The role of18 F-FDG PET/CT in detecting metastatic deposits of recurrent medullary thyroid carcinoma: A prospective study

• Published in: European journal of surgical oncology Vol. 34; no. 5; pp. 581 - 586
• Main Authors: Rubello, D, Rampin, L, Nanni, C, Banti, E, Ferdeghini, M, Fanti, S, Al-Nahhas, A, Gross, M.D
• Format: Journal Article
• Language: English
• Published: 2007
• Subjects: Hematology, Oncology and Palliative Medicine; Surgery; 111In-pentetreotide scan; 18F-FDG PET/CT; Metastatic medullary thyroid carcinoma (MTC); Serum calcitonin; High resolution neck ultrasound; Contrast enhanced CT
• ISSN: 0748-7983
• DOI: 10.1016/j.ejso.2007.08.005

Abstract Aim To assess the diagnostic role of18 F-FDG PET/CT performed with a hybrid tomograph in the detection of tumoral deposits of recurrent medullary thyroid carcinoma (MTC). Methods Nineteen MTC patients with elevated serum calcitonin levels (58–1350 pg/ml) after first treatment were enrolled (11 F, 8 M, mean age 53.4 years, 14 sporadic MTC, 5 MEN-related MTC). All patients had previously undergone total thyroidectomy and lymphoadenectomy. When referred to us, they were studied with ultrasound (US),18 F-FDG PET/CT,111 In-pentetreotide scan, and contrast-enhanced whole-body CT (c.e. CT). In 4 patients with equivocal abdominal findings at18 F-FDG PET/CT and/or at c.e. CT, laparoscopy was also performed. Results18 F-FGD PET/CT depicted metastases in 15 patients,111 In-pentetreotide in 8, c.e. CT in 11, US in 6. In 2 patients, liver micrometastases were detected at laparoscopy only. At a lesion-by-lesion analysis,18 F-FDG PET/CT visualized a total of 26 metastatic deposits, c.e. CT 18,111 In-pentetreotide 12, US 8. Final diagnosis was obtained by cytological or surgical findings. Four patients with evidence of limited metastatic spread to neck/upper mediastinum were re-operated, and in 2 of them serum calcitonin levels normalized. Conclusions In our study,18 F-FDG PET/CT was the most sensitive imaging modality in detecting metastases in recurrent MTC patients with increased serum calcitonin levels. Moreover,18 F-FDG PET/CT was useful in some patients to plan a more accurate re-operation. From a diagnostic point of view, a multimodality imaging approach is recommended in recurrent MTC, especially based on the combination of c.e. CT and18 F-FDG PET/CT.