Thyroid nodules are common, appearing on ultrasound in up to 50% of women and 30% of men. Most are benign, but nodules that grow or cause symptoms may need attention. Thyroid RFA offers a minimally invasive, non-surgical way to reduce nodule size, ease symptoms and preserve normal thyroid function.
Thyroid nodules are common in the adult population, with a prevalence at ultrasound (US) examination of up to 50% in adult females and 30% in males. Most lesions are cytologically benign and neither cause local symptoms nor warrant treatment.
However, a non-negligible proportion of patients will experience pressure symptoms, complain of cosmetic concerns, or develop subclinical or overt hyperthyroidism due to an autonomously functioning thyroid nodule (AFTN).
While surgery has been the traditional treatment approach, increasingly, patients may be keen on a non-surgical option to avoid the risks of:
- General anaesthesia
- Surgical complications of thyroid surgery
- Cosmetic effects of thyroid surgery
Depending on the diagnosis of your thyroid problem, several non-surgical options are available. Your thyroid doctor will need to order a panel of blood tests as well as an ultrasound of your thyroid.
A thyroid nuclear scintigraphy scan may also be ordered, although this is becoming infrequent. Some of these tests may be repeated over a period of time. The purpose of which is to note the trend of disease progression, which may not be evident on a single static test.
I. Medication
If there is an underlying problem of over- or under-production of thyroid hormone, medication is certainly indicated.
In the past, excessive doses of thyroid hormone (levothyroxine) were prescribed to suppress the growth of a nodule in the setting of a euthyroid condition (normal hormone levels).
However, this is no longer practised as the side-effects of long-term hyperthyroidism, such as cardiac arrhythmias and osteoporosis, exceed the intended benefit.
II. Radio-iodine ablative therapy
The administration of radioactive nuclide I131(RAI) induces thyroidal cell death through direct and indirect damage to cell DNA.
In the context of benign thyroid disease, I131 is indicated in hyperthyroidism due to Graves’ disease or toxic goitre from single toxic adenomas or multinodular goitre. It may also be used in subclinical hyperthyroidism and euthyroid goitre.
In thyroid cancers, I131 ablation is recommended as adjuvant therapy for patients who have undergone total thyroidectomy for high-risk cancers. It may also be offered to patients with distant metastases or sites not amenable to surgical resection, which are iodine-avid.
RAI is administered in oral form. Even though the term “radioactive” may sound frightening, RAI is a safe, generally well-tolerated, and reliable treatment that targets thyroid cells specifically, so there is little exposure to the rest of your body.
However, women who are pregnant, intending to be pregnant, or nursing should not receive RAI therapy:
Pregnancy should be delayed at least six to 12 months after RAI treatment. Breastfeeding should be stopped at least six weeks before RAI and should not be resumed.
Other concerns regarding RAI treatment include the need for repeated treatment, the unpredictability of results as well as the negative long-term effects of treatment.
III. Thermal ablation, Thyroid Radiofrequency Ablation (RFA)
In recent times, thermal ablation (TA) is increasingly offered as an alternative to surgery for the treatment of benign thyroid nodules.
It is based on an irreversible nodule damage induced by an increase in tissue temperature and selectively destroys a predictable area of the nodule while sparing the surrounding normal tissue.
There are various thermal ablation techniques, of which radiofrequency ablation (RFA) is one of the most popular treatment modalities. Others include laser, microwave ablation and high-intensity focused ultrasound (HIFU).
Ethanol ablation is an older treatment modality generally reserved for thyroid cysts. RFA tесhnоlоgу is not new; It hаs been used therapeutically fоr a wide rаngе оf соndіtіоns іnсludіng nerve раіn, сеrtаіn tуреs оf саnсеr, utеrіnе fіbrоіds, as well as sоmе vascular conditions.
The advantages of TA in thyroid nodules are its cost and risk-effectiveness in accomplishing the patient’s demand for shrinking benign nodules and improving local symptoms less invasively than with surgery.
This means the avoidance of post-operative hypothyroidism. Another advantage is the fact that TA can be performed in the outpatient or clinic setting, thus avoiding unnecessary hospital admissions.
In response to the proliferation of TA as a treatment modality in recent times, the European Thyroid Association (ETA) has published a set of guidelines.
Some of which are listed below:
- Adult patients with benign thyroid nodules that cause pressure symptoms and/or cosmetic concerns and who decline surgery, image-guided thermal ablation (TA) should be considered as an alternative to surgical treatment or observation alone
- TA is not recommended for asymptomatic lesions or lesions with high-risk ultrasound features
- A benign cytological diagnosis is needed before TA (based on two benign FNAC results), except for spongiform nodules and pure cystic lesions
- TA is generally not indicated for multinodular goitres unless in the setting of a well-defined dominant nodule or when patients are not candidates for thyroid surgery or radioactive iodine treatment
- Long-term monitoring every 1-2 years is recommended, even in the absence of symptoms, to ensure no re-growth occurs
IV. Close monitoring with surveillance ultrasound
Thе gоаl in the management of thуrоіd nоdulеs is to design an орtіmаl, personalised risk-based аррrоасh that minimises repeated tеstіng and unnесеssаrу invasive intervention.
Hence, an active survеіllаnсе regimen using ultrasound is ideal as it has no radiation exposure, is inexpensive and readily available and repeated without the need for special preparation.
Ultrasound-guided fine needle biopsy of thyroid nodules may be repeated to exclude malignancy.