Comparison of Different Positron Emission Tomography Tracers in Patients with Recurrent Medullary Thyroid Carcinoma: Our Experience and a Review of the Literature Giorgio Treglia, Paola Castaldi, Maria Felicia Villani, Germano Perotti, Angelina Filice, Valentina Ambrosini, Nadia Cremonini, Annibale Versari, Stefano Fanti, Alessandro Giordano and Vittoria Rufini Abstract Several morphological and functional imaging techniques are usually used to detect residual/recurrent medullary thyroid carcinoma (MTC) with variable results; currently, there is growing interest in positron emission tomography (PET) methodology. Herein, we report our experience of and a literature review about the comparison of different positron emission tomography (PET) tracers in patients with residual/recurrent MTC. 18 F-DOPA PET/CT seems to be the most useful imaging method to detect recurrent MTC lesions, performing better than 18 F-FDG and 68 Ga-somatostatin analogs PET/CT. 18 F-FDG may comple- ment 18 F-DOPA in patients with aggressive tumors. 68 Ga-somatostatin analogs PET/CT may be useful to select patients who could benefit from radioreceptor therapy. The information provided by the various PET tracers reflects different metabolic pathways, and may help to select the most appropriate treatment. G. Treglia (&) Á P. Castaldi Á M. F. Villani Á G. Perotti Á A. Giordano Á V. Rufini Institute of Nuclear Medicine, Catholic University of the Sacred Heart, Largo Gemelli 8, 00168 Rome, Italy e-mail: giorgiomednuc@libero.it A. Filice Á A. Versari Nuclear Medicine Unit, Santa Maria Nuova Hospital, Reggio Emilia, Italy V. Ambrosini Á S. Fanti Nuclear Medicine Unit, Sant’Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy N. Cremonini Unit of Endocrinology, Ospedale Maggiore, Bologna, Italy R. P. Baum and F. Rösch (eds.), Theranostics, Gallium-68, and Other Radionuclides, Recent Results in Cancer Research 194, DOI: 10.1007/978-3-642-27994-2_21, Ó Springer-Verlag Berlin Heidelberg 2013 385