The synergy of 18F-FDG PET/CT and US in the diagnosis of indeterminate thyroid nodules

• 作 者: Lei Jiang Nan Li Yi Zhang Min Zhang Chao Wang Peiyong Li
• 机 构: Department of Nuclear Medicine,Ruijin Hospital,Shanghai Jiaotong University,Shanghai 200025,China
• 出 处: The 1st Sino-American Conference on Nuclear Medicine(首届中美核医学
• 发表日期: 2011年12期
• 关键词: Positron emission tomography/computed tomography (PET/CT) Ultrasound (US) Thyroi

　　Objective: The 18F-FDG accumulated thyroid nodules were found in positron emission tomography (PET) combined with cross-sectional computed tomography (CT) study, and meantime was carried out by ultrasonography (US).Based on the histological results of thyroid nodules, the synergy of 18F-FDG PET/CT and US in the diagnosis of indeterminate thyroid nodules is warranted.Methods: 53 patients with 18F-FDG uptake by indeterminate thyroid nodules were included, 34 males and 19 females with age ranged 33-69 years old.All the patients took US examination 2 weeks before or after 18F-FDG PET.By analyzing the imaging results of these two imaging modalities, the synergy was evaluated on the basis of PET/CT semiquantitative index SUVmax and malignant features of US, including unique or multinodular, size, echo structure, calcification,echogenicity, lymphadenopathy and so on.The clinical diagnosis of the thyroid nodules was confirmed with pathological findings through surgery or puncture.Results: Of 53 patients in this study, thirty two were diagnosed benign and twenty one were malignant.18F-FDG PET/CT found all thyroid cancer patients and US found sixteen of them.PET/CT misdiagnosed ten cases of benign nodules as malignance but US did only one case, while four benign cases were false to detect by US.In this study, the sensitivity and specificity of 18F-FDG PET/CT in detecting and diagnosing malignant thyroid nodules were 100% (21/21) and 68.75% (22/32), and US were 76.19% (16/21) and 96.43% (27/28), respectively.In synergy, if suspected malignant features of US were included into diagnosis criteria of SUVmax≥2.5, the diagnostic accuracy will be increased from 47.73% (21/44) to 57.58% (19/33).Whereas, if SUVmax≥2.5 were included into diagnosis criteria of suspected malignant features of US, the diagnostic accuracy will be arised from 39.02% (16/41) further to 45.71% (16/35).Conclusions: For detecting malignant thyroid nodules, the sensitivity and accuracy of 18F-FDG PET/CT are significantly better than US.The synergy of two modalities helps to increase the diagnostic accuracy of malignant thyroid nodules.