Treatment of solid cancers by photodynamic therapy (PDT) triggers a strong acute inflammatory reaction localized to the illuminated malignant tissue. This event is regulated by a massive release of various potent mediators which have a profound effect not only on local host cell populations, but also attract different types of immune cells to the treated tumor. Phagocytosis of PDT-damaged cancerous cells by antigen presenting cells, such as activated tumor associated macrophages, enables the recognition of even poorly immunogenic tumors by specific immune effector cells and the generation of immune memory populations. Because of its inflammatory/immune character, PDT is exceptionally responsive to adjuvant treatments with various types of immunotherapy. Combining PDT with immuneactivators, such as cytokines or other specific or non-specific immune agents, rendered marked improvements in tumor cures with various cancer models. Another clinically attractive strategy is adoptive immunotherapy, and the prospects of its use in conjunction with PDT are outlined.

Date Published: 13 May 1998
PDF: 8 pages
Proc. SPIE 3254, Laser-Tissue Interaction IX, (13 May 1998); doi: 10.1117/12.308148

Published in SPIE Proceedings Vol. 3254:
Laser-Tissue Interaction IX
Steven L. Jacques; Jeff Lotz, Editor(s)