Measurements for absorbed dose imaging and profiling in tissue-equivalent phantoms exposed to thermal neutrons were performed utilising a fast research reactor TAPIRO (ENEA, Casaccia, Italy). Besides the therapy dose due to the nuclear reactions of thermal neutrons with the isotope 10B, the here described method allows to measure 3D distribution of absorbed dose in tissue without boron. A good determination of such a dose is very important, because the maximum admitted fluence for therapy is established on the basis of the dose in healthy tissue. Suitable Fricke-infused tissue-equivalent phantoms have been designed, where the absorbed dose is imaged by means of optical analysis, based on measurements of visible-light absorbance. The images are detected with a CCD camera. From differential measurements with different gel compositions, the separation of dose contributions coming from different secondary radiations is obtained. Dose mapping in phantom with thermoluminescent dosimeters is performed too, and a method for separating different dose contributions has been studied, based on the analysis of the glow-curve shapes of different kinds of TLDs. The inter-comparison of the results obtained with gel-dosimeters and with TLDs has confirmed the validity of the methods. Fluence measurements with activation technique and dose calculations Monte Carlo methods have given further support.
|Titolo:||Dose Imaging and Profiling for Boron Neutron Capture Therapy Planning|
|Data di pubblicazione:||15-ott-2000|
|Appare nelle tipologie:||4.1 Contributo in Atti di convegno|