Rrelapsed Graves' Disease Clinical Trial
Official title:
A Prospective Evaluation of High Intensity Focused Ultrasound (HIFU) in the Treatment of Relapsed Graves' Disease
To evaluate the short-term efficiency and safety of HIFU treatment in the relapsed Graves' disease.
Grave's disease is the most common cause of hyperthyroidism and affects approximately 2% of
women and 0.2% of men in the population. The use of antithyroid drugs (ATD) has been the
first-line of treatment for Graves' disease in many centers for decades, and its use has
been increasing worldwide. One reason for this is that it may induce remission, whereas
radioiodine (RAI) and surgery often lead to hypothyroidism and other complications in
addition to hospitalization and radiation exposure. However, ATD use is also associated with
increasing risk of some adverse minor effects such as skin rash, gastric intolerance, and
arthralgia in 5% of patients. Furthermore, major adverse events, such as agranulocytosis and
hepatotoxicity may be life-threatening but are rare (<0.5% of cases). These usually occur
during the first three to six months of treatment, and tend to be associated with high ATD
doses. Therefore, the recommended duration of ATD treatment is generally not longer than
12-24 months. However, despite adequate medical treatment, up to 50-70% of patients with
Graves' disease would relapse or recur and therefore, a more definitive approach using RAI
treatment or thyroid surgery is eventually needed for the resolution of hyperthyroidism.
Although RAI is considered safe and easy to manage, particularly in patients without Grave's
ophthalmopathy (GO), subclinical and overt hypothyroidism may occur months or even years
after the administration of RAI. Hence, long-term follow-up of thyroid function and GO as
well as management of thyroxine replacement is necessary. Similarly, although surgery is the
main therapeutic strategy, it carries a 2%-10% risk of complications such as hypocalcemia,
transient or permanent recurrent laryngeal nerve palsy, bleeding, or postoperative
infection. In view of these, various nonsurgical, minimally invasive treatment alternatives
have been developed at specialized treatment centers.
High-intensity focused ultrasound (HIFU) is a noninvasive procedure that involves
application of a focused high-energy ultrasound beam for thermal tissue ablation inside the
targeted zone, with minimal effect on the surrounding tissue. This method has been applied
for treatment of a variety of medical conditions such as uterine fibroids and prostate,
breast, pancreatic, and liver tumors. A favorable outcome also has been observed in patients
with primary or secondary hyperparathyroidism. HIFU has also been proposed for thyroid
nodule ablation . In a human feasibility study, 25 patients were treated 2 weeks before a
scheduled thyroidectomy. Pathologic analysis demonstrated targeted tissue destruction of
2%-80% without any damage to neighboring structures. To the investigators knowledge, studies
of follow-up after HIFU ablation of Graves' disease have not been published, except for one
report where two patients received a combination of microwave ablation and RAI. Thus, the
purpose of this prospective study is to assess the short-term efficacy and safety of
US-guided HIFU ablation for the treatment of relapsed Graves' disease.
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Endpoint Classification: Safety/Efficacy Study, Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Treatment