The Development of a Precise Electron Beam Treatment System for Small Animals (II)

Animal study has been widely adopted on researches about radiation-induced biological response in radiotherapy. There is a huge and unexplored study field for animal RT systems. Current irradiating methods for small animals have no ability to provide optimal conformal dose distribution. It is necessary to have a treatment system which is capable of delivering accurate and conformal dose for small animals. This project proposes to develop a precise electron beam treatment system for small animals by the aids of animal CT and SPECT imaging, including a dose delivery system, dose calculating system, and a dose verification system. These systems can be used to focus treated spot locally for small animals. In this proposal, we propose to use electron beam for our micro-RT system instead of the photon beam used by previous studies. Electron beam has many advantages in shallow dose distribution and is easier to be collimated in small field. A dose calculating system for small animal is also critical besides a micro-RT system. This system has to precisely determine the in-vivo dose profile inside small animals with sub-millimeter resolution (i.e. 0.1 mm) by the aids of animal imaging modalities and Monte Carlo simulation. This will be the first electron beam treatment system in the world to precisely treat small animal. Such a system can boost animal studies on tumor research, including volume effect, dose response scheme, combined drug administration protocol, and normal tissue tolerance. This is the second year of a two year project. In the first year, we will install the parallel workstation and its network, design and make conical collimators or blocks, and test the lower spatial limit of pin-point ion-chambers, diamond detectors, XV-II and radiochromic films, and dosimetry gel. Besides, the LINAC will be modeled into Monte Carlo simulation. This year, we will commission the dose delivery system, construct the treatment calculating system, and collect data on gel dosimeter or phantoms simulating small animals. Also, the delivered dose will be verified in sub-millimeter level.

Project ID:PC9709-0931
External Project ID:NSC97-2314-B182-023