Thyroid Nodules Treated With High-intensity Focused Ultrasound (HIFU)
The Thyros Visualization and Treatment Unit (VTU)® is positioned on its robotic arm to deliver high-intensity ultrasound energy.
Illustration courtesy of Theraclion.
A device that delivers high-intensity focused ultrasound (HIFU) is now being investigated for the treatment of non-cancerous growths, or nodules, on the thyroid gland.
High-intensity focused ultrasound (HIFU) is currently used for the treatment of uterine fibroids, prostate cancer, and tumours of the liver, kidney, breast, abdomen and pancreas.[1]
How It Works
During HIFU treatment, a powerful, converging beam of energy causes the temperature to rise rapidly above 80ºC in an area about the size of a grain of rice. The heat causes cells to die at this precise focal point, without damaging surrounding tissue.
Thyroid treatment with HIFU takes 20 to 30 minutes in an outpatient clinic.[2] A local anesthetic is administered prior to treatment. The number of treatment sessions required depends on the number and size of the nodules.
Who Might Benefit
Thyroid nodules affect approximately 5% of women and 1% of men.[3] About 5% of nodules are cancerous and require surgical removal.[4] Most nodules are benign and do not require treatment unless they grow so large that they interfere with swallowing or breathing.[4] For these patients, the minimally invasive HIFU treatment may be an alternative to surgical removal of the nodular tissue.
Early Evidence
In an unpublished feasibility study to determine dosage, HIFU was applied to single, well-defined thyroid nodules in 25 patients with multi-nodular goiter, or enlarged thyroid gland, who were scheduled to have their thyroid removed. The ultrasound energy was gradually increased until more than 70% of the nodular tissue was destroyed.[5] The extent of tissue destruction was confirmed, following thyroid removal. Skin blistering and discomfort occurred frequently at the beginning of the study; however, the device head was subsequently redesigned and the last four patients had no skin damage.
Next Steps
Two pilot studies are underway in France; one for the treatment of benign thyroid nodules, and the second for the treatment of hyperactive or “hot” nodules, which release excessive amounts of thyroid hormone.
Regulatory Status
Theraclion (Paris, France) is developing the Thyros VTU® device. It is not currently licensed by any regulatory body.
Cost
The cost of the Thyros VTU device and associated treatment are currently unknown.
References
[1] Leslie TA, et al. Ultrasound Q 2006;22(4):263-72.
[2] Theraclion, the therapeutic HiFu specialist, raises 3.5 million Euros from Truffle Venture [news release]. Paris: Theraclion SAS; 2007 Feb 21. Available: http://www.genopole.net/media/pdf/eng/presse/050502-comm-theraclion-en.pdf
[3] Cooper DS, et al. Thyroid 2006;16(2):109-42.
[4] Guidelines and Protocols Advisory Committee. Thyroid function tests in the diagnosis and monitoring of adults with thyroid disease. Victoria: British Columbia Ministry of Health; 2004. Available: http://www.health.gov.bc.ca/gpac/pdf/thyroid.pdf
[5] Ultrasound therapy proves promising in thyroid, first clinical study finds [news release]. American Thyroid Association; 2006. Available: http://www.thyroid.org/professionals/publications/news/06_10_12_esnault.html