Long-acting somatostatin analog therapy differentially alters 68 Ga-DOTATATE uptake in normal tissues compared with primary tumors and metastatic lesions

Abstract

Synthetic somatostatin analogs have been posed as a potential source of error in somatostatin receptor imaging through interference with tumor detection; however, experimental models and clinical studies have shown a complex mechanism of the effect of octreotide on tumors. The aim of this study was to assess whether 68 Ga-DOTATATE uptake before treatment with long-acting somatostatin analogs differs from that after treatment. Methods: Thirty patients (15 men; age [mean 6 SD], 64.6 6 13.4 y) who had intermediately differentiated to well-differentiated neuroendocrine tumors and who underwent 68 Ga-DOTATATE PET/CT scanning before and after receiving long-acting repeatable octreotide (Sandostati..