Improvement of tumor response to photodynamic therapy by manipulation of tumor oxygenation in an in-vivo model system

Qun Chen; Zheng Huang; Hua Chen; Howard Shapiro; Jill Beckers; Fred W. Hetzel

doi:10.1117/12.482964

12 September 2002 Improvement of tumor response to photodynamic therapy by manipulation of tumor oxygenation in an in-vivo model system

Qun Chen, Zheng Huang, Hua Chen, Howard Shapiro, Jill Beckers, Fred W. Hetzel

Author Affiliations +

Proceedings Volume 4916, Optics in Health Care and Biomedical Optics: Diagnostics and Treatment; (2002) https://doi.org/10.1117/12.482964
Event: Photonics Asia, 2002, Shanghai, China

Abstract

Photodynamic therapy (PDT) requires molecular oxygen during light irradiation in order to generate reactive oxygen species. Tumor hypoxia, either pre-existing or induced by PDT, can severely hamper the effectiveness of PDT treatment. Lowering the light irradiation dose rate or fractionating a light dose may improve cell kill of PDT induced hypoxic cells, but will have no effect on pre-existing hypoxic cells. In this study, hyper-oxygenation technique was used during PDT to overcome hypoxia. C3H mice with transplanted mammary carcinoma tumors were injected with 12.5 mg/kg Photofrmn and irradiated with 630 nm laser light 24 hours later. Tumor oxygenation was manipulated by subjecting the animals to 3 alp hyperbaric oxygen or normobanc oxygen during PDT light irradiation. The results show a significant improvement in tumor response when PDT was delivered during hyper-oxygenation. With hyper-oxygenation, up to 80% of treated tumors showed no re-growth after 60 days. In comparison, only 20% of tumors treated while animals breathed room air did not re-grow. To explore the effect of hyperoxygenation on tumor oxygenation, tumor PO2 was measured with microelectrodes positioned in pre-existing hypoxic regions before and during the PDT. The results show that hyperoxygenation may oxygenate pre-existing hypoxic cells and compensate for oxygen depletion induced by PDT light irradiation. In conclusion, hyper-oxygenation may provide effective ways to improve PDT treatment efficiency by oxygenating both pre-existing and treatment induced cell hypoxia.

Citation Download Citation

Qun Chen, Zheng Huang, Hua Chen, Howard Shapiro, Jill Beckers, and Fred W. Hetzel "Improvement of tumor response to photodynamic therapy by manipulation of tumor oxygenation in an in-vivo model system", Proc. SPIE 4916, Optics in Health Care and Biomedical Optics: Diagnostics and Treatment, (12 September 2002); https://doi.org/10.1117/12.482964

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available