Malignancy found in 25% of adults eligible for thyroid radiofrequency ablation
More than two-thirds of adults who underwent surgery for benign thyroid disease at a California health center were eligible for thyroid radiofrequency ablation, according to study findings published in Surgery.
Additionally, researchers found nearly one-quarter of participants eligible for thyroid radiofrequency ablation had an occult malignancy, and 8.1% had cancer of at least 1 cm in size.
“This finding suggests that as the U.S. experience with radiofrequency ablation grows, an increasing number of patients may undergo radiofrequency ablation instead of surgery as treatment for benign thyroid nodules,” Insoo Suh, MD, associate professor and associate vice chair of surgical intervention at NYU Langone Health, and colleagues wrote. “However, the rate of occult malignancy raises questions about the optimal preprocedural and long-term management of nondominant thyroid nodules in patients undergoing radiofrequency ablation.”
Researchers conducted a retrospective review of patients who underwent thyroid surgery for benign thyroid disease at the University of California in San Francisco from 2015 to 2019. Data on demographics and thyroid-specific variables, including preoperative cytopathology, surgical variables, postoperative outcomes and pathology, were collected from electronic medical records. Participants were deemed eligible for radiofrequency ablation if they had a Bethesda II cytopathology and either a maximum nodule dimension of greater than 2 cm regardless of local compression symptoms, a maximum nodule dimension less than 2 cm with local compression symptoms or toxic adenoma. A second round of data collection was performed on a subgroup of adults considered eligible for radiofrequency ablation and diagnosed with thyroid malignancy.
Of 411 patients meeting the study criteria, 284 were eligible for thyroid radiofrequency ablation as an alternative treatment approach. Of those eligible, 93.7% had a nodule of larger than 2 cm, 5.6% had a nodule smaller than 2 cm and 0.7% had toxic adenoma.
More than two-thirds (68.3%) of those eligible for radiofrequency ablation underwent thyroid lobectomy. After surgery, 7% experienced voice change, 4.2% had an abnormal postoperative laryngoscopy and 0.7% were dissatisfied or concerned about their scar.
Of the group eligible for radiofrequency ablation, 24.6% had occult malignancy and 8.1% had cancer of at least 1 cm in size. Of those with malignancy, the median dominant nodule size by pathology was 3.2 cm. The most common histopathology type was papillary thyroid cancer, which was found in 61.7% of those with malignancy. Follicular thyroid cancer or follicular variant papillary thyroid cancer were each observed in 16.7% of people with malignancy.
“Although most occult malignancies were microcarcinomas, this finding raises new questions about the optimal evaluation of nondominant nodules before radiofrequency ablation and long-term thyroid surveillance for patients who undergo radiofrequency ablation,” the researchers wrote. “Institutions interested in thyroid radiofrequency ablation may consider examination of their local demographics and surgical outcomes to better appreciate the implications of thyroid radiofrequency ablation in their patient population.”