Computational Model to Simulate the Interplay Effect in dynamic IMRT delivery

17th International Conference on the Use of Computers in Radiation Therapy

物理学;计算机科学

Yoganathan, S.A.^1 ; Maria Das, K.J.^2 ; Kumar, Shaleen^2

Department of Radiation Oncology, Dr. Ram Manohar Institute of Medical Sciences, Lucknow, Uttar Pradesh, India^1

Department of Radiotherapy, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India^2

关键词: Computational model;    Evaluation program;    Motion platforms;    Patient specific model;    Respiratory motions;    Simulated results;    Target trajectory;    Treatment simulation;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/489/1/012042/pdf
DOI  :  10.1088/1742-6596/489/1/012042

学科分类：计算机科学（综合）

来源: IOP

【 摘 要 】

The purpose of this study was to develop and experimentally verify a patient specific model for simulating the interplay effect in a DMLC based IMRT delivery. A computational model was developed using MATLAB program to incorporate the interplay effect in a 2D beams eye view fluence of dynamic IMRT fields. To simulate interplay effect, the model requires two inputs: IMRT field (DMLC file with dose rate and MU) and the patient specific respiratory motion. The interplay between the DMLC leaf motion and target was simulated for three lung patients. The target trajectory data was acquired using RPM system during the treatment simulation. The model was verified experimentally for the same patients using Imatrix 2D array device placed over QUASAR motion platform in CL2100 linac. The simulated fluences and measured fluences were compared with the TPS generated static fluence (no motion) using an in-house developed gamma evaluation program (2%/2mm). The simulated results were well within agreement with the measured. Comparison of the simulated and measured fluences with the TPS static fluence resulted 55.3% & 58.5% pixels passed the gamma criteria. A patient specific model was developed and validated for simulating the interplay effect in the dynamic IMRT delivery. This model can be clinically used to quantify the dosimetric uncertainty due to the interplay effect prior to the treatment delivery.