This Article  • References  • Full text PDF  • Send to a friend  • Save in My Folder  • Save to citation manager  • Permissions  Citing Articles  • Citation map  • Citing articles on Web of Science (3)  • Contact me when this article is cited  Related Content  • Similar articles in this journal  Social Bookmarking   What's this?

A Device to Optimize Photodynamic Therapy

Eric F. Bernstein, MD; Walter S. Friauf, MEE; Paul D. Smith, PhD; John W. Cole, MSEE; Roger E. Solomon; Joseph F. Fessler; Gunter F. Thomas; Christopher Black, PhD; Angelo Russo, MD, PhD

Arch Dermatol. 1991;127(12):1794-1798.

Abstract
• Photodynamic therapy involves the use of light of appropriate wavelength to excite a photosensitizer resulting in tissue destruction. The photosensitizer dihematoporphyrin ether is selectively retained in tumors allowing for tumor destruction while sparing normal structures. Accessibility of skin tumors makes them well suited for photodynamic therapy. Tissue and tumor dihematoporphyrin ether content is estimated based on the amount of dihematoporphyrin ether administered. In our study, skin dihematoporphyrin ether content was measured in guinea pigs transcutaneously by a hand-held fluorometer and compared with dihematoporphyrin ether determinations done on skin biopsy specimens. Fluorometry was performed on guinea pigs receiving 0,2.5,5, 10, and 25 mg/kg of dihematoporphyrin ether.

Transcutaneous measurements of skin fluorescence increased with increasing dihematoporphyrin ether dose and correlated well with skin dihematoporphyrin ether content as determined by extracting dihematoporphyrin ether from skin samples. Transcutaneous fluorescent measurements of guinea pigs given 0 and 2.5, 2.5 and 5, 5 and 10, and 10 and 25 mg/kg of dihematoporphyrin ether differed in a statistically significant manner.

Transcutaneous fluorometric determination of dihematoporphyrin ether content and extraction of dihematoporphyrin ether from skin samples were able to reflect differences in dihematoporphyrin ether dosing and presumably skin dihematoporphyrin ether content. However, transcutaneous fluorometry provides an instantaneous estimate of tissue dihematoporphyrin ether without the need for a tissue sample. This may provide a clinical tool to predict more accurately the optimal light dose necessary to maximize photodynamic therapy.

Author Affiliations
From the Radiation Oncology Branch (Drs Bernstein, Black, and Russo, and Mr Thomas), National Cancer Institute, and the Bioengineering Division (Dr Smith and Messrs Friauf, Cole, Solomon, and Fessler), National Institutes of Health, Bethesda, Md; and the Division of Dermatology (Dr Bernstein), Hahnemann University School of Medicine, Philadelphia, Pa.

Footnotes
Accepted for publication June 21, 1991.

Reprint requests to Division of Dermatology MS 401, Hahnemann University School of Medicine, Philadelphia, PA 19102 (Dr Bernstein).

CiteULike    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter     What's this?