Radiation Dose Based On Film Analysis System

The trend toward conformal techniques in radiation therapy necessitates an accurate and practical method for verification of irregular three-dimensional dose distributions. The system used for verification of three-dimensional dose distributions includes hardware and software. This work takes part in the design of the hardware-phantom and completes the dedicated software-the dose analytic system based on film for radiation therapy.Phantom is made of tissue-equivalent materials, include lung>bone> spinal cord etc. It can not only be used for measuring the conformal dose distributions using radiographic films separated by tissue-equivalent materials but also can be used for measuring the point dose using ionization chambers and diodes.The dose analytic system based on film for radiation therapy is developed to obtain the optical density-to-dose sensitometric curve, scan or read the film image, convert the scanned pixel gray value to the dose value according to the sensitometric curve, set the normalized point and normalize all the points' dose, extract the isodose curve, reconstruct the dose distributions. At last, we do the experiment using the dose analytic system based on film for radiation therapy, and some dose distributions reconstructed images are given.