X-RAD 225Cx - Small Animal Platform

The X-RAD 225Cx is a sophisticated preclinical research system. It is equipped with a three-dimensional (3D) computer controlled animal couch and an amorphous silicon flat-panel detector that can rotate 360 degrees around the subject. Submillimeter targeting utilizing fluoroscopic (2D) and cone-beam CT (3D) imaging facilitates precise delivery of high dose orthovoltage X-ray therapy. Additionally, a dedicated Monte Carlo-based small animal radiotherapy (SmART) treatment planning system provides dose calculation and visualization prior to irradiation.

High-Performance Computing

High-performance computing plays a critical role in modern radiation therapy. While advanced numerical methods for imaging and therapy are being continuously developed, it is important to utilize high-performance computing technology to overcome the computational burden associated with them for routine clinical application. One of the research focuses of the medical physics division is high-performance computation on graphics processing units (GPUs). Originally designed for graphics rendering, GPUs offer tremendously high computational power at a low cost. Their compact size and accessibility are also well-suited for the clinical environment. Over the years, we have successfully applied GPU-based computations to solve many challenging medical physics problems, ranging from low-dose cone beam CT reconstruction to Monte Carlo simulations for radiation transport. Speed-up factors of hundreds are typically achieved over conventional CPU-based computations.

The Supercomputing Online Replanning Environment (SCORE) is a research tool that has been developed on a GPU platform to facilitate clinical research in the context of online adaptive radiation therapy (ART), using advanced parallel computing technology. The SCORE system consists of 1) a user-friendly graphical user interface (GUI) for internal workflow control and external communication with commercial treatment planning systems (TPS) and clinical imaging workstations, and 2) a series of in-house developed GPU-based computational tools for fast treatment replanning, including DIR-based auto-contouring, plan re-optimization and dose calculation. SCORE also allows users to easily add their own modules to the whole system for testing.

The Treatment Assurance for Radiotherapy using GPU Enhanced Tools (TARGET) web app was created as an IMRT/VMAT quality assurance system. TARGET performs initial Monte Carlo based “second check” dose calculations based on DICOM plan information and patient CT data. TARGET also performs “delivered” dose verification by analyzing machine log files. Dose distributions are used to compute DVH and Gamma pass rates and a summary PDF report is generated. The system is built on a modular platform and has been used to automate many Monte Carlo dose calculations for research purposes.