Interstitial Thermometry During Photothermia Therapy

Hyperthermia treatment techniques have established the need for multi-site temperature measurement in order to ensure that the target volume of tissue receives the proper thermal dose. This dose is defined as the desired temperature for the desired period of time. This has classically been accomplished by thermocouples and, more recently, by other techniques. Each technique has its associated shortcoming. With the use of laser induced volumetric heating of tissue, the measurement of treatment temperatures is even more difficult. High light intensities in the area of treatment complicate the placement and accuracy of measurement devices. This effort addresses two complimentary techniques for the measurement of temperatures around an interstitial laser power applicator with emphases on simplicity, size, accuracy, and economy. The techniques to be investigated are miniature thermistors and an all optical method based on temperature dependent change of absorption. Proof of principal experiments will be performed to demonstrate the effectiveness of the proposed techniques. Breadboard devices will then be constructed to demonstrate the geometries consistent with a manufacturable device.