Measuring intracellular motion using dynamic light scattering with optical coherence tomography in a mouse tumor model

We present, for the first time an in vivo implementation of dynamic light scattering (DLS) adapted to optical coherence tomography (OCT). Human bladder carcinoma tumors were grown in dorsal skin-fold window chambers fitted to male nude mice and imaged at a rate of 200 Hz using OCT. Maps of speckle decorrelation times (DT) were generated for regions of skin from individual mice as well as for regions containing tumor tissue before and after treatment with chemotherapy. Variations in DT were found between individual mice exhibiting different skin anatomy (primarily due to deterioration from the window chamber implantation). A significant difference in DT was also observed between tumor regions and surrounding normal tissue. Finally, maps of DT generated for tumor tissue treated with chemotherapy indicated a drop in DT at 24 and 48 hours after treatment. These preliminary results suggest the feasibility of using DLSOCT to measure intracellular motion as an endogenous contrast mechanism in vivo.