The Role of ⁶⁸Ga-DOTATATE PET/CT in the Follow-Up of Patients with Pancreatic Neuroendocrine Tumors: a Retrospective Study

Abstract

Purpose: To study the impact of 68Ga-DOTATATE PET/CT on the treatment tactics of metastatic pancreatic neuroendocrine tumors (pNETs).Material and methods: 208 68Ga-DOTATATE PET/CTs enrolled in 50 patients. Each patient underwent 68Ga-DOTATATE PET/CT two to ten times (median 4.2Դ2.2). At the time of the first study, the diagnosis of pNET was confirmed histologically and immunohistochemically in all patients. CT and MRI, as well as assessment of biochemical recurrence (serotonin and chromogranin-A levels exceeding the reference intervals) performed in all patients within one month before the next PET/CT. The results of all the listed studies in the detection of recurrent metastatic pNETs compared.Results: At the first 68Ga-DOTATATE PET/CT, metastases were detected in 46 patients out of 50 (92 %). At the same time, prior to the first PET/CT, CT and MRI revealed tumor foci only in 34 patients (68 %). Thus, compared with routine imaging methods, additional tumor foci detected in 12 patients (24 %). Among all 208 PET/CT examinations, 166 results were positive (79.8 %). According to the results of all CT and MRI studies, tumor foci diagnosed in 117 cases (56.3 %). Compared to CT and MRI, additional tumor foci detected in 49  studies (23.6  %). Metastases on PET/CT detected in 43 studies, despite the absence of biochemical recurrence. On PET/CT, pNETs recurrence was detected in six patients versus three on CT and MRI. Tumor progression — in 10 patients versus five on CT and MRI.Conclusion: We revealed the influence of 68Ga-DOTATATE PET/CT on the management of patients in the absence of other signs of disease recurrence or progression. 68Ga-DOTATATE PET/CT in combination with CT and MRI contributes to earlier diagnosis of recurrent metastatic pNETs.