Tumor Biol. DOI 10.1007/s13277-014-1813-4
RESEARCH ARTICLE
Risk of malignancy in focal thyroid lesions identified by 18F-fluorodeoxyglucose positron emission tomography or positron emission tomography/computed tomography: evidence from a large series of studies Ning Qu & Ling Zhang & Zhong-wu Lu & Wen-jun Wei & Yan Zhang & Qing-hai Ji
Received: 11 December 2013 / Accepted: 28 February 2014 # International Society of Oncology and BioMarkers (ISOBM) 2014
Abstract Focal thyroid incidentaloma identified on 18Ffluorodeoxyglucose positron emission tomography or positron emission tomography/computed tomography (18F-FDG PET or PET/CT) indicates a high risk of thyroid malignancy. A metaanalysis was performed to investigate whether the maximum standardized uptake value (SUVmax) could discriminate between benign and malignant tissues in focal lesions and to explore the cutoff value of SUVmax for the diagnosis of malignancy. A total of 29 studies were involved in this metaanalysis. The results indicated that there was no statistically significant difference in the size of the two benign and malignant groups when measured by ultrasonography (95 % confidence interval (CI), −0.79 to 0.03 min; p=0.07), while a significantly higher focal SUVmax was observed in the malignant group (95 % CI, 0.34 to 1.05; p=0.0001). In conclusion, the findings of this meta-analysis suggest that a higher focal 18 F-FDG SUVmax was associated with a higher risk of thyroid malignancy, especially at a threshold of 3.3 or more. Keywords Thyroid . Incidentaloma . PET . PET/CT . F-FDG . Meta-analysis
Introduction
emission tomography or positron emission tomography/ computed tomography (18F-FDG PET or PET/CT), have been considered as an issue in clinical practice [1–6]. 18F-FDG PET or PET/CT is a noninvasive whole-body imaging technique [7] with the potential to better distinguish malignant incidentalomas from benign incidentalomas via metabolic imaging [8], which might spare patients from undergoing unnecessary testing and surgical resection. Focally increased 18F-FDG uptake in the thyroid has been associated with a high rate of clinically relevant malignancies [2, 9–13]. Although a significant difference in the maximum standardized uptake value (SUVmax) between benign and malignant focal thyroid lesions has been observed, it is still difficult to determine whether the SUVmax can distinguish malignant focal thyroid nodules from benign ones; in addition, no SUVmax cutoff can be considered safe to discriminate between them. Many studies are currently available in the literature investigating the significance of SUVmax as a semiquantitative indicator [12, 14–16]. Thus, the present meta analysis had the following aims: firstly, to review studies dealing with the risk of malignancy in focal incidental findings in the thyroid gland by 18 F-FDG PET or PET/CT imaging and to assess the SUVmax as a potential predictor of a malignant focal lesions; secondly, to explore a cutoff value of SUVmax that distinguishes malignant lesions from benign; and lastly, to evaluate the shortcomings and limitations of the SUVmax as a potential predictor.
Thyroid incidentalomas, defined as focal thyroid lesions encountered during imaging with 18F-fluorodeoxyglucose positron Ning Qu and Ling Zhang contributed equally to this work. N. Qu : L. Zhang : Z.
RESEARCH ARTICLE
Risk of malignancy in focal thyroid lesions identified by 18F-fluorodeoxyglucose positron emission tomography or positron emission tomography/computed tomography: evidence from a large series of studies Ning Qu & Ling Zhang & Zhong-wu Lu & Wen-jun Wei & Yan Zhang & Qing-hai Ji
Received: 11 December 2013 / Accepted: 28 February 2014 # International Society of Oncology and BioMarkers (ISOBM) 2014
Abstract Focal thyroid incidentaloma identified on 18Ffluorodeoxyglucose positron emission tomography or positron emission tomography/computed tomography (18F-FDG PET or PET/CT) indicates a high risk of thyroid malignancy. A metaanalysis was performed to investigate whether the maximum standardized uptake value (SUVmax) could discriminate between benign and malignant tissues in focal lesions and to explore the cutoff value of SUVmax for the diagnosis of malignancy. A total of 29 studies were involved in this metaanalysis. The results indicated that there was no statistically significant difference in the size of the two benign and malignant groups when measured by ultrasonography (95 % confidence interval (CI), −0.79 to 0.03 min; p=0.07), while a significantly higher focal SUVmax was observed in the malignant group (95 % CI, 0.34 to 1.05; p=0.0001). In conclusion, the findings of this meta-analysis suggest that a higher focal 18 F-FDG SUVmax was associated with a higher risk of thyroid malignancy, especially at a threshold of 3.3 or more. Keywords Thyroid . Incidentaloma . PET . PET/CT . F-FDG . Meta-analysis
Introduction
emission tomography or positron emission tomography/ computed tomography (18F-FDG PET or PET/CT), have been considered as an issue in clinical practice [1–6]. 18F-FDG PET or PET/CT is a noninvasive whole-body imaging technique [7] with the potential to better distinguish malignant incidentalomas from benign incidentalomas via metabolic imaging [8], which might spare patients from undergoing unnecessary testing and surgical resection. Focally increased 18F-FDG uptake in the thyroid has been associated with a high rate of clinically relevant malignancies [2, 9–13]. Although a significant difference in the maximum standardized uptake value (SUVmax) between benign and malignant focal thyroid lesions has been observed, it is still difficult to determine whether the SUVmax can distinguish malignant focal thyroid nodules from benign ones; in addition, no SUVmax cutoff can be considered safe to discriminate between them. Many studies are currently available in the literature investigating the significance of SUVmax as a semiquantitative indicator [12, 14–16]. Thus, the present meta analysis had the following aims: firstly, to review studies dealing with the risk of malignancy in focal incidental findings in the thyroid gland by 18 F-FDG PET or PET/CT imaging and to assess the SUVmax as a potential predictor of a malignant focal lesions; secondly, to explore a cutoff value of SUVmax that distinguishes malignant lesions from benign; and lastly, to evaluate the shortcomings and limitations of the SUVmax as a potential predictor.
Thyroid incidentalomas, defined as focal thyroid lesions encountered during imaging with 18F-fluorodeoxyglucose positron Ning Qu and Ling Zhang contributed equally to this work. N. Qu : L. Zhang : Z.
