A Double-blind Non Inferiority Clinical Trial to Compare the Nephroprotection of Cilastatn Versus Thiosulfate in Patients Undergoing Debulking Surgery With Intraoperative Hyperthermic Intraperitoneal Chemotherapy With Cisplatin.

• Age: adult patients aged 18-75 years.

Sex: female. Eastern Cooperative Oncology Group Performance Status (ECOG PS) ≤ 2. General condition: patients eligible for major surgery, with creatinine, bilirubin, and blood count values within or close to the normal range (Hb >10 g/dL, leukocytes >3,000/mL, neutrophils >1,000/mL, platelets >100,000/mL).

Patients evaluated by the Anesthesiology Department and deemed fit for surgery. Signed informed consent. Disease confined to the abdomen: CRS + HIPEC is not indicated in patients with pulmonary, bone, or other distant metastases. Patients with limited hematogenous metastases to the spleen or liver may be considered. Patients with regional or distant intra-abdominal lymphatic dissemination may also be considered, provided complete resection is feasible. FIGO stage IVA epithelial ovarian carcinoma at presentation, due to pleural effusion with mediastinal lymph node or splenic metastases, is an indication for neoadjuvant chemotherapy; if response is achieved, CRS + HIPEC may subsequently be considered.

Multidisciplinary Committee evaluation: radiological PCI is assessed, and the likelihood of achieving complete cytoreduction is estimated to determine the indication for CRS + HIPEC.

Exclusion Criteria:

• Lack of consent to participate in the clinical trial. Eastern Cooperative Oncology Group Performance Status (ECOG PS) > 2. Not eligible for major surgery. Disease not confined to the abdomen, or with findings indicating that optimal cytoreduction is not achievable (e.g., intestinal obstruction, biliary obstruction, ureteral obstruction, or diffuse involvement of the small bowel or mesentery).

Known hypersensitivity to platinum-based agents.