Experimental verification of the planned dose perturbation algorithm in an anthropomorphic phantom

7th International Conference on 3D Radiation Dosimetry

Feygelman, V.^1 ; Opp, D.^1 ; Zhang, G.^1 ; Stevens, C.^1 ; Nelms, B.^2

Department of Radiation Oncology, Moffitt Cancer Center, Tampa, FL 33612, United States^1

Canis Lupus LLC, Merrimac, WI 53561, United States^2

关键词: Anthropomorphic phantoms;    Cylindrical phantoms;    Dose calculation;    Dose profile;    Dose reconstruction;    Experimental verification;    Independent measurement;    Volumetric perturbations;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/444/1/012047/pdf
DOI  :  10.1088/1742-6596/444/1/012047

来源: IOP

【 摘 要 】

3DVH software is capable of generating a volumetric patient VMAT dose by applying a volumetric perturbation algorithm based on comparing measurement-guided dose reconstruction and TPS calculated dose to a cylindrical phantom. The primary purpose of this paper is to validate this dose reconstruction method on an anthropomorphic heterogeneous thoracic phantom by direct comparison to independent measurements. Reconstructed "patient" doses compare well with the independent dose profile measurements in the unit-density target inside a thoracic phantom lung. The largest differences are observed in lung and are associated with the highly modulated plan with narrow (few mm) MLC openings. Such a plan is instructive as a stress test of the algorithm but is not likely to be clinically encountered in lung. This residual disagreement underscores the fact that 3DVH is not designed to correct the errors related to the TPS dose calculations in the low-density media.