123I-MIBG Versus 18F-FDG: Which Is Better, or Which Can Be Eliminated? TO THE EDITOR: The excellent paper by Dr. Sharp and

Abstract

colleagues compared the diagnostic utility of 123I-metaiodoben-zylguanidine (MIBG) with 18F-FDG (1). They found that 18F-FDG is superior to 123I-MIBG in stage 1 and 2 neuroblas-toma and that 123I-MIBG is superior to 18F-FDG in stage 4 neuroblastoma. The authors comment that for socioeconomic and radiation exposure reasons, a reduction in the total number of imaging procedures may be desirable in neuroblastoma patients. In this setting, what is important is not necessarily which test is superior. Rather, we want to know if one of these imaging tests can be safely eliminated. The answer is no. Not in early-stage neuroblastoma, and not in late-stage neuroblastoma. The authors found that in 10 of 10 patients with early disease, 18F-FDG was equivalent or superior to 123I-MIBG. But the 95 % confidence interval for this ranges from about 72 % t