MIBG Curie and SIOPEN scores

What is measured: the extent of MIBG-avid disease on a whole-body scan. How: iodine-123 MIBG planar and SPECT imaging (with a bone scan or FDG PET for the roughly 10 percent of tumours that do not take up MIBG); the Curie score grades nine skeletal segments and one soft-tissue site from 0 to 3 (maximum 30) and the SIOPEN score grades twelve skeletal segments from 0 to 6 (maximum 72). What a result changes: at diagnosis it stages metastatic disease and establishes MIBG avidity for later iodine-131 MIBG therapy; after induction, a Curie score above 2 (COG A3973) or a SIOPEN score above 3 predicts worse event-free survival in high-risk disease and is used to stratify and to select patients for intensified or experimental arms, such as adding iodine-131 MIBG in COG ANBL1531; the International Neuroblastoma Response Criteria of 2017 use MIBG to score skeletal response. Fluorine-18 MFBG PET, a same-day tracer with higher resolution, is replacing MIBG in trials. Where it matters: neuroblastoma and high-risk neuroblastoma.