P03.03.B PREVALENCE AND SIGNIFICANCE OF INCIDENTAL PET FINDINGS IN THE BRAIN USING RADIOTRACERS OTHER THAN [18F]FDG: A META-ANALYSIS

Abstract BACKGROUND Incidental brain imaging findings could be clinically relevant and advancements in molecular imaging could lead to a more frequent identification. The aim of this study is to perform a meta-analysis to establish the prevalence and the clinical significance of brain incidentalomas at PET (BIP) using radiotracers other than [18F]FDG. MATERIAL AND METHODS A comprehensive literature search of studies about BIP was carried out. Four different databases (PubMed/MEDLINE, EMBASE, Cochrane library, Google Scholar) were screened until April 2025. Only original articles about BIP using radiotracers other than [18F]FDG were selected. Three review authors independently performed the literature search, the article selection and the data extraction. A proportion meta-analysis on the prevalence and significance of BIP was carried out on a patient-based analysis using a random-effects model. RESULTS 14 studies (11211 patients) were included in the meta-analysis, 6 using somatostatin receptor (SSTR)-PET, 5 using choline-PET, one using prostate-specific membrane antigen (PSMA)-PET, one using [18F]FDOPA-PET and one using [18F]Fluciclovine-PET. The pooled prevalence of BIP was 4.6% for SSTR-PET, 1.1% for choline-PET, 1.2% for PSMA-PET, 1.4% for [18F]FDOPA-PET and 2.5% for [18F]Fluciclovine-PET. When BIP were further evaluated using MRI, meningiomas were the most frequent lesions detected but both benign and malignant lesions could be incidentally diagnosed. Moderate statistical heterogeneity was found in the meta-analysis. CONCLUSION BIP using radiotracers other than [18F]FDG are not rare, in particular for SSTR-PET, further justifying the extension of PET scans to the brain when radiotracers other than [18F]FDG are used. When detected, a BIP should be further evaluated using brain MRI. Meningioma is the most common lesion causing a BIP but both benign and malignant lesions could be incidentally detected. Further studies are warranted to better clarify the clinical impact of BIP detection.