A novel method for 4D measurement-guided planned dose perturbation to estimate patient dose/DVH changes due to interplay

7th International Conference on 3D Radiation Dosimetry

Nelms, B.^1 ; Feygelman, V.^2

Canis Lupus LLC, Merrimac, WI 53561, United States^1

Department of Radiation Oncology, Moffitt Cancer Center, Tampa, FL 33612, United States^2

关键词: 4-D measurements;    Control point;    Cylindrical phantoms;    Dose distributions;    Dose reconstruction;    Organ motion;    Phantom measurements;    Theoretical framework;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/444/1/012097/pdf
DOI  :  10.1088/1742-6596/444/1/012097

来源: IOP

【 摘 要 】

As IMRT/VMAT technology continues to evolve, so do the dosimetric QA methods. We present the theoretical framework for the novel planned dose perturbation algorithm. It allows not only to reconstruct the 3D volumetric doe on a patient from a measurement in a cylindrical phantom, but also to incorporate the effects of the interplay between the intrafractional organ motion and dynamic delivery. Unlike in our previous work, this 4D dose reconstruction does not require the knowledge of the TPS dose for each control point of the plan, making the method much more practical. Motion is viewed as just another source of error, accounted for by perturbing (morphing) the planned dose distribution based on the limited empirical dose from the phantom measurement. The strategy for empirical verification of the algorithm is presented as the necessary next step.