Clinical Value Of Radionuclide Imaging In Pancreatic Cancer And Ectopic Thyroid

Objective: To evaluate the added value of ¹⁸F-FDG PET/CT in preoperative evaluation of the distant metastases of pancreatic cancer with contrast-enhanced CT?CE-CT?.Methods: Fifty-one patients with pancreatic cancer were retrospectively analyzed. We diagnosed the patients had distant metastases or not by single abdominal CE-CT and abdominal CE-CT combined with PET/CT respectively. Pathology and clinical follow-up was used to confirm the metastases. Finally, the added value of PET/CT was evaluated.Results: The sensitivity, specificity and accuracy of CE-CT, CE-CT combined with PET/CT in determining whether the patients had distant metastases or not were 71.4%?25/35?, 100%?16/16? and 76.5%?41/51?; 94.2%?33/35?, 100%?16/16? and 96.1%?49/51? respectively. The sensitivity and accuracy were significantly improved??2=6.43, P=0.011; ?2=6.04, P=0.014? after abdominal CE-CT combined with PET/CT. Twenty-six patients were diagnosed of no distant metastases by single CE-CT, however, when CE-CT combined with PET/CT, 6 cases with liver metastasis?they were close to the liver capsule with diameter between 6.7⁹.8mm? and 2 cases with lung metastasis were correctly diagnosed. Another 25 cases with distant metastases were all correctly diagnosed by abdominal CE-CT, when abdominal CE-CT combined with PET/CT, the result was not changed.Conclusion: PET/CT provides added value for patients who are diagnosed of pancreatic cancer with no distant metastasis by single CE-CT, PET/CT is especially useful for the patients with small liver lesion?diameter less than 1 cm? close to the liver capsular.Objective: To investigate the value of ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography(¹⁸F-FDG PET/CT) in evaluating candidates for surgery of pancreatic adenocarcinoma and its cost-effectiveness.Methods: A retrospective review of hospital record and cost was performed for 89 patients with biopsy-proven pancreatic adenocarcinoma who underwent contrast-enhanced computed tomography?ce-CT? and ¹⁸F-FDG PET/CT preoperatively. First, we compared the value of ce-CT and ce-CT combined with ¹⁸F-FDG PET/CT in evaluating candidates for surgery of pancreatic adenocarcinoma by ?2 test. Second, we calculated whether ¹⁸F-FDG PET/CT help patients save money [(average cost of pancreatic resection and postoperative day in hospital×number of patients who was evaluated to be non-candidate for surgery by ¹⁸F-FDG PET/CT-cost of ¹⁸F-FDG PET/CT×total number of patients)/ total number of patients]. Finally, we try to make it clear whether more money can be saved if ¹⁸F-FDG PET/CT only used in patients who was evaluated to be candidate for surgery by ce-CT.Results: If all patients received correct therapy according to the results of ce-CT and ¹⁸F-FDG PET/CT, then 36.0%?32/89? and 52.8%?47/89? patients may avoid unnecessary operation by single ce-CT and ce-CT combined with ¹⁸F-FDG PET/CT respectively??2=5.1, P=0.024?. Because of ¹⁸F-FDG PET/CT, ?7877.0 can be saved per patient. Fifty-seven patients were evaluated to be candidates for surgery, however, ¹⁸F-FDG PET/CT made 15 patients avoid unnecessary surgery, ten with liver metastasis, one with lung metastasis, two with peritoneal carcinomatosis and two with distant lymph node metastasis, saving?16228.9 per patient.Conclusion: ¹⁸F-FDG PET/CT is valuable in evaluating the candidates for surgery of pancreatic adenocarcinoma and cost-saving, it is especially valuable in patients who were evaluated to be candidate for surgery by ce-CT.Objective: To investigate the imaging features of ectopic thyroid on computed tomography?CT?, magnetic resonance imaging?MRI?, scintigraphy and single-photon emission?SPECT?/CT.Methods: Fifteen benign ectopic thyroid masses in 12 patients?11 women and 1man? aged 7-61 years were retrospectively analyzed. Eleven patients?thirteen masses? underwent unenhanced and contrast-enhanced CT, four patients?six masses? underwent unenhanced and contrast-enhanced MRI, twelve patients?15 masses? underwent scintigraphy and three patients?three masses? underwent SPECT/CT.Results: Of the 12 patients, solitary lingual, sublingual and prelaryngeal ectopic thyroid mass was observed in two, six and one patient respectively, dual ectopic thyroid masses were observed in another three patients. Most of them?91.7%, 11/12? did not have a normal cervical thyroid. Of the 15 ectopic thyroid masses, they all presented with an ovoid shape, well-defined margin, and hyper-density?n=12? or slight hyper-density?n=1? on unenhanced CT, iso-intensity?n=5? or slight hyper-intensity?n=1? on T1-weighted images, iso-intensity?n=3? or slight hyper-intensity?n=3? on T2-weighted images, and marked homogeneous?n=4? or heterogeneous?n=9? enhancement on contrast-enhanced CT, poor?n=5? or moderate?n=1? heterogeneous enhancement on enhanced T1-weighted image. All of the 15 ectopic thyroid masses took up tracer?99mTc O4–or 131I?, however, one mass was equivocal on scintigraphy with 99 mTcO4–, focal and diffused tracer uptake were observed in two and one mass on the images of SPECT/CT.Conclusion: Ectopic thyroid most commonly present with a lingual or sublingual mass in females with absence of a normal cervical thyroid. An ovoid, well-defined mass with hyperdensity, marked enhancement on CT, iso-intensity or slight hyperintensity on T1 WI or T2 WI is suggestive of this diagnosis. Ectopic thyroid mass may be equivocal on scintigraphy with 99 mTcO4–, and may has non-functional regions.