Abstract
PurposeTo assess the impact of an [18F]FDG-PET/CT-driven diagnostic workup to rule out malignancy, avoid futile diagnostic surgeries, and improve patient outcomes in thyroid nodules with indeterminate cytology.MethodsIn this double-blinded, randomised controlled multicentre trial, 132 adult euthyroid patients with scheduled diagnostic surgery for a Bethesda III or IV thyroid nodule underwent [18F]FDG-PET/CT and were randomised to an [18F]FDG-PET/CT-driven or diagnostic surgery group. In the [18F]FDG-PET/CT-driven group, management was based on the [18F]FDG-PET/CT result: when the index nodule was visually [18F]FDG-positive, diagnostic surgery was advised; when [18F]FDG-negative, active surveillance was recommended. The nodule was presumed benign when it remained unchanged on ultrasound surveillance. In the diagnostic surgery group, all patients were advised to proceed to the scheduled surgery, according to current guidelines. The primary outcome was the fraction of unbeneficial patient management in one year, i.e., diagnostic surgery for benign nodules and active surveillance for malignant/borderline nodules. Intention-to-treat analysis was performed. Subgroup analyses were performed for non-Hürthle cell and Hürthle cell nodules.ResultsPatient management was unbeneficial in 42% (38/91 [95% confidence interval [CI], 32–53%]) of patients in the [18F]FDG-PET/CT-driven group, as compared to 83% (34/41 [95% CI, 68–93%]) in the diagnostic surgery group (p < 0.001). [18F]FDG-PET/CT-driven management avoided 40% (25/63 [95% CI, 28–53%]) diagnostic surgeries for benign nodules: 48% (23/48 [95% CI, 33–63%]) in non-Hürthle cell and 13% (2/15 [95% CI, 2–40%]) in Hürthle cell nodules (p = 0.02). No malignant or borderline tumours were observed in patients under surveillance. Sensitivity, specificity, negative and positive predictive value, and benign call rate (95% CI) of [18F]FDG-PET/CT were 94.1% (80.3–99.3%), 39.8% (30.0–50.2%), 95.1% (83.5–99.4%), 35.2% (25.4–45.9%), and 31.1% (23.3–39.7%), respectively.ConclusionAn [18F]FDG-PET/CT-driven diagnostic workup of indeterminate thyroid nodules leads to practice changing management, accurately and oncologically safely reducing futile surgeries by 40%. For optimal therapeutic yield, application should be limited to non-Hürthle cell nodules.Trial registration numberThis trial is registered with ClinicalTrials.gov: NCT02208544 (5 August 2014), https://clinicaltrials.gov/ct2/show/NCT02208544.
Highlights
Thyroid nodules are common, but seldom harbour malignancy [1, 2]
Ultrasonography and fine needle aspiration cytology (FNAC) adequately differentiate benign from malignant thyroid nodules in approximately 70% of patients, but diagnostic dilemmas remain for nodules with indeterminate cytology, including atypia of undetermined significance or follicular lesion of undetermined
Adult euthyroid patients in whom diagnostic surgery was scheduled for an indeterminate thyroid nodule, defined as Bethesda III or Bethesda IV cytology, were eligible for study participation [3]
Summary
But seldom harbour malignancy [1, 2]. Ultrasonography and fine needle aspiration cytology (FNAC) adequately differentiate benign from malignant thyroid nodules in approximately 70% of patients, but diagnostic dilemmas remain for nodules with indeterminate cytology, including atypia of undetermined significance or follicular lesion of undetermined1 3 Vol.:(0123456789)European Journal of Nuclear Medicine and Molecular Imaging significance (Bethesda III, AUS/FLUS) and (suspicious for a) follicular neoplasm (Bethesda IV, FN/SFN) or Hürthle cell neoplasm (Bethesda IV, HCN/SHCN) [2, 3]. But seldom harbour malignancy [1, 2]. Ultrasonography and fine needle aspiration cytology (FNAC) adequately differentiate benign from malignant thyroid nodules in approximately 70% of patients, but diagnostic dilemmas remain for nodules with indeterminate cytology, including atypia of undetermined significance or follicular lesion of undetermined. The follicular lesions of which this group largely consists require histopathological assessment of capsular and vascular invasion to obtain a conclusive benign or malignant diagnosis [3]. When diagnostic surgery is performed, a mere one in four indeterminate thyroid nodules harbours malignancy. A more accurate preoperative differentiation is needed to avoid futile diagnostic surgeries for benign nodules
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: European Journal of Nuclear Medicine and Molecular Imaging
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
