https://phys.org/news/2018-07-kaist-pdt-cancer-side-effects.html

However, the existing PDTs have limitations for first-line therapy because PDT agents can cause genetic variations when they have low efficiency, hence reducing treatment effects.

The key to enhancing the efficiency of PDTs is how much PS can be concentrated to a wanted site, which laser wavelength the PS is reacted to, and how fast the PS clears organelle after treatment.