Ultrasound Backscatter Microscopy/Spectroscopy and Optical Coherence (Doppler) Tomography for Mechanism-Specific Monitoring of Photodynamic Therapy in vivo and in vitro

摘要

Photodynamic therapy (PDT) can induce a variety of tissue changes, including apoptosis, oncosis, and vascular responses. A preliminary study using two non-invasive imaging techniques, ultrasound backscatter microscopy/spectroscopy (UBM/UBS) and optical coherence/Doppler tomography (OCT/ODT), is presented. Photofrin PDT of melanoma was studied using a mouse model and imaged by both modalities in vivo. Post PDT, increase in the signal intensity and change in the backscatter spectrum were observed in UBM/UBS. A transient increase in the signal attenuation was observed by OCT and changes in the neovasculular blood flow were detected using ODT. Additional in vitro experiments were performed to examine the possible causes of the observed signal changes.