TrueBeam 2.5MV WinstonLutz

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1

Hi James,

We were trying to do the Winston Lutz test with the 2.5 MV beam on Varian TrueBeam. The contrast in the image is very good because of the low energy of the beam. The WinstonLutz module doesn’t work on these images. I have just uploaded an example image to your dropbox. I believe the problem is that the WinstonLutz module is designed for less contrast.

Best regards,
Denis

2

Hi Denis,
The attenuation of the BB is too much at this energy and causes the BB search algorithm to find a ring rather than a solid circle (due to the high and low pass thresholds used), causing it to fail. Let me work on a fix.

3

Good Day,

TB 2.5 with the same issue. Having a few error codes I was hoping to get some feed back on or is this based on the image thresholds for 2.5MV images?

Error codes:

–>637 Index Error bw_bb_img = np.where(labeled_arr==np.argsort(roi_sizes)[-3],1,0)

Index Error -3 is out of bounds for axis 0 with axis 0 with size 1
few other errors at 2,116,72,565,648. Can you include me in what we can do to fix this.
Awesome program btw!
Jamey

4

I believe I have a fix for this. Will roll into v2.2.7.

5

Thanks for this.