Proton beam therapy can potentially offer improved treatment for cancers of the head and neck and in paediatric patients. There has been a sharp uptake of proton beam therapy in recent years as improved delivery techniques and patient benefits are observed. However, treatments are currently planned using conventional x-ray CT images due to the absence of devices able to perform high quality proton computed tomography (pCT) under realistic clinical conditions. A new plastic-scintillator-based range telescope concept, named ASTRA, is proposed here as the energy tagging detector of a pCT system. Simulations conducted using Geant4 yield an expected energy resolution of 0.7% and have demonstrated the ability of ASTRA to track multiple protons simultaneously. If calorimetric information is used the energy resolution could be further improved to about 0.5%. Assuming clinical beam parameters the system is expected to be able to efficiently reconstruct at least, 10$^8$ protons/s. The performance of ASTRA has been tested by imaging phantoms to evaluate the image contrast and relative stopping power reconstruction.
تحميل البحث