Body Surface Area-Based Vs Concentration-Based Perioperative Intraperitoneal Chemotherapy after Optimal Cytoreductive Surgery in Colorectal Peritoneal Surface Malignancy Treatment: COBOX Trial.

Background and ObjectivesCytoreductive surgery (CRS) and hyperthermic intraperitoneal perioperative chemotherapy (HIPEC) are the standard of care for patients diagnosed with colorectal peritoneal surface malignancy (PSM). Despite a clearly defined standardization of CRS, a large variety of HIPEC modalities are still used in clinical practice. MethodsBody surface area (BSA)- and concentration-based HIPEC protocols were clinically and pharmacologically evaluated in a randomized phase III clinical pilot trial. Oxaliplatin dose was 460mg/m (2) (BSA-based) in 2L/m (2) carrier solution (concentration-based). Platinum quantification was performed using a validated inductively coupled plasma mass spectrometry method. Three-month morbidity, mortality, and health-related quality of life (HRQOL) were assessed. ResultsThirty-one patients were randomized to either BSA- or concentration-based HIPEC. Toxicity and efficacy were higher (P<0.001) in patients receiving concentration-based HIPEC. There was no difference in pharmacologic advantage between the two groups. A higher drug concentration in the tumor nodule at the end of HIPEC was found in the HIPEC-concentration group. There was no difference in major morbidity and mortality between the treatment groups. HRQOL was decreased 3 months postoperatively in the HIPEC-concentration group. ConclusionConcentration-based chemotherapy delivers the drug in the most standardized way to the tumor nodule, resulting in increasing drug concentrations in the tumor nodule without increasing major morbidity.