Clinical application of 18 F-FDOPA PET/CT imaging in the diagnosis of pheochromocytoma/para-ganglioma / 中华核医学与分子影像杂志

ABSTRACT

Objective To explore the efficiency of 6-18 F-fluoro-L-3,4-dihydroxyphenylalanine (18 F-FDOPA) PET/CT imaging in the diagnosis of pheochromocytoma/paraganglioma (PPGLs). Methods Twenty-six patients (15 males, 11 females;age13-76 years) who were suspected of PPGLs with adrenal or retro-peritoneal mass were enrolled into this prospective study. All patients underwent 18 F-FDOPA PET/CT ima-ging. The clinical data, laboratory data and imaging results were collected. Region of interest ( ROI) was drawn on the liver and lesions, and the mean standardized uptake value ( SUVmean ) of the liver and the max-imum standardized uptake value ( SUVmax ) of lesions were calculated, as well as the ratio of tumor/lesion ratio ( T/L) . Based on the pathological results considered as the gold standard, the diagnostic efficiency of 18 F-FDOPA PET/CT imaging in PPGLs was calculated and compared with that of CT/MR. Besides, receiv-er operating characteristic ( ROC) curve analysis of T/L was used. Results Twenty-five patients were path-ologically confirmed, including 12 patients with PPGLs and 13 patients with non-PPGLs. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of 18 F-FDOPA PET/CT ima-ging was 11/12, 12/13, 92.00％(23/25), 11/12 and 12/13, respectively. The area under the ROC curve of T/L was 0.978, with the cut-off value of 1.55. 18 F-FDOPA PET/CT imaging totally detected 29 positive foci, including 12 of pheochromocytoma (PCC) and 17 of paraganglioma (PGL). Among those 18F-FDOPA positive PGL foci, 11 were detected by CT/MR, while 6 with diameter less than 1 cm were missed. Conclu-sion 18 F-FDOPA PET/CT imaging can detect more small PGL lesions than CT/MR, suggesting that it may be a proper imaging modality of PPGLs.