Search

Due to its wide accessibility, easiness of use, and inexpensive cost, ultrasound (US) examination of the thyroid gland and cervical lymph nodes is commonly employed for the diagnosis of diffuse and nodular thyroid disease and for the pre-operatory staging and follow-up of patients with thyroid malignancy.

In the last two decades Peptide Receptor Radionuclide Therapy (PRRT) has acquired great importance as an alternative or complementary tool in the treatment of neuroendocrine tumors (NETs) and other somatostatin receptor (SSTR) positive tumors. Many experiences of PRRT using different radiopharmaceuticals, mainly beta-emitters 90Yttrium (90Y) and 177Lutetium (177Lu) labeled peptides, are reported in the literature with encouraging results in terms of tumor regression, self-assessed quality of life, and overall survival. SSTRs are mainly expressed in Gastro-Entero-Pancreatic neuroendocrine tumors (GEP-NETs) but in many other neoplasms (NETs and non-NETs) it is possible to find a high SSTR expression. Some of these are pheochromocytoma/paraganglioma, bronchial NET, thymic NET, meningioma, thyroid cancer (differentiated and medullary) and Merkel cell carcinoma.

Alcohol ablation, also known as percutaneous ethanol injection (PEI) and ethanol ablation (EA), has many applications for the treatment of endocrine neck diseases. Cell dehydration and protein denaturation, resulting in coagulative necrosis and fibrotic changes, are the immediate toxic effect induced by instillation of ethanol into the target tissue. EA is the first-line treatment for symptomatic cystic and predominantly cystic thyroid nodules. The efficacy of EA depends on a number of factors, e.g., the initial volume the lesion, the amount of ethanol instilled, the percentage of the solid component of the cyst. EA of thyroid cystic lesions is a safe procedure and no relevant side effects are usually recorded; nevertheless, being aware of the potential for recurrent laryngeal nerve (RLN) injury is required throughout the procedure. EA is not recommended for the treatment of either autonomously functioning thyroid nodules or solid cold thyroid nodules because of high recurrence rate, side effects, and the availability of other more effective ultrasound-guided interventional techniques. Regarding parathyroid (PT) lesions, EA can be used for treatment of large nonfunctional PT cysts and, in selected cases, for the treatment of hyperfunctioning PT glands in patients with chronic renal failure. Finally, EA can be used to treat metastatic lymph nodes from differentiated thyroid cancer in poor surgical candidates or patients seeking to avoid multiple reoperations.

The last 20 years have observed the proposal of several minimally invasive techniques for non-surgical treatment of thyroid nodules. This chapter describes, on the basis of our experience and of a brief literature review, the efficacy, safety, cost-effectiveness and current clinical indications of the first of these procedures: percutaneous ethanol injection (PEIT).