Abstract
PURPOSE: Meta-[(18)F]fluorobenzylguanidine ([(18)F]mFBG) 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)F]mFBG PET-CT for imaging in neuroblastoma. METHODS: In a prospective, single-centre study, we recruited children with neuroblastoma, referred for meta-[(123)I]iodobenzylguanidine ([(123)I]mIBG) scanning, consisting of total body planar scintigraphy in combination with single-photon emission computed tomography-CT (SPECT-CT). Within two weeks of [(123)I]mIBG scanning, total body PET-CTs were performed at 1 h and 2 h after injection of [(18)F]mFBG (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)I]mIBG and [(18)F]mFBG scans were performed in 14 patients (median age 4.9 years, n = 13 stage 4 disease and n = 1 stage 4S). [(18)F]mFBG injection was well tolerated and no related adverse events occurred in any of the patients. Mean scan time for [(18)F]mFBG PET-CT (9.0 min, SD 1.9) was significantly shorter than for [(123)I]mIBG 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)F]mFBG PET-CT. Compared to [(123)I]mIBG scanning, [(18)F]mFBG 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)F]mFBG PET-CT compared to [(123)I]mIBG scanning. CONCLUSION: Results of this study demonstrate feasibility of [(18)F]mFBG PET-CT for neuroblastoma imaging. More neuroblastoma localisations were detected on [(18)F]mFBG PET-CT compared to [(123)I]mIBG scanning. [(18)F]mFBG PET-CT shows promise for future staging and response assessment in neuroblastoma. TRIAL REGISTRATION: Dutch Trial Register NL8152.