Radiation-enhanced Immune Response to Cancer: Workshop,

here is rapidly growing interest in the potential for syneristic, clinically relevant therapeutic responses by combinng radiation therapy with immune enhancement. Because f this interest, a small group of active researchers in this eld convened in a workshop to summarize recent preclincal research on combining radiation therapy with immunoherapy and to assess implications for translational research n humans. This first meeting developed some concepts and irections that might help to guide the development of adiation-enhanced immune responses in the clinic. The ocus of the workshop was primarily on enhancement of ctive T cell–mediated antitumor immunity through vacciation approaches, although we acknowledge that there are ther mechanisms by which the immune system can effecively react to tumors, under specific circumstances, and that adiolabeled monoclonal antibodies and adoptive transfer of mmune cells are additional promising therapeutic strategies. Participants presented recent research data. Plans for fuure directions were also discussed. Among the results preented were data showing that stimulation of in vivo prolifration and differentiation of dendritic cells with cytokines n conjunction with local high-dose radiation of the primary umors was capable of controlling both the primary tumors nd distant metastases in unirradiated lungs (1). In other elated studies, moderate doses of radiation in the clinical ange, when combined with dendritic stimulation, resulted n an “abscopal” response of a distant tumor growing in a onirradiated site in the same animal (2). Another presenation described how local radiation of tumor, at moderate oses that kill a relatively small fraction of the tumor cells, an actually modulate the phenotype of tumor cells to make hem more sensitive to T cell–mediated killing (3, 4). Other ata showed that suppression of inhibitory signals by Tegulatory cells could enhance responses of irradiated tu-