Contrast-enhanced ultrasound applications in interventional oncology
Contrast-enhanced renal ultrasound showing a renal cell carcinoma 3 months post cryoablation. Nonlinear signal is observed from microbubbles (right image) within the active blood supply in the kidney and liver. However, a complete lack of signal is observed within the treated mass, indicating no residual vascularity and effective treatment.
The use of ultrasound contrast agents is useful for monitoring and assisting various interventional oncology procedures including ablations and embolizations of solid tumors. We are currently using both 2D and 3D ultrasound to guide, augment, and monitor responses to these therapies. The techniques include using ultrasound contrast agents for treatment planning and probe guidance, evaluating residual vascularity post treatment, and using ultrasound-triggered microbubble cavitation to sensitize tumors to therapy.
Localized drug delivery via ultrasound-sensitive drug carriers
In vivo microbubble-assisted oxygen delivery to hypoxic tumors. Left: Ultrasound images of a tumor and oxygen probe (white arrow) showing microbubble arrival within the periphery of the tumor (top image, slight peripheral enhancement denoted with green arrows), the flash-destructive ultrasound pulse used to destroy the microbubbles (middle), followed by a slight decrease in peripheral enhancement immediately after microbubble destruction (bottom). Right: Intra-tumoral oxygen levels after injection of the oxygen-filled microbubble triggered with ultrasound, the oxygen-filled microbubble alone, and a nitrogen-filled microbubble triggered with ultrasound.
Targeted drug delivery is beneficial for improving therapeutic effects while minimizing systemic toxicity. Our group is actively pursuing several ultrasound-sensitive drug delivery platforms for localized drug delivery. These include improving the delivery of chemotherapeutics to solid tumors with the use of drug-loaded, ultrasound sensitive microbubbles, delivering oxygen to solid tumors (via ultrasound sensitive microbubbles) to sensitize them to radiotherapies, and the development of ultrasound-triggered antimicrobial reservoirs which can be implanted during surgical procedures. These platforms provide localized, image guided, and temporally controlled delivery mechanisms for a variety of therapeutic applications.
High frequency ultrasound and photoacoustic imaging services
Our team provides high frequency ultrasound and photoacoustic support services to interested investigators in the Philadelphia area. In addition, we are pursuing novel applications for these modalities in preclinical and clinical research. High frequency (18-70 MHz) ultrasound enables high resolution imaging, quantification of vascularity, and quantification of blood dynamics in a variety of soft tissues. Photoacoustic imaging is a combination of ultrasound and optical imaging that provides visualization and quantification of optical contrast agents, blood oxygenation, and a variety of other molecular imaging applications. These services can provide fast, accurate, and noninvasive monitoring in species ranging from fruit flies to humans. For more information, please visit our core facility site.
3D high frequency Doppler ultrasound showing anatomical detail (in gray) combined with blood flow (in red) of a fruit fly model used for cardiac research.