Efficient Assessment of Tumor Vascular Shutdown by Photodynamic Therapy on Orthotopic Pancreatic Cancer Using High-Speed Wide-Field Waterproof Galvanometer Scanner Photoacoustic Microscopy.

To identify the vascular alteration by photodynamic therapy (PDT), the utilization of high-resolution, high-speed, and wide-field photoacoustic microscopy (PAM) has gained enormous interest. The rapid changes in vasculature during PDT treatment and monitoring of tumor tissue activation in the orthotopic pancreatic cancer model have received limited attention in previous studies. Here, a fully two-axes waterproof galvanometer scanner-based photoacoustic microscopy (WGS-PAM) system was developed for in vivo monitoring of dynamic variations in micro blood vessels due to PDT in an orthotopic pancreatic cancer mouse model. The photosensitizer (PS), Chlorin e6 (Ce6), was utilized to activate antitumor reactions in response to the irradiation of a 660 nm light source. Microvasculatures of angiogenesis tissue were visualized on a 40 mm2 area using the WGS-PAM system at 30 min intervals for 3 h after the PDT treatment. The decline in vascular intensity was observed at 24.5% along with a 32.4% reduction of the vascular density at 3 h post-PDT by the analysis of PAM images. The anti-vascularization effect was also identified with fluorescent imaging. Moreover, Ce6-PDT increased apoptotic and necrotic markers while decreasing vascular endothelial growth factor (VEGF) expression in MIA PaCa-2 and BxPC-3 pancreatic cancer cell lines. The approach of the WGS-PAM system shows the potential to investigate PDT effects on the mechanism of angiographic dynamics with high-resolution wide-field imaging modalities.

A depth-resolved quantitative evaluation method for non-carious cervical lesions treatment with optical coherence tomography.

OBJECTIVES: The aim of this study is prognostic assessment of surface smoothness and the presence of internal bubbles after treatment of non-cancerous cervical lesions (NCCLs) using optical coherence tomography (OCT). METHODS: After treatment with NCCLs, cross-sectional images of the lesion parts of the sample were non-invasively acquired and analyzed. The surface smoothness between tooth and resin, resin and cemento-enamel junction, and the presence bubble inside resin was confirmed. In addition, using an algorithm that distinguishes between resin and dental structure based on OCT cross-sectional images, we quantitatively analyzed the amount of resin used in treating NCCLs and acquired 3D images. RESULTS: The inner structure of the resin in each sample was checked, and the presence of bubbles was confirmed. In addition, the resin sections were separated from the tomographic images acquired by OCT to visualize 3D images. The volume of resin used in the treatment part of each NCCLs samples was quantitatively analyzed as 3.7216 ∼ 14.889 mm3. CONCLUSIONS: OCT is able to measure not only the surface abrasion provided by existing intraoral scanner, but also the size and depth location of interal bubbles, which is distinctive advantage of our method. Based on our results, OCT is a significant tool for qualitative and quantitative analysis of dental NCCLs treatment before and after treatment. CLINICAL SIGNIFICANCE: The study used OCT, a non-destructive diagnostic, to reveal the structure of the resin and the location and size of bubbles after NCCLs treatment. These findings could be golden standard in determining the prognosis of NCCLs treatment.