Personalized treatment planning for photodynamic therapy (PDT) requires knowledge of the spatial and temporal co-localization of photon, photosensitizer (PS), and oxygen throughout the planning treatment volume (PTV). Present iPDT pre-treatment planning tools assume population average tissue optical properties and homogenous PS distribution throughout the PTV. However, the PS accumulation show large inter and intra-subject variability. This study addresses the impact of PS heterogeneity on treatment planning, especially for iPDT, and investigates potential methods to predict heterogeneity using existing clinical imaging techniques.

The present work introduces a compact, homogenous, side-fire diffuser for delivering high-energy laser pulses to the prostate for photoacoustic imaging. The diffuser fabrication involves development of a corrugated window on one side of the fiber using laser micromachining and coating the rest of the surface with reflective metal like silver to redirect the light to the window side. Ongoing tests will evaluate the side-fire efficiency and illumination uniformity before coupling with a high-energy Q-switched laser for photoacoustic imaging.

Exploiting the optical absorption contrast of blood hemoglobin, photoacoustic microscopy (PAM) is an emerging technology for label-free imaging of the microvasculature, which plays an essential role in supplying biological tissue with oxygen and sustaining metabolic activity in vivo. The multi-parametric PAM developed in my lab enables comprehensive and quantitative characterization of microvascular structure, function, and tissue oxygen metabolism at the microscopic level. In this talk, I will present their latest progress on the development of PAM and the integration of PAM with other intravital light microscopy techniques for studying brain function and energy metabolism across spatiotemporal scales.

XACT represents a groundbreaking imaging modality that offers the capability to image the human body more rapidly and with a lower radiation dose than conventional CT imaging. It holds promise for use in biomedical imaging and radiotherapy. The swift progress of XACT imaging—from its initial conceptualization to clinical trials on patients in under a decade—will be explored, together with advanced concepts and future prospects.