Noninvasive Thermometry Monitoring System

Abstract

A noninvasive thermometry monitoring system for determining a temperature of tissue to which hyperthermia treatment is administered is disclosed. The monitoring system may incorporate magnetic nanoparticles having known moments such that once exposed to an alternating magnetic field, the magnetic nanoparticles increase in temperature. Imaging systems can disclose the magnetic nanoparticles within a patient. The temperature of the magnetic nanoparticles can be determined by comparing the magnetic nanoparticle with known temperatures for that type of magnetic nanoparticle. The image of the magnetic nanoparticles may be compared with surrounding tissue to determine the temperature of the surrounding tissue that is exposed to hyperthermia treatment.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This patent application claims the benefit of U.S. Provisional Patent Application No. 60 / 970,566, filed Sep. 7, 2007, U.S. Provisional Patent Application No. 60 / 971,286, filed Sep. 11, 2007 and claims the benefit of U.S. Provisional Patent Application No. 61 / 027,449, filed Feb. 9, 2008, all of which are incorporated by reference.FIELD OF THE INVENTION[0002]This invention is directed to a patient monitoring systems, and more particularly, to a noninvasive thermometry monitoring system configured to monitor the hyperthermia treatment systems.BACKGROUND OF THE INVENTION[0003]Procedures such as hyperthermia, treatment of cardiac arrhythmias and heat sensitive promoters in gene therapy require temperature change monitoring. Magnetic resonance imaging (MRI) thermometry overcomes problems associated with invasive temperature monitoring techniques such as thermocouples and fiber optics. In the current MRI thermometry the temperature variation is d...

AI Technical Summary

Benefits of technology

[0008]Material with a detectable physical property at different temperatures provides a suitable alternative for thermo-mapping at different locations. Coupling the temperature dependence with a physical quantity that can be detected non-invasively provides a unique technique for temperature mapping in deep-seated tissue. Magnetic nanoparticles that have magnetic moment temperature dependence can provide the desired multifunctional actions. Magnetic nanoparticles have a contrast ability signature, temperature signature, and can be utilized as agents for hyperthermia therapy. The difference in magnetic moment between magnetic nanoparticles and surrounding tissue creates a contrast in the magnetic resonance imaging. Magnetic nanoparticles with steep variation in their magnetic moment as a function of temperature elevation provide information about the tissue temperature.

[0011]The encapsulated monitoring agent may be attached to an attenuated bacteria strain. In particular, the encapsulated monitoring agent may be uploaded to an attenuated bacteria strain. The bacteria strain with the encapsulated monitoring agent may readily enter and reside in a tumor within a living being, such as a human or animal, when placed into a bloodstream of the living being. Utilizing attenuated bacteria as a carrier overcomes the issues associated with tagging and delivering conventional monitoring agents to a site of interest such as a tumor. Genetically modified strains of bacteria, such as, but not limited to, Salmonella typhimurium, have been shown to accumulate at tumor sites when injected in tumor-bearing mice and clear rapidly from blood in normal mice. The innovative delivery system makes use of genetically modified strains of bacteria, which includes genetically stable attenuated virulence (deletion of purl gene), reduction of septic shock potential (deletion of msbB gene) and antibiotic susceptibility.

[0014]An advantage of this invention is that the monitoring system enables the temperature of tissue subjected to hyperthermia treatment to be identified to increase the effectiveness of the hyperthermia treatment.

[0015]Another advantage with this invention is that the monitoring agents may be attached to bacteria strains that are readily taken up by tumors, thereby effectively delivering the monitoring agents to tumors such that the tumors may be easily be scanned to determine the temperature of the tumors.

Problems solved by technology

However, these techniques have low temperature sensitivity and are influenced by the local motion and magnetic susceptibility variation.

However, this technique provides only a single value for the temperature, not a map of temperature distribution Furthermore, this technique requires careful design for the carrier and thus can be unreliable.

There has been work conducted on all aspects of heat application to tumors, which lead to rapid development in therapeutic applicator design and to sophistication of hyperthermia equipment.

Low oxygen levels in human tumors, referred to as hypoxia, have been linked to failure in achieving local tumor control through ionizing radiation.

These techniques, however, suffer from various limitations, such as lack of linearity, low sensitivity, dependence on tissue type, sensitivity to motion, sensitivity to susceptibility artifacts, relative temperature measurement and interrelationship with many MRI parameters.

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