Role of [18F]FDG-PET/CT in the detection of occult recurrent medullary thyroid cancer

Abstract

[(18)F]FDG-PET/CT seems to be valuable for the detection of recurrence in patients with highly elevated calcitonin levels and negative conventional imaging findings. In addition, it seems that the sensitivity of [(18)F]FDG-PET/CT may be higher in patients with sporadic or familial MTC than in patients with MTC as part of multiple endocrine neoplasia type IIA syndrome.

Comparison of 18F-DOPA, 18F-FDG and 68Ga-somatostatin analogue PET/CT in patients with recurrent medullary thyroid carcinoma

“…A possible explanation for this low 18 F-FDG PET/CT sensitivity (17%) in our series when compared to those reported in the literature (30-95%) could be related to the significant number of MTC [8,9,11,[13][14][15][23][24][25][26][27][28][29][30][31][32][33]. Nevertheless, 18 F-FDG PET/CT may provide useful information in patients with more aggressive disease, as demonstrated in patient 4 in whom it detected multiple liver lesions that were missed on functional PET/CT with the other two tracers, as well as two additional locoregional lymph nodes.…”

How has the management of medullary thyroid carcinoma changed with the advent of 18F-FDG and non-18F-FDG PET radiopharmaceuticals

“…However, given the heterogeneity of MTC phenotypic expression, 18 F-FDG PET may be best suited to detect only a small subset of biologically aggressive tumors that overexpress glucose transporter proteins [18]. Other novel non-18 F-FDG positron-emitting radiopharmaceuticals such as 18 F-fluorodihydroxyphenylalanine ( 18 F-DOPA) and 68 Ga-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) somatostatin analogues have been used to successfully image a wide variety of NETs, including MTC, and several studies have demonstrated superior sensitivity compared with 18 F-FDG PET for detection of MTC.…”

“Atypical” Non-Secretory Medullary Thyroid Carcinoma: Case Report and Review of the Literature

“…The follow up of these patients is more difficult, since serum calcitonin is of no use. Most authors suggest a neck ultra sound, an x-ray or CT of the thorax, an ultra sound or MRI of the liver, and measurements of serum calcitonin and CEA [10,15] , upon follow up, and if needed [18F] FDG-PET/CT [15,17]. Of course if a RET mutation is discovered the follow up must include evaluation of PTH and catecholamines/ metanephrines.…”