Fiber Bragg Gratings for Temperature Monitoring during Thyroid Microwave Ablation: a Preliminary Analysis

Traditional methods to treat thyroid nodules like thyroidectomy and radioiodine therapy can involve a multitude of risks, such as damages to parathyroid glands and aftercare hypothyroidism. Minimally invasive surgery (MIS) can represent an alternative solution, avoiding general anesthesia or radioactive substances. In the framework of MIS, thermal ablation therapies (TATs) are gaining momentum to treat both benign and malign tumors by inducing a significant temperature variation inside the treated tissue. Among TATs, microwave ablation (MWA) is a newly emerging technique which has proved to be an effective and safe method in treating tumors in different organs like liver and kidney, more recently including thyroid nodules. However, an experimental analysis of the temperature reached within the thyroid tissue during the treatment has not been performed yet. Temperature monitoring during TATs can be beneficial to ensure the complete tumor eradication, especially in case of new challenging organs like thyroid. In this regard, this work aims to assess the spatial and temporal distribution of the temperature increment during MWA by performing ex vivo tests on swine thyroid. Temperature variations have been recorded by means of different arrays of fiber optic Bragg grating sensors (FBGs), each of those embedding ten sensing points in parallel to the MW applicator inside the tissue. These trials could provide the first stage in the further investigation of thyroid MWA, towards a better understanding of the most suitable treatment settings for this kind of tumor to improve the treatment outcomes.