Direct Measurement of Chamber Response Function and Its Application to Radiation Dose Distribution Dosimetry / 대한치료방사선과학회지

ABSTRACT

PURPOSE: To obtain the actual dose distribution from measured data by deconvolution method using the measured ion chamber response function. MATERIALS AND METHODS: The chamber response functions for 2 ionization chambers (diameter 5mm, 6.4mm) were measured, and dose profiles were measured for 10X20cm2 field size using two different detectors. The deconvolution of chamber response function from the measured data were performed for these profiles. The same procedures were repeated for 4MV, 6MV and 15MV photon energies. RESULTS: Different dose profiles were obtained for the same field with the chambers which have the different response functions. Nearly the same results could be obtained with deconvolution for the profiles from various detectors. CONCLUSION: The effect of the chamber response function can be extracted by deconvolution method. Deconvolved dose profile using various ionization chambers gave better dose distributions. Technical improvements are needed for practical application.