Radioactive Iodine in Differentiated Thyroid Carcinoma: A Systematic AGREE II Clinical Practice Guideline Appraisal

Objective: Identify and appraise clinical practice guidelines (CPGs) for radioactive iodine (RAI) indications in differentiated thyroid carcinoma (DTC), and the treatment for radioactive iodine refractory (RAI-R) DTC using the Appraisal of Guidelines for Research and Evaluation II tool. Data Sources: MEDLINE (Pubmed), Ovid (EMBASE), and Scopus. Review Methods: A systematic literature search was conducted to identify CPGs addressing RAI in DTC. CPGs were appraised by 4 independent reviewers in 6 distinct areas of quality. Scaled domain scores were subsequently calculated for each domain. Intraclass correlation coefficients were calculated for each domain to assess interrater reliability. Results: Sixteen guidelines were found addressing RAI indications for DTC. Of these 16, 9 also addressed the treatment of RAI-R DTC. A further 6 unique guidelines were identified that exclusively address RAI-R DTC, bringing the total number of guidelines to 22. The American Thyroid Association (ATA) guidelines for adult thyroid cancer were the highest scoring with a mean score of 83.5%. Two guidelines scored >60% in 5 or more domains, qualifying as “high” quality: ATA and British Thyroid Association. The highest scoring domain was domain 4: clarity of presentation (80.4%) while the lowest scoring domain was domain 5: applicability (38.6%). Conclusion: Of the 22 guidelines identified, only two were “high quality.” CPGs exclusively addressing the treatment of RAI-R DTC were weak with most guidelines scoring in the “low” quality range. This report reveals an unmet need for rigorously developed guidelines addressing indications for RAI in DTC, as well as the treatment for RAI-R DTC.