FDG PET is not all that sensitive in neuroendocrine cancers(NET). This may relate to how neuroendocrine cancer takes up FDG in comparison to other radio-labels used for PET scanning. One study revealed that for neuroendocrine tumors, 18F-FDOPA scanning was more sensitive and accurate (sensitivity, 100%; specificity, 91%) in the detection of skeletal lesions than octreotide scintigraphy or CT but was not sensitive (sensitivity, 20%; specificity, 94%) in the lung, ostensibly because of respiratory motion during image acquisition. Octreotide scintigraphy yielded its best results in the liver (sensitivity, 75%; specificity, 100%); however, it was less accurate than FDOPA PET in all organs. However, 18F-FDOPA PET is less sensitive than FDG PET and standard imaging procedures for the staging of small cell lung cancer. Popperl et al recommends that 18F-FDG should be preserved for less differentiated tumors, while amine precursors and somatostatin analogs should be used for PET scanning in the diagnostic process of well-differentiated NET. NCCN on p. MS-12 does not recommend FDG PET.
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