Molecular imaging of gastroenteropancreatic neuroendocrine tumours with Ga-68 DOTANOC PET/CT and correlation with an immunhistochemical quantification of somatostatin receptors using novel monoclonal and polyclonal antibodies

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Introduction: Receptor PET/CT with somatostatin analogues marked with Gallium-68 (SMS-R-PET/CT) is currently the golden standard in diagnosing gastroenteropancreatic neuroendocrine tumors (GEP-NET), which are known for an overexpression of somatostatin receptors (SSTRs).

Aim(s): This study aims to answer the question as to whether there is a correlation between the SSTR density-data on tumors / metastases, measured with SMS-R-PET/CT based on standard uptake values (SUV), and the staining intensity of the five SSTR subtypes, which were immunhistochemically identified on tumor tissues removed by surgeryThe aim of the study was the correlation of histologically diagnosed GEP-NETs and its immunohistochemically SSTR-status 1-5 to the pre-operative Ga-68 DOTA-NOC PET/CT.

Materials and methods: In 34 patients who were histologically diagnosed with GEP-NET, 44 different tumor tissues were immunohistochemically analyzed for SSTR1-5 and quantitatively evaluated according to HER2-Score and Remmele’s Score of Immunreactivity (IRS). In 26 cases, exact matches of tumor localization on preoperative PET/CT studies with Ga-68 DOTANOC and Ga-68 DOTATATE, respectively, and tumor tissues were found. Considering the partial volume effect of lesions smaller than 15mm, SUVmax and SUVmean were calculated in PET/CT (n=15 localizations). Furthermore, MTD (molecular tumor diameter) and MTV (molecular tumor volume) were measured.

Conference: 7th Annual ENETSConcerence (2010)

Presenting Author: Götze L

Authors: Kaemmerer D, Götze L, Amelie L, Schulz S, Sänger J,

Keywords: molecular imaging, somatostatin receptors SSTR, neuroendocrine tumor, monoclonal and polyclonal antibodies, UMB-1,