Gastro-entero-pancreatic neuroendocrine tumors: Is now time for a new approach?

Table 1 Indirect comparison between studies investigating in the role of dual positron emission tomography/computed tomography

Ref.	Type of study	Patients enrolled	Sensitivity in detection of liver metastasis	Sensitivity in detection of lympho-node metastasis	Sensitivity in detection of bone metastasis	Relationship between grading and PET/CT positivity	Impact of dual PET/CT on therapeutic decision
Naswa et al[9]	Retrospective study	51 GEP-NETs	No statistical differences between 68Ga and 18F-FDG	68Ga was superior to 18F-FDG (P < 0.003)	No statistical differences between 68Ga and 18F-FDG	No data	Dual PET/CT helped in selecting therapies
Has Simsek et al[10]	Prospective study	27 GEP-NETs: 10 G1 17 G2	68Ga: 95% 18F-FDG: 40%	68Ga: 95% 18F-FDG: 28%	68Ga: 90% 18F-FDG: 28%	In 74% of patients, 68Ga predominated in patients with lower Ki-67 index, while 18F-FDG in higer ki-67 index GEP-NETs	Dual PET/CT influenced treatment decision in 59% of cases
Partelli et al[11]	Retrospective, bi-institutional study	49 P-NETs	18F-FDG: Described 1 false negative	No data	18F-FDG: described 1 false negative	Median Ki-67 for 68Ga positive tumors: 7%. Median Ki-67 for both 68Ga and 18F- FDG positive tumors: 10% (P = 0.130)	No significant differences

GEP-NETs: Gastroenteropancreatic neuroendocrine tumors; P-NETs: Pancreatic neuroendocrine tumors; 18F-FDG: 18F-fluorodeoxyglucose; PET/CT: Positron emission tomography/computed tomography.

Table 2 Comparison between 68Ga-DOTATATE and 18F-fluorodeoxyglucose positron emission tomography/computed tomography sensitivity in neuroendocrine neoplasms

Ref.	68Ga-DOTATATE PET/CT	18F-FDG PET/CT
Kayani et al[13]	Sensitivity 82%	Sensitivity 66%
Kayani et al[14]	Sensitivity 100%	Sensitivity 54%
Conry et al[15]	Sensitivity 72%	Sensitivity 78%

18F-FDG PET/CT: 18F-fluorodeoxyglucose positron emission tomography/computed tomography.