Preservation of normal thyroid function is paramount even if a patient has large and symptomatic thyroid nodules. Large thyroid nodules cause symptoms from compression of adjacent tissue. A non- surgical alternative to thyroidectomy and radio- iodine ablation is now available for effective treatment of large benign nodules. With RFA, tissue volume reduction and symptom relief are accomplished through pinhole incisions with long term protection of normal thyroid function. Symptomatic patients and patients with visible enlargement are candidates for this alternative therapy to surgery.
Patients who have large nodules (over 2 cm in dimension) which have been identified either by CT scan or ultrasound and who have have symptoms from the nodules. One or many individual ultrasound guided FNA biopsies of the nodule in question are necessary. These biopsies must demonstrate benign pathology.
Continuous enlargement occurs in approximately 11% of patient’s nodules. These larger nodules will become more symptomatic as they encroach on adjacent structures. Tissue is either compressed or shifted from normal anatomic location. Additionally, nodules producing excessive thyroid hormone cause many other health problems.
Current guidelines are well defined regarding nodules proven to be benign with several biopsies. Additionally, the nodule should be over 2 cm in size and not deep to the clavicle. All nodules identified by ultrasound should have a benign appearance, and all nodules treated should be individually biopsied. Nodules should not be larger than 50ml
Anyone who is hypothyroid or has had prior thyroid surgery is a poor candidate. Additionally, those patients who have indeterminate biopsies (AUS or FLUS) without genetic testing will require further testing. Anyone with thyroid cancer is not currently a candidate for therapy
Unless the nodule is an autonomous functioning nodule (rarely malignant), two individual biopsies are required to conclude that a lesion is not cancer. With RFA therapy the tissue is not removed and sent to the pathologist for analysis. After RFA therapy, surveillance ultrasound might identify irregularities within the nodule which could be interpreted as suspicious. This interpretation may prompt further biopsies. Because cytology tissue may look more atypical after RFA treatment assurance of benign tissue is very important prior to therapy.
Pregnancy, active coronary disease, prior neck irradiation, prior thyroid or lymph node malignancy, and anti-coagulation therapy. Thyroid nodules located deep to the clavicle are very difficult to treat with this approach.
Some patients have hyperthyroidism related to a nodule with autonomous function (AFTN). These nodules make some patients hyperthyroid, or mildly hyperthyroid. This clinical entity can lead to both symptoms of anxiety and fatigue. Longstanding hyperthyroid patients develop heart conditions as well as osteoporosis. The determination of AFTN is optimally made with an I131 Iodine Uptake Scan which demonstrates increased iodine uptake in the nodule compared to the remainder of the gland. Until now the only therapy available for these patients was either surgery or radioactive iodine ablation. Radioactive iodine ablation causes hypothyroidism in one year in about 85% of patients. Ultimately these people will require daily thyroid medication. Surgery requires the removal of the entire thyroid lobe containing the autonomous nodule. The alternative therapy which destroys these nodules with RFA successfully avoids an operation and hypothyroidism. Restoration of normal thyroid function is accomplished in most patients. Generally, no daily thyroid medications are required after RFA.
Hyperthyroidism caused by Grave’s disease is a contraindication for this therapy.
On the day of the treatment we do not advise returning to work. The day after your therapy you will be examined to inspect the treated area with ultrasound. You may return to work following that brief visit.
In patients who have one sided disease less than 50 ml of thyroid nodule volume, one treatment is very successful. For safety reasons, patients who have two sided disease will require two separate treatment sessions. Patients who have disease greater than 50 ml may elect to undergo surgery or can be treated in two sessions about 12-18 month apart.
A wide-field cervical nerve plexus block is performed with a local anesthetic. This field block is performed using local anesthesia and US guidance. This effectively numbs the anterior neck and capsule of the thyroid where the nerves are present. Because the internal aspect of the thyroid gland has no sensation, the treatment can be performed with little pain.
Optimal therapy includes communication with the patients during the procedure. General anesthesia is less desirable because the patient cannot speak. Under local anesthesia, we are still able to converse with the patient to assess the quality of the voice. Although rarely necessary, interventions to protect the recurrent laryngeal nerve can be initiated should the patient’s voice becomes weak or hoarse.
Usually oral Tylenol and/or Ibuprofen are adequate after ablation. Taking a mild anti-anxiety, anti-spasm medication tablet such as Valium prior to the procedure can improve the level of comfort during the procedure as well.
The effectiveness if therapy is partially measured by nodule volume reduction as well as preservation of normal thyroid function. The international data for nodule reduction has been overwhelmingly favorable for nodule reduction during the immediate months after therapy. We aim for a 60% reduction in volume at 3 months and a 90% volume reduction in one year. The success of the ablation is determined by the amount of energy applied in each nodule as well as the precision of the delivery. Expertise in ultrasound guided therapies is therefore a requirement to perform these challenging procedures.
Determination of therapy after a biopsy result may be complex. The evaluation of tissue on slides may not always determine if the tissue is benign. Surgical removal of the nodule for further analysis is appropriate therapy. For patients interested in a nonsurgical approach, the nodule can be further studied with genetic classification testing. This is an added expense and may determine if a nodule is benign. In this situation the appropriateness of RFA therapy can be considered. Some nodules may still require surgery in order to determine their innate behavior. If a scar-less approach is preferred, than Dr. Harding can discuss an endoscopic technique to remove the thyroid gland which leaves no visible scars. Currently he is the only surgeon in Arizona who is trained and experienced with this endoscopic trans-oral approach.
Radiofrequency ablation (RFA) is a targeted therapy which uses electric energy and heat to destroy the abnormal tissue. RAI is Radioactive Iodine therapy which involves ingesting the radioactive tablet containing the radioactive iodine. This is taken up by all thyroid tissue including the enlarged and hyperfunctioning nodule. The radioactive energy destroys the genetic elements in the thyroid cells and eventually destroys the tissue. Hypothyroidism is a common problem after RAI, but not RFA.
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