Background Inability to accurately identify parathyroid glands during cervical endocrine surgery hinders patients from achieving post-operative normocalcemia. An intrinsic near-infrared fluorescence method was developed for real-time parathyroid identification with high accuracy. This study assesses the clinical utility of this approach. Methods Autofluorescence measurements were obtained from 137 patients (264 parathyroid glands) undergoing parathyroidectomy and/or thyroidectomy. Measurements were correlated to disease state, calcium levels, parathyroid hormone (PTH), vitamin D levels, age, sex, ethnicity and body-mass index (BMI). Statistical analysis identified which factors significantly affect parathyroid detection. Results High parathyroid fluorescence was consistently detected and showed wide variability across patients. Near-infrared fluorescence was used to correctly identify 256/264 (97%) of glands. The technique showed high accuracy over a wide variety of disease states, though patients with secondary hyperparathyroidism demonstrated confounding results. Analysis revealed BMI (P<0.01), disease state (P<0.01), vitamin D (P<0.05), and calcium levels (P<0.05) account significantly for variability in signal intensity. Age, gender, PTH, and ethnicity had no effect. Conclusions This intrinsic fluorescence-based intraoperative technique can accurately detect nearly all parathyroid glands in real-time. Its discrimination capacity is largely unlimited by patient variables, but several factors affect signal intensity. These results demonstrate potential clinical utility of optical guidance for parathyroid detection.

NIR fluorescence imaging represents a highly sensitive, real-time, label-free tool for parathyroid localization during surgery. The elegance and effectiveness of NIR autofluorescence imaging of the parathyroid gland makes it highly attractive for clinical application in endocrine surgery.

Background Inadvertent removal of parathyroid glands is a challenge in endocrine operations. There is a critical need for a diagnostic tool that provides sensitive, real-time parathyroid detection during procedures. We have developed an intraoperative technique using near-infrared (NIR) fluorescence for in vivo, real-time detection of the parathyroid regardless of its pathologic state. Methods NIR fluorescence was measured intraoperatively from 45 patients undergoing parathyroidectomy and thyroidectomy. Spectra were measured from the parathyroid and surrounding neck tissues during the operation with the use of a portable, probe-based fluorescence system at 785-nm excitation. Accuracy was evaluated by comparison with histology or visual recognition by the surgeon. Results NIR fluorescence detected the parathyroid in 100% of patients. Parathyroid fluorescence was stronger (1.2–18 times) than that of the thyroid with peak fluorescence at 822 nm. Surrounding tissues showed no auto-fluorescence. Disease state did not affect the ability to discriminate parathyroid glands but may account for signal variability. Conclusions NIR fluorescence spectroscopy can detect intraoperatively the parathyroid regardless of tissue pathology. The signal may be caused by calcium-sensing receptors present in the parathyroid. The signal strength and consistency indicates the simplicity and effectiveness of this method. Its implementation may limit operative time, decrease costs, and improve operative success rates.

ACC continues to be a deadly disease, and little to no progress has been made from a treatment standpoint in the past 20 years. Careful and complete surgical resection is of the utmost importance. Although feasible in many cases and tempting, laparoscopic resection should not be attempted in patients with tumors suspicious for or known to be adrenocortical carcinoma.

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