Related Experiment Video
Updated: Mar 15, 2026
Computer-Aided Three-Dimensional Visualization in the Treatment of Locally Advanced Thyroid Cancer
Published on: June 9, 2023
Acknowledging gray areas: 2015 vs. 2009 American Thyroid Association differentiated thyroid cancer guidelines on
Savvas Frangos1, Ioannis P Iakovou2, Robert J Marlowe3
1Department of Nuclear Medicine, Bank of Cyprus Oncology Centre, 32 Acropoleos Avenue, Strovolos, Nicosia, 2006, Cyprus. savvas.frangos@gmail.com.
Purpose:
Typically formulated by investigators from "world centres of excellence," differentiated thyroid carcinoma (DTC) management guidelines may have more limited applicability in settings of less expert care and fewer resources. Arguably the world's leading DTC guidelines are those of the American Thyroid Association, revised in 2009 ("ATA 2009") and 2015 ("ATA 2015"). To further explore the issue of "real-world applicability" of DTC guidelines, we retrospectively compared indications for ablation using ATA 2015 versus ATA 2009 in a two-centre cohort of ablated T1-2, M0 DTC patients (N = 336). Based on TNM status and histology, these patients were low-intermediate risk, but many ultimately had other characteristics suggesting elevated or uncertain risk.
Methods:
Working by consensus, two experienced nuclear medicine physicians considered patient and treatment characteristics to classify each case as having "no indication," a "possible indication," or a "clear indication" for ablation according to ATA 2009 or ATA 2015. The physicians also identified reasons for classification changes between ATA 2015 versus ATA 2009. Classification was unblinded, but the physicians had cared for only 138/336 patients, and the charts encompassed September 2010-October 2013, several years before the classification was performed.
Results:
One hundred of 336 patients (29.8 %) changed classification regarding indication for ablation using ATA 2015 versus ATA 2009. Most reclassified patients (70/100) moved from "no indication" or "clear indication" to "possible indication." Reflecting this phenomenon, "possible indication" became the largest category according to the ATA 2015 classification (141/336, 42.0 %, versus 96/336, 28.6 %, according to ATA 2009). Many reclassifications were attributable to multiple clinicopathological characteristics, most commonly, stimulated thyroglobulin or anti-thyroglobulin antibody levels, multifocality, bilateral involvement, or capsular/nodal invasion.
Conclusions:
Regarding indications for ablation, ATA 2015 appears to better "acknowledge grey areas," i.e., patients with ambiguous or unavailable data requiring individualised, nuanced decision-making, than does ATA 2009.
Insights
The 2015 American Thyroid Association guidelines for differentiated thyroid carcinoma (DTC) better address ambiguous cases for ablation therapy compared to the 2009 guidelines. This impacts patient management by acknowledging more "grey areas" in risk assessment.
Area of Science:
- Endocrinology
- Nuclear Medicine
- Oncology
Background:
- Differentiated thyroid carcinoma (DTC) management guidelines, often developed at expert centers, may face challenges in real-world application in resource-limited settings.
- The American Thyroid Association (ATA) guidelines, revised in 2009 (ATA 2009) and 2015 (ATA 2015), are leading international standards for DTC care.
Purpose of the Study:
- To compare the applicability of ATA 2015 versus ATA 2009 guidelines for determining indications for radioactive iodine ablation in DTC patients.
- To evaluate the impact of guideline revisions on patient classification in a real-world clinical setting.
Main Methods:
- A retrospective analysis of 336 patients with ablated T1-2, M0 DTC was conducted.
- Two nuclear medicine physicians classified ablation indications based on ATA 2009 and ATA 2015 criteria, noting changes and reasons for reclassification.
Main Results:
- A significant proportion of patients (100/336, 29.8%) experienced a change in ablation indication classification between ATA 2009 and ATA 2015.
- The ATA 2015 guidelines resulted in more patients classified under "possible indication" (42.0% vs. 28.6%), reflecting increased acknowledgment of ambiguous cases.
- Reclassifications were often driven by factors such as stimulated thyroglobulin levels, tumor multifocality, bilateral disease, or capsular/nodal invasion.
Conclusions:
- The ATA 2015 guidelines demonstrate improved ability to identify and manage "grey areas" in DTC ablation indications compared to ATA 2009.
- These findings suggest the ATA 2015 guidelines offer a more nuanced approach for individualized decision-making in complex DTC cases.
