The Impact of 68Ga-DOTATOC Positron Emission Tomography/Computed Tomography on the Multimodal Management of Patients With Neuroendocrine Tumors

Abstract

To evaluate the impact of 68Ga-DOTATOC positron emission tomography (PET)/computed tomography (CT) on the multimodal management of neuroendocrine tumors (NET). Establishment of the extent and progression of NET are necessary to decide which treatment option to choose. However, morphological imaging with CT or magnetic resonance imaging (MRI) is often inadequate in identifying the primary tumor and/or in detecting small metastatic lesions. In total, 52 patients (27 women and 25 men) with histologically proven NET could be included in the protocol of comparison between 68Ga-DOTATOC PET/CT and CT and/or MRI. The examinations were performed in terms of tumor staging and, in some instances, also of primary tumor site identification to evaluate the patient's eligibility for treatment. Each patient presented with either CT and/or MRI performed elsewhere and consecutively underwent 68Ga-DOTATOC PET/CT in our institution. In all 52 patients, 68Ga-DOTATOC PET/CT demonstrated pathologically increased uptake for at least 1 tumor site, yielding a sensitivity of 100% on a patient basis. In 3 of 4 patients with unknown primary tumor site, 68Ga-DOTATOC PET/CT visualized the primary tumor region (jejunum, ileum, and pancreas, respectively) not identified on CT and/or MRI. 68Ga-DOTATOC PET/CT detected additional hepatic and/or extrahepatic metastases in 22 of the 33 patients diagnosed with hepatic metastases on CT and/or MRI. Of the 15 patients evaluated for liver transplantation, we omitted 7 (46.6%) from further screening because of evidence of metastatic deposits not seen by conventional imaging. Overall, 68Ga-DOTATOC PET/CT altered our treatment decision based on CT and/or MRI alone, in 31 (59.6%) of the 52 patients. In this study, 68Ga-DOTATOC PET/CT proved clearly superior to CT and/or MRI for detection and staging of NET. More important, 68Ga-DOTATOC PET/CT impacted our treatment decision in more than every second patient.