Direct comparison of 68Ga-DOTA-TOC and 18F-FDG PET/CT in the follow-up of patients with neuroendocrine tumour treated with the first full peptide receptor radionuclide therapy cycle

Peptide receptor radionuclide therapy (PRRT) has been recognized as a promising therapy against neuroendocrine tumors (NETs). The use of 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) in NETs has been a matter of controversy. The purpose of this study was to evaluate the long-term survival and efficacy of a second PRRT course with 177Lu-DOTATE in patients with advanced gastroenteropancreatic (GEP) NETs. Furthermore, the value of 18F-FDG PET/CT in these patients was evaluated. 40 patients with GEP NETs who underwent two PRRT courses with 177Lu-DOTATATE and combined examinations with 68Ga-DOTA-TOC and 18F-FDG PET/CT were evaluated. After the second PRRT course, two patients (5.0%) were in partial remission, 21 patients (52.5%) in stable disease and 17 patients (42.5%) had progressive disease. The median overall survival was 122.10 months. After the second PRRT course, the median overall survival was significantly higher (p = 0.033) in the 18F-FDG-negative group compared to the 18F-FDG-positive group (145.50 versus 95.06 months, respectively). The median time to progression was 19.37 months. In conclusion, a second PRRT course with 177Lu-DOTATE is an effective treatment approach for GEP NET patients with disease progression. A change in 18F-FDG status after PRRT may predict the disease course and survival. Patients who are 18F-FDG-negative have a significantly longer overall survival than those who are 18F-FDG-positive.

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Effect of Peptide Receptor Radionuclide Therapy on Somatostatin Receptor Status and Glucose Metabolism in Neuroendocrine Tumors: Intraindividual Comparison of Ga-68 DOTANOC PET/CT and F-18 FDG PET/CT

International Journal of Molecular Imaging ◽

10.1155/2011/524130 ◽

2011 ◽

Vol 2011 ◽

pp. 1-7 ◽

Cited By ~ 18

Author(s):

Sowon Oh ◽

Vikas Prasad ◽

Dong Soo Lee ◽

R. P. Baum

Keyword(s):

Glucose Metabolism ◽

Neuroendocrine Tumors ◽

Fdg Pet ◽

Radionuclide Therapy ◽

Somatostatin Receptor ◽

Peptide Receptor Radionuclide Therapy ◽

Receptor Expression ◽

Peptide Receptor ◽

Pet Ct ◽

Fdg Pet Ct

The heterogeneous nature of the neuroendocrine tumors (NET) makes it challenging to find one uniformly applicable management protocol which is especially true for diagnosis. The discovery of the overexpression of somatostatin receptors (SMS-R) on neuroendocrine tumor cells lead to the generalized and rapid acceptance of radiolabeled somatostatin receptor analogs for staging and restaging of NET as well as for Peptide Receptor Radionuclide Therapy (PRRNT) using Y-90 and Lu-177 DOTATATE/DOTATOC. In this present work we tried to look in to the effect of PRRNT on the glucose metabolism assessed by F-18 FDG PET/CT and SMS-R density assessed by Ga-68 DOTANOC PET/CT. We observed a complex relationship between the somatostatin receptor expression and glucose metabolism with only 56% (77/138) of the lesions showing match, while the others show mismatch between the receptor status and metabolism. The match between receptor expression and glucose metabolism increases with the grade of NET. In grade 3 NET, there is a concurrence between the changes in glucose metabolism and somatostatin receptor expression. PRRNT was found to be more effective in lesions with higher receptor expression.

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