Development of a light emitting device for the treatment of peritoneal carcinomatosis of ovarian origin by intracavitary photodynamic therapy

IntroductionPeritoneal carcinomatosis of ovarian origin (PCO) is an evolution of ovarian cancer, which is the fourth leading cause of death by cancer in women in France. PCO is defined by dissemination of cancerous cells from ovarian cancer to the peritoneal cavity. Photodynamic therapy (PDT) has been proposed in complement to the standard of care, consisting of surgery and chemotherapy. However, litterature has highlighted the lack of selectivity of available photosensitizers (PS) leading to inconclusive results [1, 2]. In this context, PRODYNOV project, initiated by our research team INSERM U1189 ONCOTHAI, has enabled the development of a patented PS. The high selectivity of this PS makes possible to carry out relevant PDT for PCO provided that an adequate illumination device would exist. In this study, we developed and assessed such a device.MethodsFirst, a test bench aiming to evaluate quantity and homogeneity of the delivered illumination has been developed. It is composed of a fantom of peritoneal cavity in which seven optical probes connected to a power-meter were placed in strategic zones characterised by high recurrence risk.Then, three illumination devices were implemented and assessed. The first one consisted of six fixed light emitting fabrics (LEF), the second one was a moving luminous wand, and the last one, a hybrid one, combined a fixed luminous wand and six fixed LEF. Light doses received by the probes have been calculated by integrating measured powers over illumination time.ResultsEach of the seven optical probes received a mean light dose of 0.68 mJ with the first illumination device (minimum: 18.37 10⁻³ mJ, maximum: 2.66 mJ), 0.11 mJ with the second one (minimum: 5.25 10⁻³ mJ, maximum: 0.35 mJ) and 0.65 mJ with the third one (minimum: 48.19 10⁻³ mJ, maximum: 1.27 mJ). With a variation coefficient of 77.1% (versus 93.1% for the first device and 119.5% for the second one), the hybrid device enabled to homogeneously illuminate the largest part of the cavity. For these reasons, the hybrid method has been selected as illumination process for PDT of PCO.ConclusionIllumination solutions for PDT of PCO have been proposed and tested. One of these solutions has been approved.The light dose necessary for an effective treatment remains to be determined and first feasability tests will be led on mini-pig by the end of the year.