www.MathResolutions.com Software Products for the Radiological Sciences

Search

MapCheck Diode Array and Elekta EPID

Comparison of Results

Here we will compare the results of a 3D dose reconstruction using the MapCheck diode array as an input device versus using the higher resolution Elekta EPID system. This case was supplied courtesy of the University of Toledo, Toledo, Ohio.

On the left is one of seven IMRT fields integrated with the MapCheck diode array, and on the right is the same field integrated with the Elekta EPID system.



Although the MapCheck diode array has a much lower resolution, we must remember that the patient acts like a low pass filter in regard to the resulting dose distribution due to scatter within the patient.

Below is comparsion of the reconstructed dose on the left using the MapCheck diode array, and on the right using the Elekta EPID, for the transverse plane through isocenter. Green is the dose from the planning system, magenta that reconstructed here.

Notice also the gamma analysis comparision for the same planes using 3% - 3mm criteria, plotting the gamma value of 1.0. Red is where the dose > plan dose, blue where dose < plan dose.

Next we show the profile through isocenter from patient posterior to anterior. The dotted curve is from the planning system. On the left is the profile from using the MapCheck as an input device, on the right from using the Elekta EPID.

Below is comparsion of the reconstructed dose on the left using the MapCheck, and on the right using the Elekta EPID, for the coronal plane. Notice also the gamma analysis comparision for the same plane using 3% - 3mm criteria.

Below is comparsion of the reconstructed dose on the left using the MapCheck, and on the right using the Elekta EPID, for the sagittal plane. Notice also the gamma analysis comparision for the same plane using 3% - 3mm criteria.

Below is comparsion of the gamma volume histogram using the MapCheck, and on the Elekta EPID, for 3%-3mm, for the patient body volume.

This example demonstrates that 3D dose reconstructedion can be done using the MapCheck diode array to integrate the radiation fields. There was some lose in the gamma volume histogram statistic, which in this case went from 92% to 80%.

Return to DosimetryCheck page
Return to homepage