write new Rt-structure using dicomContour library

Dear Matlab masters.

I want to put multiple 3d balls in the a specific roi: PTV.

The precedure is below:

1) read rt-structure

2) select the roi: name contains "PTV"

3) generate 3d coordinates of multiple balls > name: hot balls

4) addContour the hot balls

5) convert to dicom information using convertToinfo function

6) write dicom rt-structure using dicomwrite function

But, I face the issue.

Each 3D sphere is not sperated!

How to i solve this problem ?

The full codes is attached this post.

Best reagards

Wonjoong Cheon

Answer 1

[AKennedy]

Hello Wonjoong Cheon,

The issue you are facing, where the 3D spheres (hot balls) are not separated in the DICOM RT structure, could be due to how the contour data is being grouped and added to the RT structure.

You could try the following to resolve the issue:

• When generating the coordinates for the spheres “generateSphereCoordinatesSurface”, make sure that the points form a closed loop and are ordered either clockwise or counterclockwise.
• Each Z-value (slice) should have its own set of contours. It looks like you are already grouping the coordinates by Z-value, but make sure that each group forms a complete and separate contour for its slice.
• In DICOM RT structures, contours can be nested to represent holes or multiple regions within the same slice. Make sure that the contours you are adding are not being interpreted as nested contours within the same slice.
• Ensure that the “addContour” function is used correctly and that the contours are not being merged or overlapped inappropriately.
• Look for any constraints or requirements specific to the DICOM RT structure format. For example, some systems may have limitations on the number of contours per slice or the total number of points per contour.
• Review the process of writing the DICOM file with “dicomwrite”. Ensure that all necessary attributes are set correctly and that the contours are being written as independent structures.

Additionally, you could also browse through the following links to see if you missed some vital steps.

• For “addContour”: https://www.mathworks.com/help/images/ref/dicomcontours.addcontour.html
• For “dicomwrite”: https://www.mathworks.com/help/images/ref/dicomwrite.html?searchHighlight=dicomwrite&s_tid=srchtitle_support_results_1_dicomwrite

Hope this helps!