The goal of this clinical trial is to learn whether repeated cisplatin-based PIPAC added to standard TC chemotherapy can improve outcomes in women aged 18-75 years with newly diagnosed FIGO IIIB-IIIC epithelial ovarian cancer and visually detectable peritoneal carcinomatosis. The main questions are whether repeated PIPAC increases the rate of complete surgical cytoreduction (CRS R0) and whether it improves disease control, survival outcomes, and safety compared with standard combined treatment including a single PIPAC procedure. Participants will undergo screening, intraoperative randomization, systemic chemotherapy, PIPAC procedures according to study arm, interval cytoreductive surgery, protocol-specified postoperative treatment if needed, and regular follow-up assessments.