Differentiation of suprasellar meningiomas from non-functioning pituitary macroadenomas by 18F-FDG and 13N-Ammonia PET/CT

Lei Ding,Xinchong Shi,Xiangsong Zhang,Zhoulei Li,Qiao He,Fangling Zhang,Ruocheng Li

doi:10.1186/s12885-020-06852-y

Abstract

BackgroundDifferentiation of suprasellar meningiomas (SSMs) from non-functioning pituitary macroadenomas (NFPMAs) is useful for clinical management. We investigated the utility of 13N-ammonia combined with 18F-FDG positron emission tomography (PET)/computed tomography (CT) in distinguishing SSMs from NFPMAs retrospectively.MethodsFourteen NFPMA patients and eleven SSM patients with histopathologic diagnosis were included in this study. Every patient underwent both 18F-FDG and 13N-ammonia PET/CT scans. The tumor to gray matter (T/G) ratios were calculated for the evaluation of tumor uptake.ResultsThe uptake of 18F-FDG was higher in NFPMAs than SSMs, whereas the uptake of 13N-ammonia was obviously lower in NFPMAs than SSMs. The differences of 18F-FDG and 13N-ammonia uptake between the two groups were significant respectively (0.92[0.46] vs 0.59[0.29], P < 0.05, 18F-FDG; 1.58 ± 0.56 vs 2.80 ± 1.45, P < 0.05, 13N-ammonia). Tumor classification demonstrated a high overall accuracy of 96.0% for differential diagnosis. When the two traces were combined, only 1 SSM was misclassified into the NFPMA group.ConclusionSSMs and NFPMAs have different metabolic characteristics on 18F-FDG and 13N-ammonia PET images. The combination of these two tracers can effectively distinguish SSMs from NFPMAs.

Highlights

Differentiation of suprasellar meningiomas (SSMs) from non-functioning pituitary macroadenomas (NFPMAs) is useful for clinical management
Magnetic resonance imaging (MRI) should be complemented by positron emission tomography (PET) in whether diagnosis and staging before treatment or postoperative therapeutic effectiveness monitoring [9] .13N-ammonia is suggested to be a contrast-enhanced radiotracer which is more sensitive and specific than Gadolinium-Diethylenetriaminepentaacetic acid (GdDTPA) [10]
We have reported the clinical usefulness of 13N-ammonia in many brain tumors through a series of studies [11,12,13,14]

Summary

Introduction

Differentiation of suprasellar meningiomas (SSMs) from non-functioning pituitary macroadenomas (NFPMAs) is useful for clinical management. We investigated the utility of 13N-ammonia combined with 18F-FDG positron emission tomography (PET)/computed tomography (CT) in distinguishing SSMs from NFPMAs retrospectively. Accurate preoperative diagnosis is still quite challenging and difficult by current morphological imaging modalities alone because of the overlap of imaging findings and the relatively rarity of SSMs. MRI should be complemented by PET in whether diagnosis and staging before treatment or postoperative therapeutic effectiveness monitoring [9] .13N-ammonia is suggested to be a contrast-enhanced radiotracer which is more sensitive and specific than Gadolinium-Diethylenetriaminepentaacetic acid (GdDTPA) [10]. We have reported the clinical usefulness of 13N-ammonia in many brain tumors through a series of studies [11,12,13,14]. We aimed to investigate the combined efficiency of 18F-FDG and 13N-ammonia PET/CT in distinguishing SSMs from NFPMAs

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