However, 123I-MIBG scintigraphy has shown reduced sensitivity in extra-adrenal, multiple, or hereditary PGLs (52–75%) associated with von Hippel Lindau syndrome as well as SDHB-related PGLs and patients with metastatic disease in whom 123I-MIBG scintigraphy may underestimate the extent of disease. This evidence concerns the gene SDHB and metastatic neoplasm.