Abstract
2101
Objectives Neuroendocrine tumours (NETs) are rare tumours originating from the neural crest. Most frequently, NET arise in the gastrointestinal tract, the pancreas, the lung and rarely in other organs. The diagnosis of NET relies on radiological-scintigraphic imaging methods and tumour marker levels.It’s difficult to detect NET by positron emission tomography (PET) with 18F FDG because of low metabolic activity.However, PET using 68Ga DOTA peptides is a promising imaging method in diagnosis and follow-up of NET because NET typically express somatostatin receptor.The aim of this study is to compare the diagnostic efficacy of 68Ga-DOTA-TATE and 18F-FDG PET scintigraphy.
Methods 39 patients (20 men, 19 women, range:11-79 mean age:48 y) with diagnosis of NET who underwent 68Ga-DOTA-TATE and 18F-FDG PET /CT at our institution were enrolled in this study.Maximum interval between the two study was 2 months (median interval: 23 d).The imaging findings were recorded per region in 7 regions (thyroid bed, lymphatic stations, lungs, liver, bones, pancreas and other) for every patient. PET images were evaluated visually.
Results Of 39 patients with NET 15 patients had no uptake; 22 patients had uptake by either modality.On a lesion basis, 68Ga-DOTA-TATE PET detected more lesion than 18F-FDG PET.In 5 patients (12.8%), 68Ga-DOTA-TATE PET was positive but 18F-FDG PET was negative.On the other hand, 3 patients (7.6%) had 18F-FDG positive but 68Ga-DOTA-TATE negative lesions.68Ga-DOTA-TATE PET is found to be superior to 18F-FDG PET for detection of NET (P=0,001).There was significant correlation with FDG SUV and Ki-67 index (r=0,514; p=0,004).The correlation with 68Ga SUV and Ki-67 index was nas statisticaly significant (r=0,181; p=0,338).
Conclusions 68Ga-DOTA-TATE PET/CT is a valuable imaging modality for diagnosis and follow-up of NETs and is superior to 18F-FDG PET/CT.
Research Support Scientific Research Projects Coordination Unit (BAP) of Istanbul University with Project number 3264