Functional imaging of neuroendocrine tumors with combined PET/CT using 68Ga-DOTATATE (DOTA-DPhe1,Tyr3-octreotate) and 18F-FDG.
BACKGROUND
The aim was to assess the relevant distribution of the novel PET tracer (68)Ga-DOTATATE in neuroendocrine tumors (NETs) with combined positron emission tomography / computed tomography (PET/CT) and compare its performance with that of (18)F-FDG PET/CT.


METHODS
The imaging findings with (68)Ga-DOTATATE and (18)F-FDG on 38 consecutive patients with a diagnosis of primary or recurrent NET were compared and correlated with tumor grade on histology based on ki67 and mitotic index.


RESULTS
The sensitivity of (68)Ga-DOTATATE PET/CT was 82% (31 of 38) and that of (18)F-FDG PET/CT was 66% (25 of 38). The sensitivity of combined (68)Ga-DOTATATE and (18)F-FDG PET/CT was 92% (35 of 38). There was greater uptake of (68)Ga-DOTATATE than (18)F-FDG in low-grade NET (median SUV 29 vs 2.9, P < .001). In high-grade NET there was higher uptake of (18)F-FDG over (68)Ga-DOTATATE (median SUV 11.7 vs 4.4, P = .03). There was a significant correlation with predominant tumor uptake of (68)Ga-DOTATATE or (18)F-FDG and tumor grade on histology (P < .0001).


CONCLUSIONS
(68)Ga-DOTATATE PET/CT is a useful novel imaging modality for NETs and is superior to (18)F-FDG for imaging well-differentiated NET. Functional imaging with both (68)Ga-DOTATATE and (18)F-FDG has potential for a more comprehensive tumor assessment in intermediate- and high-grade tumors.
Kayani
Irfan
I
Institute of Nuclear Medicine, University College Hospital, London, UK.
Bomanji
Jamshed B
JB
Groves
Ashley
A
Conway
Gerard
G
Gacinovic
Sveto
S
Win
Thida
T
Dickson
John
J
Caplin
Martyn
M
Ell
Peter Joseph
PJ
D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D019788:Fluorodeoxyglucose F18; D005708:Gallium; D006801:Humans; D008297:Male; D008875:Middle Aged; D018358:Neuroendocrine Tumors / Q000000981:diagnostic imaging*; D009942:Organometallic Compounds; D049268:Positron-Emission Tomography; D011379:Prognosis; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D015996:Survival Rate; D014057:Tomography, X-Ray Computed
D009942:Organometallic Compounds; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; C513399:gallium Ga 68 dotatate; D005708:Gallium