18FmFBG PET-CT for detection and localisation of neuroblastoma: a prospective pilot study

Abstract Purpose Meta - 18 Ffluorobenzylguanidine ( 18 FmFBG) is a positron emission tomography (PET) radiotracer that allows for fast and high-resolution imaging of tumours expressing the norepinephrine transporter. This pilot study investigates the feasibility of 18 FmFBG PET-CT for imaging in neuroblastoma. Methods In a prospective, single-centre study, we recruited children with neuroblastoma, referred for meta - 123 Iiodobenzylguanidine ( 123 ImIBG) scanning, consisting of total body planar scintigraphy in combination with single-photon emission computed tomography-CT (SPECT-CT). Within two weeks of 123 ImIBG scanning, total body PET-CTs were performed at 1 h and 2 h after injection of 18 FmFBG (2 MBq/kg). Detected tumour localisations on scan pairs were compared. Soft tissue disease was quantified by number of lesions and skeletal disease by SIOPEN score. Results Twenty paired 123 ImIBG and 18 FmFBG scans were performed in 14 patients (median age 4.9 years, n = 13 stage 4 disease and n = 1 stage 4S). 18 FmFBG injection was well tolerated and no related adverse events occurred in any of the patients. Mean scan time for 18 FmFBG PET-CT (9.0 min, SD 1.9) was significantly shorter than for 123 ImIBG scanning (84.5 min, SD 10.5), p < 0.01. Most tumour localisations were detected on the 1 h versus 2 h post-injection 18 FmFBG PET-CT. Compared to 123 ImIBG scanning, 18 FmFBG PET-CT detected a higher, equal, and lower number of soft tissue lesions in 40%, 55%, and 5% of scan pairs, respectively, and a higher, equal, and lower SIOPEN score in 55%, 30%, and 15% of scan pairs, respectively. On average, two more soft tissue lesions and a 6-point higher SIOPEN score were detected per patient on 18 FmFBG PET-CT compared to 123 ImIBG scanning. Conclusion Results of this study demonstrate feasibility of 18 FmFBG PET-CT for neuroblastoma imaging. More neuroblastoma localisations were detected on 18 FmFBG PET-CT compared to 123 ImIBG scanning. 18 FmFBG PET-CT shows promise for future staging and response assessment in neuroblastoma. Trial registration Dutch Trial Register NL8152.