TY - JOUR T1 - Complementary Roles of <sup>18</sup>F-DOPA PET/CT and <sup>18</sup>F-FDG PET/CT in Medullary Thyroid Cancer JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 1855 LP - 1863 DO - 10.2967/jnumed.111.094771 VL - 52 IS - 12 AU - Saila Kauhanen AU - Camilla Schalin-Jäntti AU - Marko Seppänen AU - Sami Kajander AU - Sami Virtanen AU - Jukka Schildt AU - Irina Lisinen AU - Aapo Ahonen AU - Ilkka Heiskanen AU - Mika Väisänen AU - Johanna Arola AU - Pirkko Korsoff AU - Tapani Ebeling AU - Timo Sane AU - Heikki Minn AU - Matti J. Välimäki AU - Pirjo Nuutila Y1 - 2011/12/01 UR - http://jnm.snmjournals.org/content/52/12/1855.abstract N2 - Serum calcitonin and carcinoembryonic antigen (CEA) are markers of recurrent or persistent disease in medullary thyroid cancer (MTC). However, conventional imaging often fails to localize metastatic disease. Our aim was to compare fluorine-labeled dihydroxyphenylalanine (18F-DOPA) and 18F-FDG PET/CT with multidetector CT (MDCT) and MRI in recurrent or persistent MTC. Methods: Nineteen MTC patients with increased calcitonin or CEA on follow-up (mean ± SD, 93 ± 91 mo; range, 4–300 mo) after primary therapy were prospectively imaged with 4 techniques: 18F-DOPA PET/CT, 18F-FDG PET/CT, MDCT, and MRI. Images were analyzed for pathologic lesions, which were surgically removed when possible. The correlation between the detection rate for each method and the calcitonin and CEA concentrations and histopathologic findings was investigated. Results: On the basis of histology and follow-up, one or more imaging methods accurately localized metastatic disease in 12 (63%) of 19 patients. The corresponding figures for 18F-DOPA PET/CT, 18F-FDG PET/CT, MDCT, and MRI were 11 (58%) of 19, 10 (53%) of 19, 9 (47%) of 19, and 10 (59%) of 17, respectively. Calcitonin and CEA correlated with 18F-DOPA PET/CT (P = 0.0007 and P = 0.0263, respectively) and 18F-FDG PET/CT findings (both P &lt; 0.0001). In patients with an unstable calcitonin doubling time (n = 8), 18F-DOPA and 18F-FDG PET/CT were equally sensitive. In contrast, for patients with an unstable CEA doubling time (n = 4), 18F-FDG PET/CT was more accurate. Conclusion: For most MTC patients with occult disease, 18F-DOPA PET/CT accurately detects metastases. In patients with an unstable calcitonin level, 18F-DOPA PET/CT and 18F-FDG PET/CT are complementary. For patients with an unstable CEA doubling time, 18F-FDG PET/CT may be more feasible. MRI is sensitive but has the highest rate of false-positive results. ER -