Purpose

Iodine 123 labeled meta-iodobenzylguanidine ([¹²³I]MIBG) scan with SPECT/CT imaging is one of the most commonly used imaging modalities in the evaluation of neuroblastoma. [¹⁸F]-meta-fluorobenzylguanidine ([¹⁸F]MFBG) is a novel positron emission tomography (PET) tracer which was reported to have a similar biodistribution to [¹²³I]MIBG. However, the experience of using [¹⁸F]MFBG PET/CT in the evaluation of patients with neuroblastoma is limited. This preliminary investigation aims to assess the efficacy of [¹⁸F]MFBG PET/CT in the evaluation of neuroblastomas in comparison to [¹²³I]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 [¹²³I]MIBG SPECT/CT and [¹⁸F]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 [¹²³I]MIBG and [¹⁸F]MFBG studies. Four of the 34 patients (11.8%) were negative on [¹²³I]MIBG but positive on [¹⁸F]MFBG, while 30 patients were positive on both [¹²³I]MIBG and [¹⁸F]MFBG studies. In these 34 patients, [¹⁸F]MFBG PET/CT identified 784 lesions while [¹²³I]MIBG SPECT/CT detected 532 lesions (p < 0.001). The Curie scores obtained from [¹⁸F]MFBG PET/CT (11.32 ± 8.18, range 1-27) were statistically higher (p < 0.001) than those from [¹²³I]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 [¹⁸F]MFBG study than on the [¹²³I]MIBG imaging.

Conclusion

[¹⁸F]MFBG PET/CT shows higher lesion detection rate than [¹²³I]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