Clinical significance based IMRT QA approach

Goal: reconstruct the 3D dose distribution from the 2D intensity maps collected during IMRT QA.

Jun Lian, Tim Cullip, Kathy Deschesne and Sha Chang

The patient-specific IMRT treatment quality assurance procedure often consists of the measurement of 2-D intensity map and absolute dose. The data is compared with the computed results from TPS using a standard pass-or-fail criterion. However, the same dose discrepancy may not have the same clinical significance depending on its location. For instance, the consequence of a hot-spot in PTV is different than in spinal cord. In this project, we reconstruct the 3D dose distribution in patient planning CT from the intensity maps obtained from the 2D IMRT QA measurement. A QA statistics method is proposed to include the location of dose discrepancy points. This approach promises a new IMRT QA standard that considers the clinical significance of dose discrepancy measured in IMRT QA.

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