However, [sup.18]F-FDG showed no difference between pancreatic and gastrointestinal NENs in terms of sensitivity.
[sup.68]Ga-DOTATATE and [sup.18]F-FDG PET/CT play a crucial role in the diagnosis and clinical management of NENs with morphologic and functional information.
[sup.68]Ga-DOTATATE imaging and [sup.18]F-FDG PET/CT imaging have been compared in several studies which have been shown to have variable sensitivities in detecting NENs with a relatively small number of patients.
[SUV.sub.max] of PET/CT maybe a suitable biomarker for evaluation of the biological behavior of NENs. The relationship between [SUV.sub.T/L] and Ki-67 index was weak, but it showed a consistency with [SUV.sub.max].
The nomenclature and classification of NENs have always been a dispute, which are lack of uniform standard.
However, the impact of tumor location on the outcome of colorectal NENs remains controversial.
And the research about colorectal NENs is rare because of the low incidence.
A total of 68 colorectal NENs patients who were treated in the Second Affiliated Hospital, Zhejiang University School of Medicine, between March 2001 and March 2014 were included in this retrospective study.
The major change in the new WHO classification (2010)  is a new approach in coding of NENs according to ICDO3.
In our opinion, diagnostic process of NENs should be performed in close cooperation with the clinicians, especially oncologists.
The results of our study demonstrate the frequency of individual types of GEP-NENs in routine bioptic examinations and appearance of NENs in different sites of origin within the GIT.
 Nonstandard abbreviations: NEN
, neuroendocrine neoplasia; CgA, chromogranin A; CgB, chromogranin B; CART, cocaine- and amphetamineregulated transcript; CKD, chronic kidney disease; IR, immunoreactivity; CgA-IR, CgA as measured by IR; eGFR, estimated glomerular filtration rate.