Determination of light fluence inside a pleural cavity

Abstract

s / Photodiagnosis and Photodynamic Therapy 12 (2015) 325–375 345 A qualitative study of in vivo protoporphyin IX fluorescence build up during occlusive treatment phase C. Louise Campbell1,2,3, Natalia Inada1,2,3, C. Tom1,2,3, A. Brown1,2,3, Kenneth Wood1,2,3, Ronan Valentine1,2,3, Ana Gabriela Salvio1,2,3, Harry Moseley1,2,3, Vanderlei Bagnato1,2,3 1 Physics and Astronomy, University of St Andrews, Scotland, United Kingdom 2 Photobiology Unit, Ninewells Hospital, Scotland, United Kingdom 3 Sao Carlos Institute of Physics, University of Sao Paulo, Brazil Photodynamic therapy comprises three main stages: firstly, a prodrug is topically applied; secondly, during the occlusive treatment phase, and thirdly, the treated region is exposed to illumination. During the occlusive treatment phase, the methyl aminolevulinate diffuses through the skin and is converted to the light sensitive molecule protoporphyrin IX (PpIX). To gain more knowledge about the build up of PpIX during this phase, we measured the PpIX fluorescence at a regular time intervals during a 3-h occlusive period. Measurements from 50 patients were recorded every 20min during the build up of PpIX, using an optical biopsy system (OBS), in an effort to monitor the build up of PpIX. Our measurements allow for comparison between different individual treatment parameters such as lesion type, location, age and skin phototype. The preliminary analysis indicates an overall linear increase of the fluorescence signal with time during the occlusion. The data suggest that there is a difference in the concentration of PpIX accumulated between patients of different skin types where phototype I presents the strongest fluorescence signal. The data also indicate that the strongest fluorescence signal is present for patients with lesions located in the face region. http://dx.doi.org/10.1016/j.pdpdt.2015.07.080 Determination of light fluence inside a pleural cavity Michele M. Kim, Rozhin Penjweini, Timothy C. Zhu Department of Radiation Oncology, University of