AUTHOR=Zhang Bing , He Qiao , Long Yali , Zhang Yuying , Wang Xiaoyan , Chen Zhifeng , Liu Jianbo , Zhang Xiangsong 

TITLE=Comparison of diagnostic efficacy of 18F-FDG PET/CT and 68Ga-DOTANOC PET/CT in ectopic adrenocorticotropic hormone syndrome

JOURNAL=Frontiers in Endocrinology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2022.962800

DOI=10.3389/fendo.2022.962800

ISSN=1664-2392

ABSTRACT=<sec><title>Purpose</title><p>Fluorine-18 (<sup>18</sup>F)-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) and gallium-68 (<sup>68</sup>Ga)-somatostatin analog (SSA) PET/CT imaging have been increasingly used in ectopic adrenocorticotropic hormone syndrome (EAS); however, the diagnostic efficacies of these two methods in patients with EAS remain unclear. Our study aimed to compare the diagnostic efficacies of <sup>18</sup>F-FDG PET/CT and <sup>68</sup>Ga-DOTANOC PET/CT in EAS.</p></sec><sec><title>Methods</title><p>The clinical and imaging data of 68 patients with EAS who underwent <sup>18</sup>F-FDG PET/CT and <sup>68</sup>Ga-DOTANOC PET/CT examinations from December 2016 to April 2021 were analyzed retrospectively, and the diagnostic efficacies of these methods were compared.</p></sec><sec><title>Results</title><p>In 37 cases, imaging was performed to locate the primary tumor lesion (localization group), and in 31 to evaluate tumor load or metastasis (staging group). Primary tumors were detected in 48.65% (18/37) of the localization group patients. According to scan-based analysis, the tumor lesion detection rates and false positive rates of <sup>18</sup>F-FDG PET/CT imaging and <sup>68</sup>Ga-DOTANOC PET/CT imaging were 18.92% vs. 45.95% (<italic>p</italic> &lt; 0.05) and 21.62% vs. 2.70% (<italic>p</italic> &lt; 0.05) respectively. For lesion-based analysis, the tumor lesion detection rates and false positive rates were 24.13% vs. 58.62% (<italic>p &gt;</italic>0.05) and 31.04% vs. 3.45% (<italic>p</italic> &lt; 0.05). In 90.32% (28/31) of the staging group patients, 286 of 292 lesions were confirmed as tumor lesions. Based on scan analysis, the detection rates and false positive rates of <sup>18</sup>F-FDG PET/CT imaging and <sup>68</sup>Ga-DOTANOC PET/CT imaging were 83.87% vs. 67.74% (<italic>p</italic> &gt; 0.05) and 12.90% vs. 9.68% (<italic>p</italic> &gt; 0.05) respectively. Based on lesion analysis, the detection rate and false positive rates were 93.84% vs. 54.80% (<italic>p</italic> &lt; 0.05) and 1.37% vs. 1.03%(<italic>p</italic> &gt; 0.05).</p></sec><sec><title>Conclusion</title><p><sup>68</sup>Ga-DOTANOC PET/CT imaging may be more suitable than <sup>18</sup>F-FDG PET/CT for identifying the primary tumor in patients with EAS, while <sup>18</sup>F-FDG PET/CT may be more advantageous than <sup>68</sup>Ga-DOTANOC PET/CT for patients with suspected metastasis.</p></sec>