FDG PET in the evaluation of phaeochromocytoma: a correlative study with MIBG scintigraphy and Ki-67 proliferative index

To compare 123I-metaiodobenzylguanidine (MIBG) and [Fluorine-18]-2-fluoro-2-deoxy-d-glucose (FDG) positron emission tomography (PET) in 22 patients with phaeochromocytomas and paragangliomas (PGL) retrospectively and to evaluate the correlation between FDG uptake and Ki-67 proliferative index. Fourteen of 17 (82%) patients at initial diagnosis had positive FDG uptake, more intensely in PGL. Eleven of 12 (92%) patients had positive MIBG uptake. PET and MIBG scintigraphy were concordant in 10 patients, discordant in 6. Combined results yielded no false negative findings and are complementary. Neither maximum standardised uptake value nor visual scores on MIBG correlated with Ki-67.