FDG-PET/CT in indeterminate thyroid nodules: cost-utility analysis alongside a randomised controlled trial

Purpose To evaluate cost-effectiveness of an [F-1(8)]FDG-PET/CT-driven diagnostic workup as compared to diagnostic surgery, for thyroid nodules with Bethesda III/IV cytology. [F-1(8)]FDG-PET/CT avoids 40% of futile diagnostic surgeries for benign Bethesda III/IV nodules.Methods Lifelong societal costs and quality-adjusted life years (QALYs) were assessed for 132 patients participating in a randomised controlled multicentre trial comparing [F-18]FDG-PET/CT to diagnostic surgery. The observed 1-year trial results were extrapolated using a Markov model. The probability of cost-effectiveness was estimated using cost-effectiveness acceptability curves, taking uncertainty about sampling, imputation, and parameters into account.Results The observed 1-year cost difference of [F-18]FDG-PET/CT as compared to diagnostic surgery was - (sic)1000 (95% CI: - (sic)2100 to CO) for thyroid nodule-related care (p = 0.06). From the broader societal perspective, the 1-year difference in total societal costs was - (sic)4500 (- (sic)9200 to (sic)150) (p = 0.06). Over the modelled lifelong period, the cost difference was - (sic)9900 (- C23,100 to (sic)3200) (p =0.14). The difference in QALYs was 0.019 (- 0.045 to 0.083) at 1 year (p =0.57) and 0.402 (- 0.581 to 1.385) over the lifelong period (p =0.42). For a willingness to pay of (sic)50,000 per QALY, an [F-18] FDG-PET/CT-driven work-up was the cost-effective strategy with 84% certainty.Conclusion Following the observed reduction in diagnostic surgery, an [F-18]FDG-PET/CT-driven diagnostic workup reduced the 1-year thyroid nodule-related and societal costs while sustaining quality of life. It is very likely cost-effective as compared to diagnostic surgery for Bethesda III/IV nodules.