Although the prognosis of patients with differentiated thyroid carcinoma (DTC) is generally encouraging, a diagnostic dilemma is posed when an increasing level of serum thyroglobulin (Tg) is noted, without detection of a recurrent tumor using conventional imaging tools such as the iodine-131 whole-body scanning (the [131I] scan) or neck ultrasonography (US). The objective of the present study was to evaluate the diagnostic value of [124I]-PET/CT and [18F]-FDG-PET/CT in terms of accurate detection of both iodine- and non-iodine-avid recurrence, compared with that of conventional imaging such as the [131I] scan or neck ultrasonography (US). Between July 2009 and June 2010, we prospectively studied 19 DTC patients with elevated thyroglobulin levels but who do not show pathological lesions when conventional imaging modalities are used. All involved patients had undergone total thyroidectomy and radioiodine (RI) treatment, and who had been followed-up for a mean of 13 months (range, 6-21 months) after the last RI session. Combined [18F]-FDG-PET/CT and [124I]-PET/CT data were evaluated for detecting recurrent DTC lesions in study patients and compared with those of other radiological and/or cytological investigations. Nine of 19 patients (47.4%) showed pathological [18F]-FDG (5/19, 26.3%) or [124I]-PET (4/19, 21.1%) uptake, and were classed as true-positives. Among such patients, disease management was modified in six (66.7%) and disease was restaged in seven (77.8%). In particular, the use of the described imaging combination optimized planning of surgical resection to deal with locoregional recurrence in 21.1% (4/19) of patients, who were shown to be disease-free during follow-up after surgery. Our results indicate that combination of [18F]-FDG-PET/CT and [124I]-PET/CT affords a valuable diagnostic method that can be used to make therapeutic decisions in patients with DTC who are tumor-free on conventional imaging studies but who have high Tg levels.
Adult ; Aged ; Aged, 80 and over ; Carcinoma/metabolism/*radionuclide imaging/surgery ; Female ; Fluorodeoxyglucose F18/chemistry/diagnostic use ; Follow-Up Studies ; Humans ; Iodine Radioisotopes/chemistry/diagnostic use ; Male ; Middle Aged ; Neck/ultrasonography ; Positron-Emission Tomography and Computed Tomography ; Prospective Studies ; Radiopharmaceuticals/chemistry/*diagnostic use ; Recurrence ; Thyroglobulin/blood ; Thyroid Neoplasms/metabolism/*radionuclide imaging/surgery ; Thyroidectomy ; Whole Body Imaging

Carcinoid tumors of the duodenum are infrequent, represent 2.0-3.0% of all gastrointestinal carcinoid tumors in western countries and 14.8% of those in Japan. Small carcinoid tumors of the duodenum are often asymptomatic, discovered endoscopically, Duodenal carcinoid tumors have been treated by surgical resection or endoscopic resection with strip biopsy or polypectomy. We experience a case of carcinoid tumor of duodenum in 49 years woman. Endoscopic examination, 0.7 cm sized polypoid mass with central depression was noted on duodenal bulb area. We present a case of a small duodenal carcinoid treated with strip biopsy technique.
Biopsy* ; Carcinoid Tumor* ; Depression ; Duodenum ; Female ; Humans ; Japan