Photofrin photodynamic therapy can significantly deplete or preserve oxygenation in human basal cell carcinomas during treatment, depending on fluence rate

• Published in: Cancer research (Chicago, Ill.) Vol. 60; no. 3; pp. 525 - 529
• Main Authors: HENDERSON, B. W, BUSCH, T. M, GRECO, W. R, OSEROFF, A. R, VAUGHAN, L. A, FRAWLEY, N. P, BABICH, D, SOSA, T. A, ZOLLO, J. D, DEE, A. S, COOPER, M. T, BELLNIER, D. A
• Format: Journal Article
• Language: English
• Published: Philadelphia, PA American Association for Cancer Research 01-02-2000
• Subjects: Antineoplastic Agents - therapeutic use; Biological and medical sciences; Carcinoma, Basal Cell - drug therapy; Carcinoma, Basal Cell - metabolism; Dihematoporphyrin Ether - therapeutic use; Hematoporphyrin Photoradiation; Humans; Medical sciences; Oxygen - metabolism; Photoradiation therapy and photosensitizing agent; Treatment with physical agents; Treatment. General aspects; Tumors; Human; Porfimer sodium; Skin disease; Oxygen; Basal cell carcinoma; Photodynamic therapy; Treatment; Porphyrin; Tumoral tissue; Malignant tumor; Photochemotherapy; Photosensitizer
• ISSN: 0008-5472; 1538-7445

At high fluence rates in animal models, photodynamic therapy (PDT) can photochemically deplete ambient tumor oxygen through the generation of singlet oxygen, causing acute hypoxia and limiting treatment effectiveness. We report that standard clinical treatment conditions (1 mg/kg Photofrin, light at 630 nm and 150 mW/cm2), which are highly effective for treating human basal cell carcinomas, significantly diminished tumor oxygen levels during initial light delivery in a majority of carcinomas. Oxygen depletion could be found during at least 40% of the total light dose, but tumors appeared well oxygenated toward the end of treatment. In contrast, initial light delivery at a lower fluence rate of 30 mW/cm2 increased tumor oxygenation in a majority of carcinomas. Laser treatment caused an intensity- and treatment time-dependent increase in tumor temperature. The data suggest that high fluence rate treatment, although effective, may be inefficient.