Objective: To evaluate the role of (68)Ga-labelled [1, 4, 7, 10-tetraazacyclododecane-1, 4, 7, 10-tetraacetic acid]-1-NaI(3)-Octreotide ((68)Ga-DOTA-NOC) whole body positron emission tomography-computed tomography (PET-CT) as a functional imaging approach for phaeochromocytoma and paraganglioma.
Methods: Thirty-five unrelated patients (Median age-34.4 years; range: 15-71) were evaluated in this prospective study. PET-CT was performed after injection of 132-222 MBq of (68)Ga-DOTA-NOC. Images were evaluated by two experienced nuclear medicine physicians both qualitatively as well as quantitatively (standardised uptake value-SUVmax). In addition we compared the findings with (131)I Metaiodobenzylguanidine (MIBG) scintigraphy, which was available for 25 patients. Histopathology and/or conventional imaging with biochemical markers were taken as the reference standard.
Results: 44 lesions were detected on (68)Ga-DOTA-NOC PET-CT imaging with an additional detection of 12 lesions not previously known, leading to a change in management of 6 patients. Sensitivity, specificity and accuracy were 100%, 85.7%, and 97.1% on a per patient basis and 100%, 85.7% and 98% on per lesion basis, respectively.(131)I MIBG scintigraphy was concordant with (68)Ga-DOTA-NOC PET-CT in 16 patients and false negative in 9 patients.
Conclusion: (68)Ga-DOTA-NOC PET-CT is highly sensitive and specific for the detection of phaeochromoctyomas and paragangliomas. It seems better than (131)I MIBG scintigraphy for this purpose.
Key points: • ( 68 ) Ga-DOTA-NOC PET-CT seems useful in patients with phaeochromocytoma and paraganglioma. • This prospective single centre study showed that it has high diagnostic accuracy. • (68) Ga-DOTA-NOC PET-CT seems superior to (131) I-MIBG in these patients.