damage to PGs can cause hypoparathyroidism, a condition that can lead to low levels of calcium and elevated levels of phosphorus in the blood.

Long-term hypoparathyroidism complications include impaired kidney function, cardiac arrhythmias and increased risk of death. Because of this, it is crucial to accurately identify these glands during parathyroidectomy and thyroidectomy.

In 2018, the Food and Drug Administration granted de novo classification and marketing authorization for a device to assist with detection of parathyroid glands in adults called the PTeye, which was used in this trial.

The device was developed by the Vanderbilt Biophotonics Center, led by Anita Mahadevan-Jansen, Ph.D., the Orrin H. Ingram Professor of Engineering. Its clinical implementation was pioneered by a group of VUMC surgeons led by Carmen Solórzano, MD, chair of the Department of Surgery, John L. Sawyers Professor of Surgical Sciences and director of Vanderbilt Endocrine Surgery.

“NIRAF technology leverages the fact that parathyroid tissue emits a stronger near-infrared autofluorescence signal than other tissues in the neck, so it glows in the surgical field when using our device,” said Mahadevan-Jansen.

“Our team has been working diligently for several years to take this from concept in our lab to clinical practice. It is gratifying to now have this large, multicenter clinical trial provide further evidence of its impact in successfully and efficiently identifying PGs during surgery. It is our ultimate goal to improve the accuracy of endocrine neck surgeries, which will lead to improved patient outcomes.”

There are typically four parathyroid glands in the human body. The multisite randomized clinical trial showed a significant increase in the mean number of PGs identified during thyroidectomies using the probe-based NIRAF—3.3 versus 2.8 without the device.

In bilateral parathyroidectomies, there was also an improvement in the mean number of PGs identified using the device (3.5) versus without (3.2). Using the device did not add value during focused procedures where a single overactive PG was targeted for removal.

For both the NIRAF and control groups having thyroidectomies, there was no significant reduction in the rates of transient or long-term hypoparathyroidism.

“PGs can have unpredictable locations and can be found anywhere in the neck from just below the jaw to the chest, near the heart,” said Solórzano.

“Normal PGs are about the size of a lentil and look like other tissues in the neck, so they can be difficult to locate and identify, even for skilled surgeons. Our previous clinical trial at VUMC showed an accuracy rate of 97% when using the device to detect PGs.

“Relying on eyesight alone during thyroid or parathyroid procedures might not bring the best outcomes, so we are excited to now have further evidence of the accuracy of this device and to have it available to surgeons throughout the world.”

The clinical trial was conducted at four medical centers between March 2020 and July 2024. It involved 752 patients undergoing surgery for primary hyperthyroidism or thyroid disease, with a six-month follow-up. In addition to VUMC, the clinical trial was also performed by investigators at the University of Michigan, University of California-San Francisco and the Medical College of Wisconsin-Milwaukee.

A team led by Vanderbilt University and Vanderbilt University Medical Center biomedical engineers and surgeons has published results of a large clinical trial showing that use of a near-infrared autofluorescence (NIRAF) probe device improves intraoperative identification of parathyroid glands (PGs).

The biomedical engineers and surgeons published the results of the first multicenter, randomized clinical trial using this technology during endocrine neck procedures in JAMA Surgery.

While endocrine neck surgery is generally safe with a low rate of complications, inadvertent removal and damage to PGs can cause hypoparathyroidism, a condition that can lead to low levels of calcium and elevated levels of phosphorus in the blood.

Long-term hypoparathyroidism complications include impaired kidney function, cardiac arrhythmias and increased risk of death. Because of this, it is crucial to accurately identify these glands during parathyroidectomy and thyroidectomy.

In 2018, the Food and Drug Administration granted de novo classification and marketing authorization for a device to assist with detection of parathyroid glands in adults called the PTeye, which was used in this trial.

The device was developed by the Vanderbilt Biophotonics Center, led by Anita Mahadevan-Jansen, Ph.D., the Orrin H. Ingram Professor of Engineering. Its clinical implementation was pioneered by a group of VUMC surgeons led by Carmen Solórzano, MD, chair of the Department of Surgery, John L. Sawyers Professor of Surgical Sciences and director of Vanderbilt Endocrine Surgery.

“NIRAF technology leverages the fact that parathyroid tissue emits a stronger near-infrared autofluorescence signal than other tissues in the neck, so it glows in the surgical field when using our device,” said Mahadevan-Jansen.

“Our team has been working diligently for several years to take this from concept in our lab to clinical practice. It is gratifying to now have this large, multicenter clinical trial provide further evidence of its impact in successfully and efficiently identifying PGs during surgery. It is our ultimate goal to improve the accuracy of endocrine neck surgeries, which will lead to improved patient outcomes.”

There are typically four parathyroid glands in the human body. The multisite randomized clinical trial showed a significant increase in the mean number of PGs identified during thyroidectomies using the probe-based NIRAF—3.3 versus 2.8 without the device.

In bilateral parathyroidectomies, there was also an improvement in the mean number of PGs identified using the device (3.5) versus without (3.2). Using the device did not add value during focused procedures where a single overactive PG was targeted for removal.

For both the NIRAF and control groups having thyroidectomies, there was no significant reduction in the rates of transient or long-term hypoparathyroidism.

“PGs can have unpredictable locations and can be found anywhere in the neck from just below the jaw to the chest, near the heart,” said Solórzano.

“Normal PGs are about the size of a lentil and look like other tissues in the neck, so they can be difficult to locate and identify, even for skilled surgeons. Our previous clinical trial at VUMC showed an accuracy rate of 97% when using the device to detect PGs.

“Relying on eyesight alone during thyroid or parathyroid procedures might not bring the best outcomes, so we are excited to now have further evidence of the accuracy of this device and to have it available to surgeons throughout the world.”

The clinical trial was conducted at four medical centers between March 2020 and July 2024. It involved 752 patients undergoing surgery for primary hyperthyroidism or thyroid disease, with a six-month follow-up. In addition to VUMC, the clinical trial was also performed by investigators at the University of Michigan, University of California-San Francisco and the Medical College of Wisconsin-Milwaukee.