[18F]mFBG PET-CT for detection and localisation of neuroblastoma: a prospective pilot study

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

Automated summary

This pilot study investigates the feasibility of [F-18]mFBG PET-CT for imaging in neuroblastoma. The results demonstrate that [F-18]mFBG PET-CT is superior to [I-123]mIBG scanning in detecting tumor localization and assessing disease status in neuroblastoma patients.