Superiority of [⁶⁸Ga]-DOTATATE PET/CT to other functional imaging modalities in the localization of SDHB-associated metastatic pheochromocytoma and paraganglioma

Objectives Patients with SDHB mutation-related pheochromocytoma/paraganglioma (PHEO/PGL) are at a high risk for metastases and show worse outcomes compared to other hereditary PHEOs/PGLs. Current therapeutic approaches are limited but the best outcomes are based on the detection of as many lesions as possible. The main goal of our study was to evaluate the diagnostic utility of [⁶⁸Ga]-DOTATATE PET/CT in comparison to [¹⁸F]-fluoro-2-deoxy-D-glucose ([¹⁸F]-FDG), [¹⁸F]-L-dihydroxyphenylalanine ([¹⁸F]-FDOPA), [¹⁸F]-fluorodopamine ([¹⁸F]-FDA) PET/CT, and in comparison to CT/MRI.

Methods [⁶⁸Ga]-DOTATATE PET/CT was prospectively performed in 17 patients with SDHB-related metastatic PHEOs/PGLs. All patients also underwent [¹⁸F]-FDG PET/CT and CT/MRI with 16 of the 17 patients receiving [¹⁸F]-DOPA and [¹⁸F]-FDA PET/CT. Detection rates of metastatic lesions were compared between all these functional imaging studies. A composite of all used functional and anatomical imaging studies was used as imaging comparator.

Results [⁶⁸Ga]-DOTATATE PET/CT demonstrated a lesion-based detection rate of 98.6%. [¹⁸F]-FDG, [¹⁸F]-FDOPA, [¹⁸F]-FDA PET/CT, and CT/MRI showed detection rates of 85.5% (p<0.01), 61.4%, (p<0.01), 51.9% (p<0.01), and 84.8% (p<0.01), respectively.

Conclusions [⁶⁸Ga]-DOTATATE PET/CT showed a significantly superior detection rate compared to all other functional and anatomical imaging modalities and may replace the currently recommended [¹⁸F]-FDG PET/CT as the preferred functional imaging modality in the evaluation of SDHB-related metastatic PHEO/PGL.