Finding the optimal concentration of scattering media for intra-peritoneal photodynamic therapy for peritoneal carcinomatosis

Photodynamic therapy (PDT), which exerts its effects through the coexistence of light, photosensitizer, and oxygen, has emerged as a promising clinical therapeutic tool for cancer treatment. An even distribution of light energy is a prerequisite for the safe and effective treatment of peritoneal carcinomatosis. To overcome unpredictable light delivery to the irregular surface, we used light dosimetry of a peritoneal cavity filled with light scattering media. For this study, we made a 3d-printed phantom based on the CT (Computed Tomography) data of a peritoneal carcinomatosis patient. Four isotropic probes were placed inside the peritoneal cavity by creating holes to measure the scattered light in the peritoneal space. Four irradiating catheters were located in four designated spaces. In this measurement, we found the optimal concentration of scattering media for PDT is 0.15% Winuf. This phantom model and our research strategy will guide the implementation of irradiation for safe and effective PDT of peritoneal carcinomatosis.