title: Detection rate of recurrent medullary thyroid carcinoma using fluorine-18 fluorodeoxyglucose positron emission tomography: a meta-analysis.
abstract: Several studies evaluated the diagnostic performance of fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET), and positron emission tomography/computed tomography (PET/CT) in detecting recurrent medullary thyroid carcinoma (MTC) with conflicting results. Aim of our study is to meta-analyze published data about this topic. A comprehensive computer literature search of studies published in PubMed/MEDLINE, Scopus, and Embase databases through December 2011 and regarding FDG PET or PET/CT in patients with suspected recurrent MTC was carried out. Pooled detection rate (DR) on a per patient-based analysis was calculated to measure the diagnostic performance of FDG PET and PET/CT in this setting. A sub-analysis considering PET device used, serum calcitonin, carcino-embryonic antigen (CEA), calcitonin doubling time (CTDT), and CEA doubling time (CEADT) values was also performed. Twenty-four studies comprising 538 patients with suspected recurrent MTC were included. DR of FDG PET or PET/CT in suspected recurrent MTC on a per patient-based analysis was 59 % (95 % confidence interval: 54-63 %). Heterogeneity between the studies was revealed. DR increased in patients with serum calcitonin ≥ 1,000 ng/L (75 %), CEA ≥ 5 ng/ml (69 %), CTDT <12 months (76 %), and CEADT <24 months (91 %). In patients with suspected recurrent MTC FDG PET and PET/CT are associated with a non-optimal DR since about 40 % of suspected recurrent MTC remain usually unidentified. However, FDG PET and PET/CT could modify the patient management in a certain number of recurrent MTC because these methods are often performed after negative conventional imaging studies. DR of FDG PET and PET/CT increases in patients with higher calcitonin and CEA values and lower CTDT and CEADT values, suggesting that these imaging methods could be very helpful in patients with more aggressive disease.
authors.affiliation: Institute of Nuclear Medicine, Catholic University of Sacred Heart, Largo Gemelli, 8, 00168, Rome, Italy. giorgiomednuc@libero.it
authors.forename: Giorgio
authors.initials: G
authors.lastname: Treglia
authors.forename: Maria Felicia
authors.initials: MF
authors.lastname: Villani
authors.forename: Alessandro
authors.initials: A
authors.lastname: Giordano
authors.forename: Vittoria
authors.initials: V
authors.lastname: Rufini
mesh_terms: D018276:Carcinoma, Medullary / Q000000981:diagnostic imaging; D018278:Carcinoma, Neuroendocrine; D019788:Fluorodeoxyglucose F18; D006801:Humans; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging*
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18