Chemoablation consists of applying a cytotoxic chemical agent via a needle (or needle-like system) directly to a target lesion in order to destroy it. This approach has gained clinical interest because it is a minimally invasive alternative treatment for tumors and it has the potential to minimize tissue trauma, increase local efficacy, and decrease side effects and systemic toxicity, but several obstacles related to the existing delivery techniques hinder its more widespread use. Thus, a methodology must be developed to reliably inject the full dose of active agent(s) into a lesion, to monitor and control the distribution of the agent(s) within the target in real-time, and to assess the extent of damage following the chemo-injection. A hybrid cooling and deployable injection needle system incorporating thermal sensors will be designed and combined with a handheld vibratory mechanism. [Note: The following contains proprietary/privileged information that Critical Care Innovations, Inc. requests not be released to persons outside the Government, except for purposes of review and evaluation]. The device will be used to test the hypothesis that a cooling probe/injection needle assembly combined with an existing vibratory locating device will allow enhanced visualization of both the positioning of the needle within the targeted tumor as well as the delivery of a chemotherapeutic agent to the tumor without backflow. Furthermore, control of the coolant within the probe will differentially influence the adherence of tissue to the needle system as well as the distribution and retention of the chemotherapeutic agent throughout the surrounding tissue. The device will be integrated into a laptop-based ultrasound imager equipped with color-flow Doppler capability, and the necessary software will be developed to allow for computational reconstruction of the thermal fields around the device tip where drug delivery will occur. A series of experiments in phantoms and in vitro tissues will be conducted to evaluate the whole system's performance in imaging, thermal analysis, and controlling the agent(s) injection and distribution. Once fully developed, the integrated ultrasound-guided, cryo-assisted injection system (known as CryoCool"""""""") will allow for an overlay of the computed thermal fields with anatomic images, ultimately improving real-time chemoablation of tumors. Such a new device will address existing outcome variability due to operators'inexperience, inaccurate ultrasonic image guidance, and unreliability in providing safe and predictable therapeutic dose deposition.
Between 30 and 35% of solid tumors are inoperable, which represents 300,000 to 350,000 of the approximate 1 million new cancer patients a year (according to the 2004 American Cancer Society, Inc. Surveillance Research). Interventional techniques are currently explored as alternatives to surgery in the palliative or curative settings;chemoablation is such a technique and consists of applying a cytotoxic chemical agent via a needle directly to a target lesion in order to destroy it. Chemoablation is of interest because it has the potential to minimize tissue trauma, increase local efficacy, and decrease side effects and systemic toxicity, but the development of new chemoablative devices is imperative in order to exploit the full potential of this technique.
