Fig. 5.
(a) Representative fluorescence image showing effective PDT cell killing area (indicated by the white circle) in A431 cells stained with vital dyes (live cells green, dead cells red). PDT treatments were carried out on ALA photosensitized cells (4 hour ALA incubation). A total dose of 100 J/cm2 was delivered for three beam spot sizes at the same total optical power but compensating for decreased irradiance from beam expansion with increased irradiation duration in the same proportion. (b) The mean killing diameter from image segmentation is consistent with spot size with 1, 1.5, and 2 cm beams achieving 1.09 cm (± 0.3%), 1.53 cm (± 1%), and 2.04 cm (±0.9%), respectively. Error bars show standard error.