The effect of photodynamic therapy (PDT) on glucose levels within the SMT-F mouse tumor.

Tumor glucose levels were assessed at various times following in vivo photodynamic therapy (PDT) and compared to levels following induction of anoxia in mice bearing the SMT-F tumor. Uptake of 2-deoxy-D glucose by isolated tumor cells was not altered following in vivo PDT. Tumor glucose levels following PDT were found to decline in a similar albeit slower manner to those found under anoxic conditions for 40 minutes and thereafter they declined at a greater rate. These results suggest an ischemic mechanism of tumor destruction characterized by the progressive development of stasis followed by hemorrhage resulting in the rapid depletion of extracellular glucose.