Photodynamic Therapy

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

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

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

4. Photodynamic Therapy • Three components • Photosensitizer • Light • Oxygen • Taken separately- non-harmful • Combined- cytotoxic effects

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

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

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

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

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

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

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

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

14. PDT at MD Anderson

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