From my research, photodynamic therapy is when a photosensitive chemical is applied topically to dysplasia in the mouth (I think it can also be given intraveneously but I'm not sure how it is targeted to the tissue). A laser, tuned to the frequency of the chemical, is then aimed at the tissue. Only the coated tissue is distroyed and healthy epithelial cells return to the site. Apparently there is a low rate of dysplasia recurring.

Most of the trials are out of the US but there is an ongoing study at Northwestern in Chicago- however you have to be cancer free for two years to participate. I would be very interested to hear that someone else is performing this treatment.

Catherine, SCC floor of mouth DX 2010,unclear margins, PET scan clear, no chemo or rad,biopsy in 9/2010, 2nd excision 10/2010 didn't get all carcinoma in situ; partial gloss & excis. right floor 2/2/2011 margins clear. Part.gloss-10/5/2011 sev dys clean marg. HPV neg. Don't smoke or drink. SCC floor of mouth left side 4/2016. Dysp excis. rt palate 7/2017 Part gloss sev dys lat marg 2/2019 Part gloss free flap rt neck disc 5/2020 Part gloss bilat neck disc 7/2020 33 rad 3 cis.