Evaluation of Fractionated Photofrin-mediated Photodynamic Therapy Using Different Light Fluences with Reactive Oxygen Species Explicit Dosimetry (ROSED)
Sun, Hongjing Rastogi, Vivek Zhu, Timothy C.
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DOI/PMID/Link: 10.1117/12.2650434
Abstract
Photodynamic therapy (PDT) is an established modality for cancer treatment, and reactive oxygen species explicit dosimetry (ROSED), based on direct measurements of in-vivo light fluence (rate), in-vivo photofrin concentration, and tissue oxygenation concentration, has been proved to provide the best dosimetric quantity which can be used to predict non-fractionated PDT outcome. This study performed ROSED for Photofrin-mediated PDT for mice bearing radiation-induced fibrosacorma (RIF) tumor. As demonstrated by our previous study, fractionated PDT with a 2-hour time interval can significantly improve the long-term cure rate (from 15% to 65% at 90 days), and it tends to increase as the light dose for the first light fraction gets larger. This study focused on further improving the long-term cure rate without introducing apparent toxicity using combinations of different first light fraction lengths and total light fluences. Photofrin was injected through the mouse tail vein at a concentration of 5 mg/kg. After 18~24 hours, treatment was delivered with a collimated laser beam of 1 cm diameter at 630 nm. Mice were treated using two fractions of light fluences with a 2-hour dark interval. Different dose metrics were quantified, including light fluence, PDT dose, and [ROS]rx. In addition, the total reacted [ROS]rx and treatment outcomes were evaluated and compared to identify the optimal light fraction length and total light fluence. Keywords: Photofrin; explicit dosimetry; light fractionation; photodynamic therapy; reactive oxygen species.
Year Published | 2023 |
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Country | United States |
Rank | Positive |
Journal | Proceedings of SPIE |
Primary Topic | Whole Body |
Secondary Topic | Cancer |
Tertiary Topic | Photodynamic Therapy |
Model | Mouse |
Wavelength (nm) | |
Complement/Comparison | Photofrin |