The dual development of an optical tomographic scanner and three dimensional gel dosimeter for complex radiotherapy verification

摘要

The state-of-the-art radiotherapy delivery treatments available today require that the intended dose distributions delivered are verified by volumetric gel dosimetry. The development of tissue equivalent gel dosimeters that provide an integrated assessment of the dynamic treatments, are primarily imaged with Magnetic Resonance Imaging (MRI).This thesis describes the dual development and assessment of an optical tomographic scanner and normoxic gel dosimeter. MRI centers are currently limited in both time and resources in providing the routine imaging necessary for treatment verification. An alternative bench top imaging modality has been designed, built and developed to provide both complementary and comparable observations to MRI. It is hoped that this cost effective optical imaging system could alleviate this technological reliance. The optical tomography scanner is evaluated from a series of investigations into the capabilities and limitations of optical tomographic imaging used in conjunction with gel dosimetry.Previously, the manufacture of gel dosimeters required anoxic environments in which the presence of oxygen in the dosimeter is limited. This requirement limited the production of gel dosimeters to chemistry laboratories that possessed the required technical expertise. MRI and optical imaging have been used to investigate the properties, dose response and the batch-to-batch reproducibility of a normoxic MAGIC gel dosimeter.The results obtained are encouraging having shown successfully reconstructed optical images obtained from various dose distributions delivered to the MAGIC gel dosimeter.