Superiority of 68Ga-DOTATATE over 18F-FDG and anatomic imaging in the detection of succinate dehydrogenase mutation (SDHx)-related pheochromocytoma and paraganglioma in the pediatric population

Purpose To evaluate and compare diagnostic performance of Ga-68-DOTA(0)-Tyr(3)-octreotate (Ga-68-DOTATATE) with F-18-fluoro-2-deoxy-D-glucose (F-18-FDG) positron emission tomography-computed tomography (PET/CT) and anatomic imaging using computed tomography and/or magnetic resonance (CT/MR) imaging in detection of SDHx-related pheochromocytomas and paragangliomas (PPGLs) in pediatric patients. Methods Nine pediatric patients (5:4, girls:boys; 14.6 +/- 2.0 years) with an SDHx-related mutation (SDHB:SDHA:SDHD, n = 7:1:1) were included in this retrospective study. At the time of initial diagnosis, 7/9 patients had metastatic disease. They underwent CT/MR imaging along with PET/CT using Ga-68-DOTATATE (n = 9), F-18-FDG (n = 8), and positron emission tomography-magnetic resonance imaging (PET/MR) using F-18-FDG (n = 1). In this manuscript, F-18-FDG PET/CT refers to both F-18-FDG PET/CT and F-18-FDG PET/MR. The per-lesion, per-region, and per-patient detection rates were compared and calculated for each of the imaging modalities. A composite of all functional and anatomic imaging studies served as the imaging comparator. Results Eight out of nine patients were positive for PPGLs on the imaging studies that demonstrated 107 lesions in 22 anatomic regions on the imaging comparator. The per-lesion detection rates for Ga-68-DOTATATE PET/CT, F-18-FDG PET/CT, and CT/MR imaging were 93.5% (95%CI, 87.0% to 97.3%); 79.4% (95%CI, 70.5% to 86.6%); and 73.8% (95%CI, 64.5% to 81.9%), respectively. The per-lesion detection rate for Ga-68-DOTATATE PET/CT was significantly higher than that of F-18-FDG PET/CT (p = 0.001) or CT/MR imaging (p < 0.001). In all of the anatomic regions except abdomen, the per-lesion detection rates for Ga-68-DOTATATE PET/CT was found to be equal or superior to F-18-FDG PET/CT, and CT/MR imaging. The per-region detection rate was 100% (95%CI, 84.6% to 100%) for Ga-68-DOTATATE PET/CT and 90.9% (95%CI, 70.8% to 98.9%) for both F-18-FDG PET/CT and CT/MR imaging. The per-patient detection rates for Ga-68-DOTATATE PET/CT, (18)FDG PET/CT, and CT/MR imaging were all 100% (95%CI, 63.1% to 100%). Conclusion Our preliminary study demonstrates the superiority of Ga-68-DOTATATE PET/CT in localization of SDHx-related PPGLs in pediatric population compared to F-18-FDG PET/CT and CT/MR imaging with the exception of abdominal (excluding adrenal and liver) lesions, and suggests that it might be considered as a first-line imaging modality in pediatric patients with SDHx-related PPGLs.