Photodynamic Therapy Lamar Institute of Technology Presented by: Amber Burks Dental Hygiene Student Danielle Chelette Dental Hygiene Student

Introduction of Photodynamic Therapy o Photodynamic therapy, also called PDT o An anti-cancer therapy o Locations PDT is most commonly applied to o Approval by the U.S. Food and Drug Administration

Importance of PDT o Alternative treatment option o Our goal/purpose o Routine cancer screening o We hope PDT become more commonly accepted in the clinical practice o “prolong survival in patients with inoperable cancers and significantly improve quality of life”

Photodynamic Therapy o Three components 1.Photosensitizer 2.Light 3.Oxygen o Taken separately- non-harmful o Combined- cytotoxic effects

Process of Photodynamic Therapy o PDT is a 2 step process o First step/first appointment o Administration of the photosensitizer o Photosensitizer- Light absorbing compound that initiates a photochemical or photophysical reaction o Dye o Administered intravenously or topically o Several photosensitizers available o Time period needed between 1 st and 2 nd step o Reason for time/theories

Process of Photodynamic Therapy (cont.) o Second step/second appointment o Light activation o Lasers o Fluorescent lights o Several factors need to be taken into consideration when deciding which light source to use. o Size of the lesion o Cost o Absorption rate o Type of cancer

Process of Photodynamic Therapy (cont.) o Light gives off wavelengths that are absorbed by the photosensitizer o 3 light sources with different penetrating abilities o Blue light- less penetrating o Red light- deeper penetrating ability o When the 3 components are combined it creates a non- thermal (cold) reaction o Destruction of tumors cells

Disadvantages o Specialized equipment and training o Only used for localized tumors o Dye could unevenly disperse o Pain and swelling in affected areas after treatment o Side effects ranging from slight-severe o May experience lingering photosensitizers in the tissue lasting many days or weeks (discoloration)

Advantages o Minimally invasive treatment o Performed in an outpatient clinic o Can be used before, during, or after chemotherapy and radiation therapy o Can be used where radiation is contraindicated o Small effect on connective tissues resulting in minimal scarring o Activates immune system and low systemic toxicity o High patient tolerance rate o Lower morbidity and deformity than traditional treatments o Simple, efficient, and economical

Successful Trial o Foscan o 128 patients o Advanced incurable head and neck carcinomas o 43% out of 128 showed elimination of their tumor o 35% had half or greater tumor reduction o The patients with complete tumor elimination had a 1 year follow- up o 35% continued to be cancer free

Clinical Uses o Standard treatment option for: o Premalignant esophageal cancer o Early - advanced lung cancer  Process o Intravenous administration- Porfimer (Photophrine) o Light source- laser o 2 (30 min.) treatments o local/general anesthesia o Destruction of tumor cells o Re-evaluate after 1 month

KTP Laser (source of light) With Fiber Optic Catheter and Light Diffuser

PDT at MD Anderson

Future Research o Future is promising o Full potential has yet to be shown o Continuing research o New photosensitizers o Improved existing photosensitizers o Lower photosensitivity o Longer light wavelength activation