Evaluation of On-Board kV Cone Beam Computed Tomography-Based Dose Calculation With Deformable Image Registration Using Hounsfield Unit Modifications

We evaluated the accuracy of the dose calculation in CBCT, mCBCTMLT, and mCBCTHM with DIR for 10 patients. The results showed that dose differences in Dmean, Dmin, and Dmax in mCBCTs were within 1%, which were significantly better than those in CBCT, especially for the rectum (P<.05). Our results indicate that the mCBCTMLT and mCBCTHM can be useful for improving the dose calculation for adaptive radiation therapy.