[Ultrasonography-guided therapeutic procedures in the neck region].
BACKGROUND
Minimally invasive therapeutic procedures in medicine have become very popular because of the reduced risk compared to classic surgical treatment, speed of recovery, little or no side effects, and frequently lower cost. One of these methods is ultrasonography-guided percutaneous injection of 95% ethanol (PEIT, percutaneous ethanol injection therapy), which is especially suitable for the neck region. Other methods like laser photocoagulation (ILP) or radiofrequency ablation (RFA) are more aggressive and expensive.


METHODS
The procedure of sterile 95% ethanol injecting is performed on an outpatient basis, without preparation. A specific amount of alcohol is injected into the lesion using a thin spinal needle, under ultrasonography guidance. The amount of alcohol depends on the size of the lesion. Complications are rare and the procedure can be repeated several times. PEIT is used in the treatment of parathyroid glands, especially secondary hyperparathyroidism, thyroid nodules (toxic adenoma, goiters and cysts), other cysts on the neck, and cervical metastases of thyroid cancer.


CONCLUSIONS
Direct ethanol injection into the tissue causes cellular dehydration and protein denaturation, followed by the development of necrosis, fibrosis, and thrombosis of the small blood vessels. In this way, reduction or disappearance of the nodes can be achieved, along with functional normalization (for parathyroid glands and toxic adenoma), with longer or shorter disease remission or complete recovery. Today, PEIT is mostly used in dialyzed patients with secondary hyperparathyroidism. The treatment gives best results in combination with vitamin D analogs, if 1-2 parathyroid glands are enlarged, and for residual parathyroid gland after parathyroidectomy. A success rate of 50%-70% has been reported, depending on the number of enlarged parathyroid glands. Therapeutic effect is manifested in the size reduction or complete fibrozation of the gland, reduction or disappearance of vascularization, and a decrease in the parathormone level. PEIT produced best results in cysts (thyroid cysts, parathyroid cysts or other cysts on the neck), and can replace surgery. In most cases, results are achieved after the first injection. Volume reduction is between 50% and 95%, depending on the size and content of the cyst (clear, colloidal, or hemorrhagic) and presence of solid tissue. Therapy for toxic and autonomous thyroid adenoma and toxic nodular goiter by ethanol injection is accepted as one of the methods for treating patients that refuse radiation therapy or surgery. The goals of the treatment are nodal size reduction, normalization of thyroid hormones and TSH, and an improved subjective condition of the patient. Complete cure has been achieved in more than 75% of patients. Post-therapeutic development of hypothyroidism is extremely rare. The treatment can also be used for non-toxic goiter, especially those with cystic changes. PEIT is also recommended for the treatment of thyroid cancer neck metastases as an alternative procedure in patients at a high risk of reoperation, those that refuse surgery, and those with radioiodine-negative metastasis. The results of PEIT show significant reduction in nodal size or complete disappearance of the node in more than 70% of patients, with a decrease in serum thyroglobulin, except for patients with distant metastases. The procedure can be repeated until the desired effect is achieved, and is well tolerated by patients.


CONCLUSIONS
Therapeutic procedures under ultrasonography guidance are becoming ever more important in medical protocols. In the head and neck region, PEIT is the most widely used method because of a number of advantages. The simplicity of the procedure, relatively few side effects, low cost, outpatient treatment and good results make this method preferable to other, invasive therapeutic procedures.
Klinicki zavod za nuklearnu medicinu i zastitu od zracenja, Klinicki bolnicki centar Zagreb, Zagreb, Hrvatska. hrvojka@brzi.net
Hrvojka Tomić
HT
Brzac
D000431:Ethanol / Q000008:administration & dosage*; D006258:Head and Neck Neoplasms / Q000556:secondary / Q000628:therapy; D006801:Humans; D006962:Hyperparathyroidism, Secondary / Q000000981:diagnostic imaging / Q000628:therapy*; D015552:Injections, Intralesional; D015911:Sclerotherapy; D013959:Thyroid Diseases / Q000000981:diagnostic imaging / Q000628:therapy*; D018084:Ultrasonography, Interventional
D000431:Ethanol
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