Analysis has found that a subset of patients with thyroid cancer treated with thyroidectomy can be safely monitored through other means.
Repeat neck ultrasounds ‘should be avoided’ after treatment for most thyroid cancers
June 24, 2019
Among patients with low- or intermediate-risk differentiated thyroid cancer who underwent thyroidectomy, surveillance can safely be based on periodic serum thyroglobulin assays without the routine use of neck ultrasound if the initial imaging assessment reveals no evidence of disease, according to a retrospective analysis published in The Journal of Clinical Endocrinology & Metabolism.
“The majority of patients with papillary thyroid carcinomas we see in clinical practice have a low risk of recurrence after the initial treatment,” Cosimo Durante, MD, PhD, associate professor of internal medicine at the Sapienza University of Rome, told Endocrine Today. “These individuals, in the absence of clinical evidence of disease at the 1-year follow-up visit, can be safely addressed with a more relaxed monitoring program, including a periodic clinical assessment and serum thyroglobulin assays on thyroid hormone replacement therapy. Repeated neck ultrasound should be avoided.”
In a retrospective study, Durante and colleagues analyzed data from 226 patients with differentiated thyroid carcinomas diagnosed between 2007 and 2014, with primary treatment consisting of total thyroidectomy. Patients had sonographically normal neck lymph nodes and unstimulated serum thyroglobulin levels that were undetectable (< 0.2 ng/mL) or low (0.21-0.99 ng/mL) at 1-year evaluation. Researchers reviewed laboratory data and neck ultrasound images from the initial assessment and each subsequent follow-up visit. Primary outcome was the rate of ultrasonographic lymph node abnormalities at the 3-year and last follow-up visits.
In patients with undetectable thyroglobulin levels at the 1-year evaluation, researchers observed sonographically suspicious neck lymph nodes in 1.2% of patients at 3 years and in 1.8% at the last visit, for negative predictive values of a 1-year thyroglobulin level of less than 0.2 ng/mL of 98.8% (95% CI, 95.8-99.9%) and 98.2% (95% CI, 95-99.6), respectively.
Among patients with low- or intermediate-risk differentiated thyroid cancer who underwent thyroidectomy, surveillance can safely be based on periodic serum thyroglobulin assays without the routine use of neck ultrasound if the initial imaging assessment reveals no evidence of disease.
Similar negative predictive values emerged for low, detectable 1-year thyroglobulin levels at the 3-year visit (98.2%; 95% CI, 90.3-99.9) and the last visit (94.5%; 95% CI, 84.9-98.9), according to researchers.
Additionally, researchers found that 75% of nodal lesions were likely false-positive; none required treatment. “These findings may provide evidence for more cost-effective follow-up strategies,” Durante said. “Repeated neck ultrasounds may be a source of concern for patients due to the high rate of falsely positive findings, and may reduce the resources for those patients who can benefit the most (ie, the high-risk patients).”
Durante said large-scale, prospective studies involving individuals “falling in the gray area” are needed. “It is still unclear how to manage patients with indeterminate biochemical and/or imaging findings,” Durante said. “Most of these patients are free of disease, but the current diagnostic tools do not allow us to clearly classify these cases as cured.”