Department of General and Visceral Surgery, Zentralklinik Bad Berka GmbH, Robert-Koch-Allee 9, 99437 Bad Berka, Germany.
Eur J Nucl Med Mol Imaging. 2011 Sep;38(9):1659-68. doi: 10.1007/s00259-011-1846-5. Epub 2011 May 31.
Somatostatin receptors (SSTR) are known for an overexpression in gastroenteropancreatic neuroendocrine tumours (GEP-NET). The aim of the present study was to find out if the receptor density predicted by the semi-quantitative parameters generated from the static positron emission tomography (PET/CT) correlated with the in vitro immunohistochemistry using a novel rabbit monoclonal anti-SSTR2A antibody (clone UMB-1) for specific SSTR2A immunohistochemistry and polyclonal antibodies for SSTR1 and 3-5.
Overall 14 surgical specimens generated from 34 histologically documented GEP-NET patients were correlated with the preoperative (68)Ga-DOTA-NOC PET/CT. Quantitative assessment of the receptor density was done using the immunoreactive score (IRS) of Remmele and Stegner; the additional 4-point IRS classification for immunohistochemistry and standardized uptake values (SUV(max) and SUV(mean)) were used for PET/CT.
The IRS for SSTR2A and SSTR5 correlated highly significant with the SUV(max) on the PET/CT (p < 0.001; p < 0.05) and the IRS for SSTR2A with the SUV(mean) (p < 0.013). The level of SSTR2A score correlated significantly with chromogranin A staining and indirectly to the tumour grading.
The highly significant correlation between SSTR2A and SSTR5 and the SUV(max) on the (68)Ga-DOTA-NOC PET/CT scans is concordant with the affinity profile of (68)Ga-DOTA-NOC to the SSTR subtypes and demonstrates the excellent qualification of somatostatin analogues in the diagnostics of NET. This study correlating somatostatin receptor imaging using (68)Ga-DOTA-NOC PET/CT with immunohistochemically analysed SSTR also underlines the approval of therapy using somatostatin analogues, follow-up imaging as well as radionuclide therapy.
生长抑素受体 (SSTR) 在胃肠胰神经内分泌肿瘤 (GEP-NET) 中过度表达。本研究旨在探讨静态正电子发射断层扫描 (PET/CT) 生成的半定量参数预测的受体密度是否与使用新型兔单克隆抗 SSTR2A 抗体 (克隆 UMB-1) 进行特异性 SSTR2A 免疫组织化学和多克隆抗体进行的体外免疫组织化学相关SSTR1 和 3-5。
对 34 例经组织学证实的 GEP-NET 患者的 14 例手术标本进行了术前（68）Ga-DOTA-NOC PET/CT 相关性分析。使用 Remmele 和 Stegner 的免疫反应评分 (IRS) 对受体密度进行定量评估；对免疫组织化学采用额外的 4 分 IRS 分类，对 PET/CT 采用标准化摄取值 (SUV(max) 和 SUV(mean))。
SSTR2A 和 SSTR5 的 IRS 与 PET/CT 的 SUV(max) 高度显著相关 (p < 0.001；p < 0.05)，SSTR2A 的 IRS 与 SUV(mean) 相关 (p < 0.013)。SSTR2A 评分水平与嗜铬粒蛋白 A 染色显著相关，间接与肿瘤分级相关。
SSTR2A 和 SSTR5 与 (68)Ga-DOTA-NOC PET/CT 扫描的 SUV(max) 之间的高度显著相关性与 (68)Ga-DOTA-NOC 对 SSTR 亚型的亲和力谱一致，并证明了生长抑素类似物在 NET 诊断中的优异定性。本研究将使用 (68)Ga-DOTA-NOC PET/CT 进行的生长抑素受体成像与免疫组织化学分析的 SSTR 相关联，也强调了使用生长抑素类似物进行治疗、随访成像和放射性核素治疗的批准。
