68Ga-DOTATATE PET/CT in Neuroendocrine Tumor

Study Overview
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Brief Summary
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Somatostatin receptor(SSTR) was expressed in neuroendocrine tumor cells and SSTR-targeting molecular imaging(68Ga-DOTATATE PET/CT) could be a promising technique to evaluate the primary tumor and metastatic lesions of neuroendocrine tumors with higher accuracy. This prospective study is going to investigate whether radiolabeled somatostatin analogs 68Ga-DOTATATE PET/CT may be valuable for diagnosis, risk stratification, and prognostic evaluation of neuroendocrine tumors and compared it with 18F-FDG PET/CT.

Detailed Description
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Neuroendocrine tumor(NET)can be derived from endocrine glands, endocrine tissues and endocrine cells from any parts of body. Due to its occult onset and heterogeneity, it is hard to be detected by conventional imaging like CT and it is often at late stage when diagnosed. New imaging modality such as 18F-FDG PET/CT have been well-accepted as a practical way to evaluate the aggressive of tumor. 18F-FDG PET/CT has been used to improve the efficacy in assessing the extent and severity of NET, but the diagnostic accuracy of 18F-FDG PET/CT decreased in low proliferation tumor cells and inflammation. Recent studies showed somatostatin receptor (SSTR) was expressed in NET cells and SSTR-targeting molecular imaging-68Ga-DOTATATE PET/CT could be a promising technique to evaluate the extent of NET with higher accuracy. Especially in some well differentiated tumor, 18F-FDG PET/CT can be negative, while 68Ga-DOTATATE PET/CT can be positive. However, the results can be varied in these two imaging modalities and characterized this disease at multiple levels such as clinical presentation, biologic characteristics, treatment response, and clinical outcome.This prospective study is going to investigate whether 68Ga-DOTATATE PET/CT may be superior to 18F-FDG PET/CT for diagnosis, risk stratification, and prognostic evaluation of NET.

Official Title
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68Ga-DOTATATE PET/CT for Detection and Evaluation of Neuroendocrine Tumor

Conditions
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Neuroendocrine Tumors

Intervention / Treatment
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* Drug: 68Ga-DOTATATE


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: suspected or confirmed untreated NET patients previously performed 18F-FDG PET/CT signed written consent. Exclusion Criteria: pregnancy breastfeeding known allergy against TATE any medical condition that in the opinion of the investigator, may significantly interfere with study compliance.

Ages Eligible for Study
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Minimum Age: 7 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 68Ga-DOTATATE PET/CT<br>Inject 68Ga-DOTATATE and then perform PET/CT scan | Drug: 68Ga-DOTATATE<br>* Intravenous injection of one dosage of 74-148 MBq (2-4 mCi) 68Ga-DOTATATE. Tracer doses of 68Ga-DOTATATE will be used to image lesions of NET PET/CT scan.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| SUVmax | SUVmax of focal lesions are measured on 68Ga-DOTATATE PET/CT. The SUVmax higher than that of the normal liver tissue is defined as positive. | through study completion, an average of 3 years | 
| Diagnostic value | Diagnostic value of 68Ga-DOTATE PET/CT for NET in comparison with 18F-FDG PET/CT | through study completion, an average of 3 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Diagnostic value in different grades/types of NET | Diagnostic value of 68Ga-DOTATATE PET/CT in ectopic ACTH-secreting tumor, insulinoma, glucagonoma and so on. | through study completion, an average of 3 years | 
| Overall Survival(OS) | Analysis of OS for patients receiving 68Ga-DOTATATE PET/CT | 1 year and 5 years after been diagnosed | 
| Progressive free survival(PFS) | Analysis of PFS for patients receiving 68Ga-DOTATATE PET/CT | 1 year and 5 years after been diagnosed | 
| SSTR expression/Ki67 and SUV | Correlation between SSTR expression/Ki 67 and SUV in PET | through study completion, an average of 3 years | 
| Risk stratification | Analysis of risk factors and OS/PFS | through study completion, an average of 3 years |