The latest American Thyroid Association (ATA) guidelines for papillary thyroid cancer (PTC) recommend that low-risk patients be treated by removing only half of the thyroid gland, a procedure known as hemithyroidectomy.
However, even if some patients are considered low-risk before surgery, a final analysis by the pathology lab after surgery may show that their disease has progressed. These patients are often advised to undergo a completion thyroidectomy—a second surgery to remove the remaining section of thyroid. But this second surgery is inconvenient and costly, and poses the risk of undergoing another round of general anesthesia.
Mark L. Urken, Co-Director, Institute for Head and Neck and Thyroid Cancer, Mount Sinai Beth Israel
Last year, researchers led by Mark L. Urken, MD, of Mount Sinai Beth Israel, conducted a pilot study that showed that thyroid tissue could be tested during surgery to determine whether the cancer appeared aggressive. That would allow the entire thyroid to be removed at once when needed.
In this procedure, called intraoperative frozen section analysis, the surgeon removes the half of the thyroid in which the suspicious tumor is located. This lobe is then sent to an experienced pathologist to freeze, slice, and review under a microscope. In less than 20 minutes, the pathologist can report any evidence of aggressive features back to the surgeon that would drive the decision to perform a total thyroidectomy. These features include a tumor extending outside of the thyroid, tissue structures known to be aggressive, invasion of lymphatic system or blood vessels, multiple foci of disease, and the presence of lymph nodes that test positive for cancer.
During the pilot study, the researchers observed 26 patients undergoing a hemithyroidectomy for low-risk PTC. Intraoperative frozen section analysis revealed aggressive features in six of the patients. This allowed surgeons to proceed in removing the second half of the thyroid gland during the same surgical procedure, thus eliminating the health risks of secondary surgery.
One patient whose frozen section analysis did not indicate the need for complete thyroid removal later received a final diagnosis of follicular carcinoma and returned for a completion thyroidectomy. The remaining 19 patients were correctly categorized as low-risk PTC on frozen section analysis. There were no false positives – in other words, no one received a complete thyroidectomy who did not need one.
Overall, this pilot study determined that intraoperative frozen section analysis is a good way to verify a patient’s condition during surgery and reduce the number of times patients will have to come back for a second procedure. Frozen section analysis is a routine part of surgical procedure at Mount Sinai Beth Israel and ensures quality care for our thyroid cancer patients.