Early results of an in vivo trial of ESS in thyroid cancer

Introduction: Thyroid cancer is the most common endocrine malignancy. The current gold standard for diagnosis, fine-needle aspiration (FNA) biopsy, yields 10-25% of indeterminate cytology results, leading to patients undergoing thyroidectomy for diagnosis. We assessed the technical potential of a miniaturized in vivo ESS (elastic light scattering spectroscopy) probe, built into an FNA needle assembly, to differentiate benign from malignant thyroid nodules. Methods: Under IRB approval, 15 patients in the endocrine clinic undergoing FNAB of a thyroid nodule had collection of ESS data using our novel miniaturized FNA probe. Using final surgical pathology as our gold standard, data post processing and visual inspection was completed. Results: 225 spectra were grouped and analyzed (120 benign, 30 malignant and 75 from indeterminate cytology). ESS probes demonstrated excellent reproducibility in use. Initial analysis of these preliminary data is promising, indicating distinction of spectral ESS features between malignant and benign conditions. Conclusion(s): An in vivo trial of an invasive miniaturized integrated ESS biopsy probe is acceptable to patients, and collection of ESS data is feasible and reliable. With development of a disease-specific algorithm, ESS could potentially be used as an in-situ real time intra-operative diagnostic tool or as a minimally invasive adjunct to conventional FNA cytology.