Diagnostic Performance of 68Ga-DOTATATE PET/CT, 18F-FDG PET/CT and 131I-MIBG Scintigraphy in Mapping Metastatic Pheochromocytoma and Paraganglioma

Purpose To evaluate the diagnostic performance of 6(8)GaDOTATATE F-18-fluorodeoxyglucose (F-18-FDG) positron emission tomography (PET)/computed tomography (CT), F-18-FDGPET/CTand I-131-MIBG scintigraphy in themapping of metastatic pheochromocytoma and paraganglioma. Materials and Methods Seventeen patients (male= 8, female= 9; age range, 13-68 years) with clinically proven or suspicious metastatic pheochromocytoma or paraganglioma were included in this prospective study. Twelve patients underwent all three modalities, whereas five patients underwent Ga-68-DOTATATE and I-131-MIBG without (18)FFDG. A composite reference standard derived from anatomical and functional imaging findings, along with histopathological information, was used to validate the findings. Results were analysed on a per-patient and on per-lesion basis. Sensitivity and accuracy were assessed using McNemar's test. Results On a per-patient basis, 14/17 patients were detected in Ga-68-DOTATATE, 7/17 patients in I-131-MIBG, and 10/12 patients in 18F-FDG. The sensitivity and accuracy of (68)GaDOTATATE, I-131-MIBG and F-18-FDG were (93.3 %, 94.1 %), (46.7 %, 52.9 %) and (90.9 %, 91.7 %) respectively. On a per-lesion basis, an overall of 472 positive lesions were detected; of which 432/472 were identified by Ga-68-DOTATA TE, 74/472 by 131I-MIBG, and 154/300 (patient, n= 12) by 18F-FDG. The sensitivity and accuracy of Ga-68-DOTATATE, 131I-MIBG and 18F-FDG were (91.5 %, 92.6 % p< 0.0001), (15.7 %, 26.0 % p< 0.0001) and (51.3 %, 57.8 % p< 0.0001) respectively. Discordant lesions were demonstrated on 68GaDOTATATE, 131I-MIBG and 18F-FDG. Conclusions Ga-DOTATATE PET/CT shows high diagnostic accuracy than I-131-MIBG scintigraphy and F-18-FDG PET/CT in mapping metastatic pheochromocytoma and paraganglioma.