[ 18 F]MFBG PET/CT outperforming [ 123 I]MIBG SPECT/CT in the evaluation of neuroblastoma

Purpose Iodine 123 labeled meta-iodobenzylguanidine ([ 123 I]MIBG) scan with SPECT/CT imaging is one of the most commonly used imaging modalities in the evaluation of neuroblastoma. [ 18 F]-meta-fluorobenzylguanidine ([ 18 F]MFBG) is a novel positron emission tomography (PET) tracer which was reported to have a similar biodistribution to [ 123 I]MIBG. However, the experience of using [ 18 F]MFBG PET/CT in the evaluation of patients with neuroblastoma is limited. This preliminary investigation aims to assess the efficacy of [ 18 F]MFBG PET/CT in the evaluation of neuroblastomas in comparison to [ 123 I]MIBG scans with SPECT/CT. Materials and methods In this prospective, single-center study, 40 participants (mean age 6.0 ± 3.7 years) with history of neuroblastoma were enrolled. All children underwent both [ 123 I]MIBG SPECT/CT and [ 18 F]MFBG PET/CT studies. The number of lesions and the Curie scores revealed by each imaging method were recorded. Results Six patients had negative findings on both [ 123 I]MIBG and [ 18 F]MFBG studies. Four of the 34 patients (11.8%) were negative on [ 123 I]MIBG but positive on [ 18 F]MFBG, while 30 patients were positive on both [ 123 I]MIBG and [ 18 F]MFBG studies. In these 34 patients, [ 18 F]MFBG PET/CT identified 784 lesions while [ 123 I]MIBG SPECT/CT detected 532 lesions ( p < 0.001). The Curie scores obtained from [ 18 F]MFBG PET/CT (11.32 ± 8.18, range 1-27) were statistically higher ( p < 0.001) than those from [ 123 I]MIBG SPECT/CT (7.74 ± 7.52, range 0-26). 30 of 34 patients (88.2%) with active disease on imaging had higher Curie scores based on the [ 18 F]MFBG study than on the [ 123 I]MIBG imaging. Conclusion [ 18 F]MFBG PET/CT shows higher lesion detection rate than [ 123 I]MIBG SPECT/CT in the evaluation of pediatric patients with neuroblastoma. Clinical trial registration Clinicaltrials.gov : NCT05069220 (Registered: 25 September 2021, retrospectively registered); Institute Review Board of Peking Union Medical College Hospital: ZS-2514