{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Berns+Lecture+4 - Photodynamic Therapy(PDT and Refractive...

Info iconThis preview shows pages 1–14. Sign up to view the full content.

View Full Document Right Arrow Icon
Photodynamic Therapy (PDT ) and Refractive Surgery (a double-whammy lecture)
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
MOMENTUM TRANSFER Multi-photon Single photon
Background image of page 2
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Photodynamic Therapy (PDT) Photosensitizer Administration Light Irradiation Patient is administered a photosensitizing drug which accumulates “selectively” in targeted tissue. Drug is inert unless activated by specific wavelengths of light. Selective Accumulation Target Destruction tumor
Background image of page 4
Photochemistry: Type II Reaction Ground State Singlet State Light h ν O 2 1 O 2 Molecular Oxygen Singlet Oxygen Intersystem Crossing Photosensitizer Cell Death Triplet State Has a nanosecond life-time: what is significance? (Photofrin)
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Photophysics in spot irradiance = power density = W/cm 2 [From: Berns, M.(1998) Sci. Am.  198:62-7]   Jablonski Diagram (linear single photon absorption) Type II Reaction Vibrational heat
Background image of page 6
Basic sensitizer is a porphyrin (originally extracted from hemoglobin) Tetrapyrrole ring Major component of hemoglobin – (Fe) HPD = hematoporphyrin derivative (Photofrin = commercial drug) Mixture of several porphyrins Major active ingredient is Protoporphyrin IX
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
lowest lying singlet state Absorption Spectrum of Protoporphyrin IX Treatment wavelength: why is this desirable? HPD peak @ 625 nm
Background image of page 8
So does PDT work?
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Photodynamic Therapy (PDT) Photosensitizer Administration Light Irradiation Patient is administered a photosensitizing drug which accumulates “selectively” in targeted tissue. Drug is inert unless activated by specific wavelengths of light. Selective Accumulation Target Destruction
Background image of page 10
Pre-Laser and pre HPD injection Patient with recurrent breast cancer to the chest wall
Background image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
24 hours post laser exposure
Background image of page 12
What is the
Background image of page 13

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 14
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}