The area of the Thyroid gland is usually avoided during Ultherapy. The device doesn't go deep enough to affect the Thyroid. You should be ok. However, I would make sure you have your evaluation and procedure performed by a surgeon and not a technician as we have the best knowledge of the anatomy in the area. Best wishes.
The absolute deepest the Ultherapy could go is 4.5 millimeters and depending on what it looked like on ultrasound, there may not be any need to go that deep. Ultherapy of the neck is designed to treat at the platysma muscle and deep dermal layers. Any thyroid cancer or otherwise should we well deeper than the platyma muscle and not able to be penetrated by Ultherapy. Because Ultherapy is not actually a laser, there are not laws in California requiring an MD/PA/NP/RN to operate the machine. Make sure wherever you go, the technician has intimate understanding of neck anatomy and is well trained
There is no reason why the ultherapy, which is just focused ultrasound energy would affect the thyroid or if you had a history of cancer would cause any issues. Best, Dr. Emer.