Reactive Oxygen Species Explicit dosimetry for Pleural PDT.

Preclinical studies show improved prediction of treatment outcome using [ROS] rx than light fluence rate or PDT dose. We demonstrate ROSED in a clinical setting. Explicit dosimetry of light fluence, photosensitizer concentration, and oxygen concentration is used to quantify the reactive oxygen species explicit dosimetry (ROSED) during Photofrin-mediated pleural PDT. Light fluence and photosensitizer concentration were measured by a customized multi-channel PDT dose dosimeter system. Diffuse correlation spectroscopy (DCS) contact probes were sutured to the pleural cavity wall after surgical resection of pleural mesothelioma tumor to monitor tissue blood flow (BFI) during intraoperative PDT treatment. Tissue oxygen concentration can be determined by utilizing tumor blood flow measured by DCS. Large inter- and intra-patient heterogeneities in [ROS] rx were observed although an identical light dose of 60 J/cm² was prescribed to all patients. This study summarizes the current results of ROSED for a Phase II pleural PDT clinical trial. [ABSTRACT FROM AUTHOR]