Hemithyroidectomy vs. Total Thyroidectomy
Eric Genden, MD, MHCA, Isidore Friesner Professor and Chair of otolaryngology-head and neck surgery at the Icahn School of Medicine at Mount Sinai in New York, tackled the sometimes difficult question of hemithyroidectomy or total thyroidectomy for well-differentiated stage T2 tumors.
Explore this issue:March 2019
Because of the limitations inherent in assessing the extent of disease, patients should be given full explanations of the nuances at work, Dr. Genden said. “It is important to explain to patients that there are limitations to imaging and pathology in determining the presence of extrathyroidal extension, a contraindication to hemithyroidectomy,” he said. “Understanding these limitations is absolutely critical to shared decision-making.”
Dr. Genden surveyed a variety of practitioners, including 19 endocrinologists, head and neck surgeons, and pathologists regarding their approach to clinical management of patients with T2 disease and he found the responses were “quite disparate.” Pathologists expressed the concern that accuracy rates for ultrasound and CT scans are not great for predicting extrathyroidal extension preoperatively. That’s because, they say, the popular concept that the thyroid gland is well-encapsulated is erroneous. Not uncommonly, pathologists will identify normal thyroid tissue that has escaped through the pseudocapsule and into the surrounding muscle, suggesting that imaging may be misleading. “Extracapsular extension exists in a fair number of benign etiologies,” Dr. Genden said.
Also, he said, ultrasound is limited in its ability to detect peritracheal nodal disease, and those he queried during his informal survey repeatedly emphasized that ultrasound is operator-dependent. He added that nodules in the contralateral lobe were a strong indication to pursue a total thyroidectomy.
Regarding active surveillance, he said “very few endocrinologists were comfortable sitting tight, even with the most benign-looking tumors.”
Also, Hashimoto’s disease, glandular irregularity, and multifocal disease were typically an impetus for total thyroidectomy, particularly for endocrinologists who say the more aggressive procedure makes surveillance easier. Surgeons tend to be split, Dr. Genden said, but added, “Everybody agreed across the board that it’s a multi-disciplinary disease. It requires endocrinology evaluation.”
Dr. Genden also emphasized that in the face of imperfect imaging and limitations regarding pathological confirmation of extrathyroidal extension, patients should be made aware of these limitations to support the shared-decision making process. Dr. Genden said that the “management of T2 thyroid disease remains an imperfect science; it is still an art.”
Loss of Signal
When signal is lost on one side after surgery for thyroid cancer, it is a serious situation, as borne out by statistics, said Gregory Randolph, MD, professor of otolaryngology-head and neck surgery and the Clair and John Bertucci Chair in thyroid surgical oncology at Harvard Medical School in Boston, who helped lead the International Neural Monitoring Study Group’s (INMSG) most recent thyroid guidelines, which looked at incidence of vocal cord paralysis, cost effectiveness of neural monitoring during thyroid surgery, and monitoring methods.
The expected rate of paralysis on the second side should be—all things being equal—about half a percent or one percentage point. But actually, in the world’s literature, the group found, it’s 17%. “It is a high stakes situation once you lose that ipsilateral signal,” Dr. Randolph said.