Comment by 7goatman on 12/03/2025 at 19:54 UTC

3 upvotes, 1 direct replies (showing 1)

View submission: Ask Anything Wednesday - Biology, Chemistry, Neuroscience, Medicine, Psychology

For photodynamic therapy I know one of the limitations is tissue penetration, so why can’t they just use a more powerful light?

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Comment by cosmin_c at 13/03/2025 at 06:53 UTC

3 upvotes, 0 direct replies

Photodynamic therapy isn't light only therapy, but also includes drugs that become active when activated by light. So the tissue penetration problem may be related to those drugs as well rather than only the light.

At the same time, those drugs turn toxic when exposed to light and even though generally photodynamic therapy is gentler than let's say systemic chemotherapy, it can still cause burns and tissue damage. If you put those drugs deeper into the tissue, all you get is further tissue damage affecting healthy tissue as well as malignant tissue.