Integrated Device for in Vivo Fine Needle Aspiration Biopsy and Elastic Scattering Spectroscopy in Preoperative Thyroid Nodules

Abstract

Thyroid nodules are a frequent clinical finding and the most common endocrine malignancy is thyroid cancer. The standard of care in the management of a patient with a thyroid nodule is to perform a preoperative fine needle aspiration (FNA) biopsy of the suspect nodule under ultrasound imaging guidance. In a significant percentage of the cases, cytological assessment of the biopsy material yields indeterminate results, the consequence of which is diagnostic thyroidectomy. Unfortunately, 75–80% of diagnostic thyroidectomies following indeterminate cytology result in benign designation by postsurgery histopathology, indicating potentially unnecessary surgeries. Clearly, the potential exists for the improvement in patient care and the reduction of overall procedure costs if an improved preoperative diagnostic technique was developed. Elastic scattering spectroscopy (ESS) is an optical biopsy technique that is mediated by optical fiber probes and has been shown to be effective in differentiating benign from malignant thyroid tissue in ex vivo surgical tissue samples. The goal of the current research was to integrate the ESS fiber optic probes into a device that can also collect cells for cytological assessment and, thus, enable concurrent spectroscopic interrogation and biopsy of a suspect nodule with a single needle penetration. The primary challenges to designing the device included miniaturizing the standard ESS fiber optic probe to fit within an FNA needle and maintaining the needle’s aspiration functionality. We demonstrate the value of the fabricated prototype devices by assessing their preliminary performance in an ongoing clinical study with >120 patients. The devices have proven to be clinically friendly, collecting both aspirated cells and optical data from the same location in thyroid nodules and with minimal disruption of clinical procedure. In the future, such integrated devices could be used to complement FNAbased cytological results and have the potential to both reduce the number of diagnostic thyroidectomies on benign nodules and improve the surgical approach for patients with thyroid malignancies, thereby, decreasing healthcare costs and improving patient outcomes.