If a mass was found by CT, then mIBG scintigraphy (for a mass >2 cm) or MRI (for a mass <2 cm), should be performed next, regardless of whether such a lesion was a paraganglioma or a pheochromocytoma.

The first iteration of MIBG was developed in ... 12 years and older with iobenguane scan positive, unresectable, locally advanced or metastatic pheochromocytoma or paraganglioma who require ...