Abstract
OBJECTIVE: In epithelial ovarian cancer (EOC), 2-fluorine-18-fluoro-deoxy-glucose (2-[18F]-FDG)-positron emission tomography (PET) with computed tomography (CT) outperforms CT and magnetic resonance imaging (MRI) in metastasis detection. The aim of this early interim study was to assess feasibility of the study workflow to evaluate accuracy of 2[18F]-FDG-PET/CT and 2[18F]-FDG-PET/MRI compared to stand-alone modalities in primary EOC staging. METHODS: The first seven consecutive EOC participants in the prospective PRODIGYN study (NCT05855941) were included. All underwent 2[18F]-FDG-PET/CT and 2[18F]-FDG-PET/MRI at baseline and 6/7 at 3-month evaluation. Molecular imaging-based stage according to International Federation of Gynaecology and Obstetrics (miFIGO) with 2[18F]-FDG-PET/CT and 2[18F]-FDG-PET/MRI was compared to conventional radiological FIGO stage (crFIGO) with CT and MRI, using histopathological FIGO (pFIGO) as reference. At 3 months, therapy response assessment was performed with RECIST 1.1 and PERCIST. RESULTS: At baseline, lymph node metastases were found in 3/7 with both modalities, and distant metastases in 2/7 with 2[18F]-FDG-PET/CT and 1/7 with PET/MRI. miFIGO was higher than crFIGO in 2/7, lower in 2/7, and the same in 3/7. At the 3-month therapy response assessment, RECIST 1.1 showed complete response in all, and PERCIST in 5/6, with partial response in 1/6. CONCLUSION: The PRODIGYN study workflow appears feasible for accuracy assessment of 2[18F]-FDG-PET/CT and 2[18F]-FDG-PET/MRI compared to stand-alone modalities in primary EOC staging. Early data indicate a possible added value of 2[18F]-FDG-PET/CT and 2[18F]-PET/MRI.