Treating Tumors with High Intensity Focused Ultrasound

Tumor Ablation Using MRI

An injectable liquid embolic agent mixed with piezoelectric crystals enables al method of piezoelectric material delivery and thermal tumor ablation via high intensity focused ultrasound or magnetic resonance imaging (MRI). The mixture can be delivered to a tumor in a minimally invasive manner, and the embolic agent enables specific localization and retention of the piezoelectric material in the tumor tissue while also reducing blood flow to the tumor. Subsequently, when high intensity focused ultrasound beams (HIFU) are delivered to the tumor, the piezoelectric material deposited in the tumor produces an increase in treatment zone temperature. This synergistic effect can potentially result in tumor ablation with lower HIFU energies and avoid the usual pitfalls of HIFU. In addition, the embolic agent and piezoelectric crystals serve as an echogenic target for the HIFU transducer and lend themselves to easy targeting. Such easy visualization of the target lesion can also help with treatment planning and HIFU beam modeling in conjunction with techniques such as time reversal which are frequently used when HIFU is targeted at deep tissues.

Piezoelectric Agent Localized to Tumor

Previous attempts at using piezoelectric substances for ultrasound ablation have relied on intravenous injection of these agents, which are hoped to localize in the tumor bed by active uptake. These techniques suffer from poor tumor concentration of the agents and high background uptake. This technology achieves a high local concentration of the piezoelectric agent in the tumor bed with very low background uptake by directly delivering a combination of piezoelectric material and embolic agent to the tumor (either via direct needle injection of the embolic/piezoelectric mixture into the tumor or via intra-arterial injection into the tumor bed). Tumor ablation can potentially be achieved at lower ultrasound energies due to the synergistic effect of the heating produced by the piezoelectric material as well as the decreased tumor vascularity, which reduces heat loss from blood flow and also kills tumor cells.

BENEFITS AND FEATURES:

• Novel method of tumor ablation using ultrasound or MRI
• Liquid embolic agent mixed with piezoelectric crystals
• Performs ablation with lower ultrasound energies
• Extracorporeal ultrasound transducer delivers high intensity focused ultrasound or RF pulses to treatment site
• Piezoelectric crystals produce heat from sound generation
• Embolic agent helps with high concentration local deposition of piezoelectric agent and also reduces tumor blood supply reducing local heat sinks.
• High precision; minimizes damage to surrounding tissue
• Potentially requires no MR guidance due to visibility of embolized lesion to ultrasound and potential ultrasound thermometry.
• Potentially can help plan HIFU beam geometry by enabling time-reversal modeling.

APPLICATIONS:

• Tumor embolization and ablation
• Medical devices
• Intracranial tumors
• Malignant tumors
• Benign tumors

Phase of Development - In vitro assessment