Functional imaging of neuroendocrine tumors with combined PET/CT using ⁶⁸Ga‐DOTATATE (DOTA‐DPhe¹,Tyr³‐octreotate) and ¹⁸F‐FDG

Abstract

BACKGROUND. The aim was to assess the relevant distribution of the novel PET tracer 68Ga‐DOTATATE in neuroendocrine tumors (NETs) with combined positron emission tomography / computed tomography (PET/CT) and compare its performance with that of 18F‐FDG PET/CT. METHODS. The imaging findings with 68Ga‐DOTATATE and 18F‐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 68Ga‐DOTATATE PET/CT was 82% (31 of 38) and that of 18F‐FDG PET/CT was 66% (25 of 38). The sensitivity of combined 68Ga‐DOTATATE and 18F‐FDG PET/CT was 92% (35 of 38). There was greater uptake of 68Ga‐DOTATATE than 18F‐FDG in low‐grade NET (median SUV 29 vs 2.9, P < .001). In high‐grade NET there was higher uptake of 18F‐FDG over 68Ga‐DOTATATE (median SUV 11.7 vs 4.4, P = .03). There was a significant correlation with predominant tumor uptake of 68Ga‐DOTATATE or 18F‐FDG and tumor grade on histology (P < .0001). CONCLUSIONS. 68Ga‐DOTATATE PET/CT is a useful novel imaging modality for NETs and is superior to 18F‐FDG for imaging well‐differentiated NET. Functional imaging with both 68Ga‐DOTATATE and 18F‐FDG has potential for a more comprehensive tumor assessment in intermediate‐ and high‐grade tumors. Cancer 2008. ©2008 American Cancer Society.

Comparison of 68Ga-DOTANOC and 68Ga-DOTATATE PET/CT Within Patients with Gastroenteropancreatic Neuroendocrine Tumors

“…There was no significant difference between the 2 tracers in the tumor detection rate of G2 and G3 tumors. Within the literature, there is evidence that somatostatin receptor PET is of limited value in patients with G3 NETs and that 18 F-FDG PET may be more suitable in these cases (18). In our study, however, 68 Ga-DOTATATE and 68 Ga-DOTANOC PET detected significantly more G3 lesions (82% and 90%, respectively) than did 18 F-FDG PET (58%).…”

“…Somatostatin receptor PET has shown promising results in NETs, with a higher lesion detection rate than is achieved with 18 F-fluorodihydroxyphenyl-L-alanine PET, somatostatin receptor SPECT, CT, or MR imaging (10,11,22,23). Currently, 68 Ga-DOTATOC, 68 Ga-DOTATATE, and 68 Ga-DOTANOC are the most established somatostatin receptor PET tracers (13 68 Ga-DOTATATE and 68 Ga-DOTANOC) showed a similar diagnostic accuracy for these tracers for the detection of NETs.…”

“…In all patients with poorly differentiated neuroendocrine carcinoma (G3), additional 18 F-FDG PET/CT scans were obtained using a dedicated PET/CT unit (Discovery ST 16; GE Healthcare) and a standard protocol (18). All scans were performed within 6 wk of one another.…”

The influence of Ki-67 proliferation index on Tc-99m-EDDA-HYNIC-TOC somatostatin receptor scintigraphy in patients with carcinoids

“…Recent years have seen the development of other radiopharmaceuticals suitable for detecting NETs [14][15][16], but under certain circumstances, F-18-FDG PET can also be of diagnostic importance in NET patients with high proliferation index [17][18][19].…”

Nuclear medicine imaging of neuroendocrine tumours

“…A study by Kayani et al 14 of 68 Ga-Dotatate and 18 F-FDG PET/CT in 38 NET patients found a higher sensitivity (88%) for 68 Ga-Dotatate, particularly in welldifferentiated tumours, compared with 18 F-FDG PET/CT (66%). Other PET radiopharmaceuticals were also found to be inferior to 68 Ga-peptides.…”