Evaluating Impact of NIRAF Detection for Identifying Parathyroid Glands During Parathyroidectomy

Inability of the surgeon to identify or localize the diseased PG can occur in 5 - 10% of cases resulting in failed parathyroidectomies (PTx). As a result, persistent hyperparathyroidism can occur in these patients resulting in unnecessary repeat surgeries that may be associated with increased morbidity and costs. Ultrasound imaging, 99mTechnetium-sestamibi scintigraphy, and computed tomography (CT) have so far demonstrated variable efficacy in preoperative localization of diseased PGs and may not always correlate well with the surgical field of view as observed intraoperatively. Consequently, most surgeons rely on visual identification of PGs during surgery, whereby the accuracy of PG identification is eventually determined by her/his surgical skill and experience. When in doubt, a surgeon routinely confirms the identity of PG tissue intraoperatively by sending the specimen for frozen section analysis that typically requires a wait time of 20-30 minutes per sample and has additional costs.

By easily being able to distinguish parathyroid from other tissues intraoperatively, postsurgical complications and associated costs may be reduced. The unique discovery of near infrared autofluorescence (NIRAF) in parathyroid tissues demonstrated that optical modalities that detect NIRAF can be utilized for non-invasive and label-free identification of parathyroid tissues with an accuracy as high as 97%. Since then, several research groups have explored the feasibility of localizing parathyroid glands using NIRAF detection with reasonable success, resulting in FDA clearance for marketing this optical technique. In this study, we plan to evaluate whether an FDA-cleared device called 'PTeye' (AiBiomed, Santa Barbara, CA) is beneficial or not, for the surgeon and patient during PTx operations. The results of such a study will help us to understand and assess the true impact of optical modalities such as PTeye on (i) improving the quality and efficiency of PTx surgeries and (ii) minimizing risk of postsurgical complications and related expenses.

The aim of this prospective single blinded randomized study is to compare 2 groups of patients: PTx patients operated using NIRAF detection technology with PTeye as adjunct tool (NIRAF+) vs. patients operated without the adjunct technology (NIRAF-). The main objective of this study is to assess the benefit of intraoperative use of NIRAF detection technology via PTeye during PTx procedures with regard to PG identification, duration of surgery, number of frozen section analysis performed, number of intraoperative PTH assays sent and incidence of postsurgical complications, if any and history of ER visits or hospitalization or repeat surgeries due to persistent high blood calcium after PTx procedure, compared to standard of care.

Inclusion criteria

• All primary hyperparathyroidism patients eligible for parathyroidectomy (PTx). Both bilateral and focused mode of PTx will be considered for this study, based on the surgeon's preference.
• Re-operative primary hyperparathyroidism patients who have undergone a failed prior PTx.

Exclusion criteria

• Patients with concurrent parathyroid and thyroid disease that require total thyroidectomy.
• Patients with secondary or tertiary hyperparathyroidism.