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Photodynamic Therapy. Presented by: Amber Burks Dental Hygiene Student Danielle Chelette Dental Hygiene Student. Lamar Institute of Technology. Introduction of Photodynamic Therapy. Photodynamic therapy, also called PDT An anti-cancer therapy Locations PDT is most commonly applied to - PowerPoint PPT Presentation
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Photodynamic Therapy
Lamar Institute of Technology
Presented by:
Amber BurksDental Hygiene Student
Danielle CheletteDental Hygiene Student
Introduction of Photodynamic Therapy
oPhotodynamic therapy, also called PDT
oAn anti-cancer therapy
oLocations PDT is most commonly applied to
oApproval 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
oThree components1.Photosensitizer2.Light3.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
oPhotosensitizer- Light absorbing compound that initiates a photochemical or photophysical reaction
oDye
o Administered intravenously or topically
o Several photosensitizers available
o Time period needed between 1st and 2nd step
o Reason for time/theories
Process of Photodynamic Therapy (cont.)
o Second step/second appointmento Light activation
o Laserso Fluorescent lights
o Several factors need to be taken into consideration when deciding which light source to use.o Size of the lesiono Costo Absorption rateo 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 abilitieso Blue light- less penetratingo 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 patientso 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-upo 35% continued to be cancer free
Clinical Uses
o Standard treatment option for:o Premalignant esophageal cancero Early - advanced lung cancer
ProcessoIntravenous administration- Porfimer (Photophrine)oLight source- laser
o2 (30 min.) treatmentso local/general anesthesia
oDestruction of tumor cellsoRe-evaluate after 1 month
KTP Laser (source of light) With Fiber Optic Catheter and Light Diffuser
PDT at MD Anderson
Future Research
oFuture is promising
oFull potential has yet to be shown
oContinuing research oNew photosensitizerso Improved existing photosensitizerso Lower photosensitivityo Longer light wavelength activation
