OHIF Viewer hangs importing large ROI (RTSTRUCT) files

[eloc...@gmail.com]

Hi all,

We have RTSTRUCT DICOM files which typically have multiple contours saved per file. These files are uploaded as ROI assessors in the XNAT. Small imported RTSTRUCT files overlay on the image very well. But we've run into problems with the OHIF viewer hanging when we try to import larger RTSTRUCT files with many (~>5) contours to overlay on the image. Is it possible that this is due to a memory or heap size issue? I can supply a sample image and RTSTRUCT for example and testing.

Much thanks,

Eve

[Simon Doran]

Hi Eve,

  This is behaviour we have observed before and I think that your diagnosis is probably correct.

  The best way to check is to find the logs/xnat-roi.log file that sits underneath the xnat user's home directory (assuming a standard 1.7.x installation). You are likely to find a message that tells you that your are out of Java heap space. If this is indeed the case, the solution is to find the Tomcat configuration file where JAVA_OPTS is specified and increase the  -Xmx setting.

  It's certainly possible to display very large and complex RT-STRUCT files, as in the real-world radiotherapy example below. However, be warned, files with lots of contours take a very long time to load. We haven't yet found a good way of reducing this time, as some of these files are just very large. I have also seen these files take a long time to load even on specialist RT systems such RayStation and they certainly give OsiriX a real headache (think spinning beachballs!).

  Best wishes,

Simon

 

[eloc...@gmail.com]

Thank you very much for your help Simon. Our Xmx is sitting at 8192m, and indeed, I needed to give it a very long time to load. 

Best,

Eve

[Simon Doran]

Yes, the load time is currently a big headache to us and we are trying to think of strategies to improve performance here.

Best wishes,

Simon

[eloc...@gmail.com]

Thanks again Simon. I wrote a Python script to strip the contours into separate files for the time being.

In a slightly (un)related question, are there any plans to be able visualize DICOM-based overlays or other radiotherapy (RT) DICOM objects, like RT-DOSE in the Viewer? 

Best,

Eve

[Simon Doran]

Hi Eve,

  In the medium term, definitely, but it won't be in the next viewer release, as we are just about to have a feature freeze and start beta-testing.

  Best wishes,

Simon

[eloc...@gmail.com]

Dear Simon,

Our group is still very interested in viewing RTDOSE or other overlays on scans. We were wondering if there are any updates on whether this feature is on the horizon for OHIF and/or XNAT in the near future? 

Thanks,

Eve