IMRT Inverse Planning Algorithm Minimizing the Negative Beam from Iterating the Dose Matrix
Chunsong Luo
Problem
Today, even though Intensity Modulated Radiotherapy (IMRT) have become one of the most innovative technologies in radiation oncology, IMRT planning is very complex and challenging. Despite the use of IMRT, the most appropriate form of optimization function and the most suitable calculation algorithm for inverse planning remains a challenge to medical physicists. Currently available algorithms are either stochastic and too slow to converge on a global minimum solution and have less control to the outcome target and organ-at-risk doses, or they are deterministic and fast but do not always find a global minimum solution. What needed is an IMRT inverse planning algorithm that addresses the problem of delivering an effective dose of radiation to the targeted tissue while protecting surrounding tissues and organs.
Solution
The IMRT inverse planning algorithm of the present invention calculates beam settings or multi-leaf collimator settings. Since it is a true inverse process, the mathematical beam profile generated in each calculation can produce the desired dose distribution with the desired dose voxels. The process will simultaneously iterate dose voxels within the given dose windows. From the inversely calculated beam weights, the optimization process gradually minimizes the objective function and eventually converges to the global minimum. It generates a plan that deviates minimally from the given dose constraints. All the points within the desired dose volume of the plan generated by this algorithm have doses equal to or above the corresponding minima bounded by the dose constraints. The guaranteed target dose minimum limit is a very important feature of this algorithm compared to other algorithms. The algorithm has been tested with hypothetical targets. The calculated doses are well conformed to the complex diseased targets, while protecting critical organs. The calculated results, when verified, have shown excellent matches in the dose distribution. This algorithm is feasible and can be easily implemented to solve complex target problems.
Competitive Advantage
Currently available algorithms are either stochastic and too slow to converge on a global minimum solution and have less control to the outcome target and organ-at-risk doses, or they are deterministic and fast but do not always find a global minimum solution.
Applications
Radiation oncology
Patent Status
U.S. patent No. US
6,882,702
entitled "INTENSITY MODULATED RADIOTHERAPY INVERSE PLANNING ALGORITHM" was granted April 19, 2005.
Licensing Opportunity
We are looking for a commercialization partner with capabilities in product development, sales, and marketing. An exclusive license is available.
About the Inventors
Dr. Chunsong Luo is a physicist in the Department of Radiation Oncology. Dr. Luo is an expert in planning algorithms and works closely with clinicians to develop real world solutions to clinically relevant problems to help patients with cancer.
Selected References
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on the IMRT Application. 2nd Beijing International Congress on Med. Rad. Phys. Beijing, May 2000
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X. Wu, D. Deligero, C. Luo, H. Shao, M. Watzich (2002). IMRT QA Using Superimposed Film/MOSFET Technique. Medical Physics Vol.29, No.6:1273
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C. Luo, X. Wu, H. Shao, S. Crooks, E. Bossart, A.M. Markoe (2003). The IMRT prescription vs. the IMRT achievable plan. Proceedings of Sydney 2003 World Congress on Medical Physics and Biomedical Engineering, August 2003
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