# Dose will be distorted when creating isodose surfaces

**URL:** https://discourse.slicer.org/t/dose-will-be-distorted-when-creating-isodose-surfaces/20129
**Category:** Support
**Tags:** slicerrt, radiotherapy, rtdose
**Created:** [October 13, 2021, 8:49am UTC](https://discourse.slicer.org/t/dose-will-be-distorted-when-creating-isodose-surfaces/20129 "2021-10-13T08:49:37Z")
**Posts on this page:** 4
**Page:** 1

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### Author: ![Cody\_Xie](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/cody_xie/32/10261_2.png) [@Cody\_Xie](https://discourse.slicer.org/u/Cody_Xie)
#### Post date: [October 13, 2021, 8:49am UTC](https://discourse.slicer.org/t/dose-will-be-distorted-when-creating-isodose-surfaces/20129/1 "2021-10-13T08:49:37Z")

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Dear All,

I am using SlicerRT plug-in, and I would like to **create isodose surfaces**. However, just after clicking “ **Create isodose surfaces** ”, I found that **the dose was distorted** automatically.

The two screenshots below are self-explanatory. The first screenshot is before clicking “Create isodose surfaces”, and the second one is after clicking. The three views are from the same slices. You can see that **the dose is enlarged**.

Before:

 ![Isodose_before](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/0/7/0729308964a41c8bf3e5c04969c2eb4da5c4e527.png)

After:

 ![Isodose_after](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/3/f/3fd2c9ad91c1f083e2c5e57ed6e32f6112e3b6c3.png)

Could you give me some support that how to avoid the distortion? Thank you so much!

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### Author: ![cpinter](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/cpinter/32/7995_2.png) [@cpinter](https://discourse.slicer.org/u/cpinter)
#### Post date: [October 14, 2021, 12:45pm UTC](https://discourse.slicer.org/t/dose-will-be-distorted-when-creating-isodose-surfaces/20129/2 "2021-10-14T12:45:23Z")

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It could simply be that the window/level settings have changed. Can you go to the Volumes module before and after Isodose generation and check the W/L values?

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### Author: ![Mik](https://avatars.discourse-cdn.com/v4/letter/m/958977/32.png) [@Mik](https://discourse.slicer.org/u/Mik)
#### Post date: [October 14, 2021, 1:05pm UTC](https://discourse.slicer.org/t/dose-will-be-distorted-when-creating-isodose-surfaces/20129/3 "2021-10-14T13:05:46Z")

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It looks like that the issue. Dose color table changes palette according to the isodose levels, and window level for a display dose is set to auto.

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### Author: ![Cody\_Xie](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/cody_xie/32/10261_2.png) [@Cody\_Xie](https://discourse.slicer.org/u/Cody_Xie)
#### Post date: [October 15, 2021, 7:40pm UTC](https://discourse.slicer.org/t/dose-will-be-distorted-when-creating-isodose-surfaces/20129/4 "2021-10-15T19:40:56Z")

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Thanks Csaba! That’s exactly the reason why the dose was magnified. The W/L values were 25/18 before, and 28/14 after.