Study Raises Concern over Imaging after Thyroid Cancer

Over the past two decades, the incidence of thyroid cancer has risen; most of this increase can be explained
by diagnoses of small, low-risk cancers. During this same period, the use of imaging after initial treatment has also increased, most likely due to growing concern about the risk of recurrence. But the relationship among imaging, treatment for recurrence, and disease-specific survival remains unknown.

Using data from the Surveillance Epidemiology and End Results-Medicare database, a team of researchers
identified 28,220 patients diagnosed with thyroid cancer between 1998 and 2011, according to results of a study
recently published in BMJ . The investigators monitored the use of imaging (neck ultrasounds, radioiodine scans, and positron emission tomography [PET] scans), additional treatment for recurrence, and deaths due to thyroid cancer through 2013.

They found that the use of neck ultrasounds, radioiodine scans, and PET scans was associated with additional treatment for recurrence, such as surgery, radioactive iodine treatment, or radiation therapy. Only the use of radioiodine scans was associated with improved survival from thyroid cancer.

This is an observational study, so no firm conclusions can be drawn about cause and effect, and the authors pointed to several limitations; however, they said it is not clear if the benefits of greater imaging outweigh the financial costs, heightened patient anxiety, and risk of patient harm from the treatment for recurrence.