The new era of bio-molecular imaging with O-(2-18F-fluoroethyl)-L-tyrosine (18F-FET) in neurosurgery of gliomas

Purpose The possibility to provide answers from morphological imaging to neurosurgeon needs in patients with high- and low-grade gliomas relies on FLAIR images and percentage increase of contrast enhancement on T1-weighted images. Molecular imaging investigating the functionality of tumor cells has been progressively introduced in surgery planning to overcome limitations of conventional MRI. The purpose is to highlight the potential diagnostic and prognostic role of 18F-FET PET in gliomas. Methods We performed a literature review for articles on the topic in PubMed, Google Scholar, and Web of Science until January 2022. Search keywords included "glioma", "glioblastoma", "tumor biology" "18F-FET", "MRI", "surgery". Results This review provides evidence of the potential of molecular imaging with 18F-FET to address the surgeon diagnostic and prognostic needs, including the knowledge of precise burden of cancer to guide biopsy or maximal safe resection, tumor grade and residual disease. The main cornerstones underlying the capacity of molecular imaging to provide information concerning tumor biology are deeply discussed to make the reader confident with the role of 18F-FET as a reliable imaging bio-marker in gliomas. Conclusion Although conventional MRI has been shown to be reliable technique to identify gliomas in terms of morphological concerns, some important limitations depending on the incapacity to reveal the tumor biology have emerged. The 18F-FET PET has been established to provide early information of functional nature including real tumor extension, grade, and metabolic residual disease. Therefore, the use of 18F-FET PET has progressively increased suggesting a potential shift from a morphological to functional plus morphological neurosurgery.