18F-FDOPA PET/CT is particularly helpful for imaging PPGLs in clusters 1B (VHL and PZS) and 2 (MEN-2 and NF-1) and has an advantage over MIBG in that normal adrenal tissue has lower uptake, increasing the sensitivity to detect nonmetastatic PCC (94% in patients of known genetic background and up to 100% in patients with apparently sporadic nonmetastatic PCC); indeed, the detection of metastatic PPGL may also vary on the basis of the genetic background with greater sensitivity in non-SDHx PPGL (42, 73). This evidence concerns the gene NF1 and adrenal gland pheochromocytoma.