Quantitative contrast peritoneography for intraperitoneal chemotherapy.

Abstract

e13064 Background: Catheter-administered intraperitoneal (IP) chemotherapy is used for peritoneal surface-spreading malignancies to maximize local drug concentrations. Computed tomography (CT) peritoneography can be used to assess for catheter failure and infusate maldistribution, which may contribute to treatment failure and systemic toxicities like cisplatin-induced nephrotoxicity. There is no standard system to assess infusate distribution, and no reported outcomes data from patients assessed with CT peritoneography. We hypothesized that volume and surface area of the compartment available to IP chemotherapy is associated with overall survival and post-treatment estimated glomerular filtration rate (eGFR) in malignant peritoneal mesothelioma (MPM) patients. Methods: Chart review identified 38 MPM patients who underwent CT peritoneograms while receiving IP cisplatin between 2000 and 2011. Volume and surface area of the contrast-filled compartments were calculated by semiautomated computer algorithm supervised by a physician. We retrospectively tested whether surface area and volume were associated with overall survival and post-treatment eGFR, controlling for demographic and disease factors. Results: Larger surface areas were associated with decreased likelihood of mortality, controlling for volume, age, sex and histologic subtype (Hazard Ratio=.999 cm-2, p=.035). Larger volumes correlated with higher post-treatment eGFR, controlling for pre-treatment eGFR, body surface area (BSA), surface area and the interaction between BSA and volume (β=.154 cc/min/cm3, p=.017). Conclusions: The association of larger surface areas with improved overall survival is consistent with more direct drug contact with potential areas of tumor spread. The association of larger volumes with higher post-treatment eGFR is consistent with less cisplatin diffusion into the circulation due to lower intra-abdominal pressures, which vary inversely with volume. CT peritoneography is an appropriate modality to assess distribution of catheter-administered intraperitoneal chemotherapy. Quantitative analysis of contrast-filled compartment surface area and volume may be predictive of treatment efficacy and side effects.