TH‐A‐108‐01: Radiation Dose Calculations On Graphics Processing Units (GPUs): Advances and Challenges

Dose calculation is a critical component for radiation therapy. To ensure its accuracy, especially in complicated cases with large tissue heterogeneity, modern dose‐calculation algorithms contain a lot of details in their models, which demand a high computation power to achieve an acceptable level of efficiency. Especially for Monte Carlo simulation, the most accurate dose‐calculation method, its high computational burden hinders the clinical applications in many contexts. Recently, a number of research have been devoted to accelerating dose calculations for both photon and proton radiotherapy on computer graphics processing units (GPU), specialized processors with a highly parallel structure originally designed for manipulating computer graphics. The achieved speed‐up factors and accuracy, as well as the low cost in hardware setup and maintenance, indicate a great potential for the clinical applications of GPU‐based dose calculations. Yet, there are still significant challenges. For instance, there exist conflicts between the GPU's data‐parallel processing structure and the randomness of Monte Carlo simulations and hence, it is challenging to design GPU‐friendly parallelization schemes for this method. It is also desirable to develop suitable physics models that are simple for GPU implementations but attain sufficient accuracy. The proposed symposium aims to bring together experts to exchange the most recent advances in this topic, including pencil‐beam algorithms, superposition/convolution algorithms, and both photon and proton Monte Carlo simulations. Challenges in these methods and potential solutions will also be discussed. Learning Objectives: 1. Understand how GPU is used to accelerate dose calculations in radiotherapy, including pencil‐beam algorithm, superposition/ convolution, and Monte Carlo methods. 2. Understand the current status of these algorithms. 3. Understand the challenges for GPU‐based dose calculations and the potential solutions. Dr. Sami Hissoiny is employed by Elekta. The GPU code from Dr. Todd McNutt was licensed to Elekta and Gulmay.