[18F]Fluoro-PEG-folate PET/CT Imaging in Epithelial Ovarian Cancer

Inclusion Criteria: Patients with radiologically FIGO stage IIIB/IIIC EOC based on the conventional CT scan who are: * scheduled to undergo primary cytoreductive surgery and 1. in whom EOC is histologically proven, or 2. in whom EOC is cytologically suspected and a serum CA125/CEA ratio \> 25 is found or * treated with neoadjuvant chemotherapy (NACT) and are scheduled to undergo interval cytoreductive surgery and 1. in whom EOC is histologically proven, or 2. in whom EOC is cytologically suspected and a serum CA125/CEA ratio \> 25 was found before NACT 3. and with radiologically FIGO stage IIIB/IIIC EOC based on the response evaluation CT scan after NACT Exclusion Criteria: 1. Women younger than 30 years of age (in accordance with the guidelines of the Netherlands Commission on Radiation Dosimetry \[23\], as the total radiation dose will be 7.2 mSv) 2. Patients who previously underwent primary laparotomy and in whom complete or optimal cytoreduction was not considered feasible. 3. Contraindication for PET (pregnancy, lactating or severe claustrophobia) 4. Thrombocytopenia (platelet count \< 100 x 10\^9/L) and/or INR \> 2 5. Impaired renal function (defined as eGFR \< 50 mL/1.73 m2) 6. Impaired liver function (ALT, AST or total bilirubin \> 3x upper limit of normal) 7. Clinically significant abnormalities on ECG and/or clinically laboratory test 8. Inability to tolerate lying supine for the duration of a PET/CT examination (\~110 minutes) 9. Patients with concomitant malignancy (except basal cell carcinoma of the skin) or any condition that in the opinion of the investigators could potentially jeopardize the health status of the patient 10. Patients not able to comply with the study procedures 11. Patients who did not give informed consent