Radiochemical purity and patient preparation: Key factors affecting the accuracy of 68Ga-DOTATOC PET/CT imaging in neuroendocrine tumors

Abstract

Gallium-68-DOTA-D-phe1-try3-octreotide (⁶⁸Ga-DOTATOC) positron emission tomography/computed tomography (PET/CT) is a crucial diagnostic tool for neuroendocrine tumors (NET). Its accuracy is influenced by radiochemical purity and patient preparation. We present two cases where unexpected radiotracer uptake in ⁶⁸Ga-DOTATOC PET/CT imaging was observed. One case involved high vascular activity and reduced tumor-to-background contrast, attributed to radiochemical impurities. The other case demonstrated blocked somatostatin receptors due to inadequate patient preparation. Both cases highlight the importance of strict radiolabeling protocols and quality control measures, such as thin-layer chromatography (TLC), to ensure accurate ⁶⁸Ga-DOTATOC PET/CT results. Additionally, proper patient preparation, including discontinuing somatostatin analogues as recommended, is essential for optimizing diagnostic accuracy. By addressing these factors, healthcare providers can improve the effectiveness of ⁶⁸Ga-DOTATOC PET/CT in diagnosing and managing NET.