[123I]-mIBG and [18F]-FDOPA differential uptake in the follow-up of neonatal neuroblastoma

EJNMMI Rep. 2025 Oct 6;9(1):34. doi: 10.1186/s41824-025-00269-1.

ABSTRACT

Single photon emission computed tomography (SPECT/CT) using meta-iodobenzylguanidine (mIBG) is currently recommended in pediatric clinical guidelines for assessing neuroblastoma. However, [¹²³I]-mIBG scintigraphy may sometimes be less sensitive than positron emission tomography/computed tomography (PET/CT) using [¹⁸F]-FDOPA. In order to enhance diagnostic reliability and minimize the risk of missing lesions, both nuclear medicine imaging modalities were used here. We present a case study of a newborn girl who was diagnosed with neuroblastoma in utero. [¹⁸F]-FDOPA PET/CT scans showed faint uptake related to the lesion, whereas [¹²³I]-mIBG scintigraphy was more sensitive and correlated with an MRI-suspicious mass. The metabolic pathways explored by the two tracers are different and sometimes complementary. [¹²³I]-mIBG has an affinity for the norepinephrine transporter, whereas [¹⁸F]-FDOPA has an affinity for the large neutral amino acid transporter-1. The role of [¹⁸F]-FDOPA PET/CT in neuroblastoma is evolving and has been demonstrated to have high sensitivity, but surprisingly, in this particular case, it has limited specificity for neuroblastoma, which was taken into account when interpreting the [¹⁸F]-FDOPA PET/CT scan.

PMID:41047453 | DOI:10.1186/s41824-025-00269-1