Development of multi-planar dose verification by use of a flat panel EPID for intensity-modulated radiation therapy

Our purpose in this study was to evaluate the accuracy of a new multi-planar dose measurement method. The multi-planar dose distributions were reconstructed at each depth by convolution of EPID fluence and dose kernels with the use of EPIDose software (SunNuclear). The EPIDose was compared with EPID, MapCHECK (SunNuclear), EDR2 (Kodak), and Monte Carlo-calculated dose profiles. The EPIDose profiles were almost in agreement with Monte Carlo-calculated dose profiles and MapCHECK for test plans. The dose profiles were in good agreement with EDR2 at the penumbra region. For dose distributions, EPIDose, EDR2, and MapCHECK agreed with that of the treatment-planning system at each depth in the gamma analysis. In comparisons of clinical IMRT plans, EPIDose had almost the same accuracy as MapCHECK and EDR2. Because EPIDose has a wide dynamic range and high resolution, it is a useful tool for the complicated IMRT verification. Furthermore, EPIDose can also evaluate the absolute dose.

[1]  Dosimetric verification of x-ray fields with steep dose gradients using an electronic portal imaging device. , 2003, Physics in medicine and biology.

[2]  P Francescon,et al.  Quality assurance of volumetric modulated arc therapy: evaluation and comparison of different dosimetric systems. , 2011, Medical physics.

[3]  Michael Gillin,et al.  Use of a two-dimensional ionization chamber array for proton therapy beam quality assurance. , 2008, Medical physics.

[4]  Y. Nakaguchi,et al.  [Comparison of dose accuracy between 2D array detectors for pre-treatment IMRT QA]. , 2012, Nihon Hoshasen Gijutsu Gakkai zasshi.

[5]  Ren-Dih Sheu,et al.  Implementation of EPID transit dosimetry based on a through-air dosimetry algorithm. , 2012, Medical physics.

[6]  Clive Baldock,et al.  Experimental investigation of the response of an amorphous silicon EPID to intensity modulated radiotherapy beams. , 2007, Medical physics.

[7]  B G Fallone,et al.  Dosimetric IMRT verification with a flat-panel EPID. , 2003, Medical physics.

[8]  C. Ma,et al.  BEAM: a Monte Carlo code to simulate radiotherapy treatment units. , 1995, Medical physics.

[9]  James F Dempsey,et al.  Verification of step-and-shoot IMRT delivery using a fast video-based electronic portal imaging device. , 2004, Medical physics.

[10]  J. Rownd,et al.  Characteristics of sensitometric curves of radiographic films. , 2003, Medical physics.

[11]  P. Lambin,et al.  Treatment verification in the presence of inhomogeneities using EPID-based three-dimensional dose reconstruction. , 2007, Medical physics.

[12]  B G Fallone,et al.  Three-dimensional IMRT verification with a flat-panel EPID. , 2005, Medical physics.

[13]  B R Paliwal,et al.  Modeling dose distributions from portal dose images using the convolution/superposition method. , 1996, Medical physics.

[14]  M. Oldham,et al.  Evaluation of a 2D diode array for IMRT quality assurance. , 2004, Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology.