The Basic Research Of Laser Treatment Planning System Designed To Liver Cancer

Objective:The laser treatment planning system for liver carcinoma is designed to make the laser can be very good envelope liver carcinoma and reduce the damage to normal tissues, through the reasonable laser probe layout. In the treatment, we need to know the damage degree of the laser, so can choose the appropriated laser energy. It is hard to know the damage range and laser energy distribution in biological tissue through direct measurement method of clinical.So,it is often to use the method by numerical simulation analysis. Monte Carlo method, that is, to use statistical methods to analyze the laser photon transport in the liver tissues is the best method to study the optics of tissue. Monte Carlo method used to establish the organization in laser dose mathematical model to explore the laser irradiation for the damage of liver tissue. The laser therapy of liver cancer determine the appropriate dose for further study of laser therapy for cancer treatment planning system to organize and optical preparations.Turn the CT sectional image into three-dimensional imaging based on VTK, in order to make better treatment programs for patients with liver cancer. Allow physicians to the right in three-dimensional vision of a better analysis of diseased tissue in order to facilitate better development of liver cancer patients in treatment programs.Methods:Monte Carlo method, to establish different optical parameters of normal tissue and tumor tissue dose of mathematical model of the organization, theoretical calculations using photon-photon transmission in the process of the various situations encountered, using a large number of photons counted individually VRMC technology transfer trajectory, statistics embedded in normal tissue and tumor tissue macro-photon energy distribution. Establish VTK visualization development environment based on VC6.0, obtain the patient's CT images of DICOM format, use VTK filter and Laplacian sharpening template for pre-treatment of the image, and then use Ray-Casting algorithm for three-dimensional reconstruction. Results:Light damage of Monte Carlo simulation will decay with the depth of the organization increased, and the photons in the organization will form the second peak at the edge of different tissue. Tissue damage is a threshold process, each dose curve can be regarded as the threshold curve, degree of injury increases exponentially with distance attenuation. Monte Carlo simulated the laser photons in the spread of liver tissue,obtained the photons distribution in the liver tumor tissue, as well as the different energy and time of laser irradiation on the degree of liver injury, calculated the optimal exposure time and the irradiation energy. We can get three-dimensional images with a higher resolution and a faster imaging speed through this method, which can also cut, rotate and zoom.Conclusion:According to the different organization with the different optical parameters,laser energy distribution will form a significant increase at the junction of the tissue edge. Thus available, the damage at the dege of organization will have a significant increased by use of laser irradiation on the liver cancer, according to the damage to identify the scope of cancer tissue will observe more accurately determine the diseased tissue of the the scope and size than normal with the naked eyes. The results showed that amount of light intensity can cause shallow overall tumor tissue photo-damage, deep photo-damage to normal tissue associated with their degree of injury with the distance increases. Laser role mainly in heat-damaged, the best power 6-8 W, the best time to 8-10 min, maximum damage range of about 20mm in diameter. VTK-based light projection algorithm can be used for three-dimensional reconstruction of human liver tissue,conducived to a doctor visually observed the shape and location of diseased tissue for the diagnosis and therapy. VTK software enables intuitive segmentation of three-dimensional image processing, which can give a great help at the latter part of research for the rational distribution.