PTW 729 Ion Chamber Array

 

Run program ConvertPTW2DImages to read in the export files from the PTW 729 ion chamber array.  This program functions identically to the ConvertEPIDImages program with the exception that it is always assumed that the off axis ratio is part of the image.  In other words, that the PTW device is not corrected for a flood view as an EPID would be.  The second assumption is that it is always 100 cm to the detectors.

 

The calibration of the PTW device does not matter if you always take a 10x10 cm field image for a known monitor unit setting.  Use the 10x10 image to calibrate your IMRT fields.

 

You will have to run a deconvolution kernel fit or use the one supplied with Dosimetry Check.   If you add material to the device, you will have to run a fit for that situation.