One-Third Of Thyroid Ultrasounds May Be Unnecessary: Study

According to the findings of a new study, nearly one out of every three thyroid ultrasounds may be unnecessary, potentially leading to an over diagnosis of low risk thyroid cancers.

Researchers with the University of Michigan Rogel Cancer Center published a report this month in the medical journal JAMA Surgery, which indicates many doctors order thyroid ultrasounds at patients’ request, ignoring current medical guidelines that establish when the exams are considered necessary.

The study involved a survey of 610 surgeons, endocrinologists, and primary care physicians who were involved in thyroid cancer care. Doctors were given different patient scenarios and asked when they would schedule a thyroid or neck ultrasound, and about one-third indicated that they would order an ultrasound for reasons that are not supported by clinical care guidelines.

A third of those who did so said they ordered the ultrasound because the patient wanted it, while 28% said they ordered it because of abnormal thyroid function tests.

Routine use of ultrasounds to detect cancerous thyroid nodules have led to an increase in diagnosed thyroid cancer cases. However, many of these cases are low risk and unlikely to cause serious harm, according to the researchers.

Roughly half of people over the age of 40 have thyroid nodules. Most of the nodules found are harmless, but 15% of those are malignant and can spread to the lymph nodes in the neck. Other tumors grow slowly causing little risk to the patient, but have the possibility of spreading to the lymph nodes if left untreated. However, if more ultrasounds are conducted many of the benign nodules and low risk tumors will undergo unnecessary treatment, which can include biopsy, surgery, and radiation. This can result in patients facing increased healthcare costs, other health side effects, and more stress and worry.

While most thyroid ultrasounds are warranted, researchers said guidelines should be clearer to reduce over diagnosis of thyroid cancer. For example, it should be warranted for a large nodule that can be felt or seen or was seen on another imaging test.

Seventy percent of doctors said recent clinical guidelines had the most influence on their decisions for patients with thyroid nodules.

Several organizations, like the American Thyroid Association, offer care guidelines based on data and outcomes from published studies, but there is no universal specific guideline for when to order a thyroid ultrasound.

“This study is the first to look at why physicians are using thyroid ultrasound for patients. While often it’s for clinically relevant reasons, a substantial number of physicians are not ordering them for reasons that are clinically supported,” wrote senior study author Dr. Megan R. Haymart, Nancy Wigginton Endocrinology Research Professor of Thyroid Cancer and professor of internal medicine at Michigan Medicine.

The key is to identify those thyroid cancers that will require treatment, but avoid over diagnosis of nodules that are small or slow growing and may never need treatment.

Researchers hope the findings of the study and any guidelines developed in the future can help educate doctors and patients and perhaps change doctor behavior regarding ultrasound recommendations, which may help reduce the incidence of low risk thyroid cancer being diagnosed.