Multi-Parametric, Nanotechnology Enabled Ultrasound Guided Photoacoustic Imaging for Treatment Guidance, Dosimetry and Tumor Recurrence Prediction

ABSTRACT

For personalizing effective treatment strategies it is paramount to understand the dynamic changes in the microenvironment as the tumor adapts or surrenders to a therapeutic insult. Towards this goal, we present the utility of non-invasive 3D ultrasound-guided photoacoustic imaging (PAI) to understand the tumor functional and molecular heterogeneity in addition to predicting local recurrence. Photoacoustic imaging, as a nomenclature suggests, involves the generation of acoustic signals by irradiating tissue with nanosecond laser pulses and it offers functional information with high sensitivity on par with optical imaging at deeper penetration depths. In the first part of the talk, I will present the utility of PAI for monitoring photodynamic therapy (PDT), a photochemistry-based treatment modality, with a 3D atlas of the changes in tumor blood oxygen saturation (endogenous contrast) and its correlation to tumor recurrence. In the second part of the talk, I will present the utility of PAI in obtaining molecular maps of cancer biomarkers such as epidermal growth factor receptor (EGFR), with molecular targeted gold nanoparticles and drug antibody conjugates (exogenous contrast). Finally, I will present long-term strategy and directions on pushing the envelope of ultrasound-guided PAI as an important preclinical and clinical tool in tumor diagnosis, selection of customized patient-specific treatment, monitoring the therapeutic progression and overall treatment outcome.

BIOGRAPHY

Srivalleesha Mallidi received her M.S. and Ph.D. degrees in Biomedical Engineering from the University of Texas at Austin. Dr. Mallidi's master’s thesis involved custom designing ultrasound-based multi-modality imaging systems while her doctoral work explored the utility of surface plasmon resonance properties of spherical gold nanoparticles for early detection of cancer and probing nano-molecular interactions. After graduation, she joined the Wellman Center for Photomedicine at Massachusetts General Hospital as an NIH Ruth L. Kirschstein postdoctoral. She has received several Young Investigator awards, Rising Star Awards from national and international conferences such as the International Photodynamic Association. She currently directs the integrated Bifunctional Imaging and Therapeutics lab (iBIT Lab) at the Department of Biomedical Engineering, Tufts University. Her research interests are in the fields of ultrasound imaging, photoacoustic imaging, image-guided therapeutics, photodynamic therapy, and combination treatments.