A newly discovered method for imaging radiation beam dose profiles from Cerenkov light emission will be studied and developed for real-time tomographic imaging of the advanced therapy treatment plans. Radiation therapy (RT) for cancer is one of the most technologically advanced areas of medicine today, utilizing state of the art CT, MRI, and PET imaging together with advanced treatment planning algorithms, to design patient specific delivery of radiation from a linear accelerator (LINAC). Despite this, the tools to characterize beams accuracy are extremely slow, and to date there is still no known way to visualize the beam in quickly. The importance of this new development cannot be overstated, in terms of its potential impact in the field of RT. Current procedures to measure beam dose in water tanks or tissue phantoms involve the use of ionization chambers, which are raster scanned in a 3D water tank, so that developing a 3D image of a beam would take the majority of a 24 hour day;therefore, it is rarely done. Yet, beam verification is required, and today only partial information is used in the commissioning process of new LINACs or in the verification of complex treatment plans. This newly discovered process of imaging the beam based upon the Cerenkov emission in the medium will allow instantaneous 2D imaging and very fast tomographic profiling of each beam planned. The preliminary data proving the potential of this proposal is already established, and will be followed up with a methodical development of a realization to image LINAC beams quickly with characterization of the accuracy. Systematic testing in standard medical physics water tank set ups will be completed with validation studies as outlined by the American Association of Physicists in Medicine. The accuracy of imaging advanced Intensity Modulated Radiation Therapy (IMRT) plans for cancer treatment will be studied to illustrate how imaging the planned delivery should improve accuracy. This work will be followed up through disease specific applications in future funding, following completion of this planned basic/translational period of development.
The project will develop a completely new way to image radiation therapy treatment beams in near real time, allowing 4 dimensional dose profile and verification for individual treatment plans when delivered to water tanks. The value of this is to allow true characterization of all radiation therapy plans prior to each patient plan being delivered. The calibration will reduce errors and provide full volumetric verification for the firs time in radiation therapy.
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|Holt, Robert W; Zhang, Rongxiao; Esipova, Tatiana V et al. (2014) Cherenkov excited phosphorescence-based pO2 estimation during multi-beam radiation therapy: phantom and simulation studies. Phys Med Biol 59:5317-28|