Segmentation of tumor in CT image using contour points of RT Struct

Hey, I am Apurva. I am currently pursuing my Masters at George Washington University.
I am currently working on analysis of the effectiveness of Radiation Therapy for the treatment of patients suffering from Head and Neck Squamous Cell Carcinoma. The dataset has been obtained from TCIA ( The Cancer Imaging Archive).
I have RTSTRUCT, RTPLAN and RTDOSE and CT files for a patient. I want to know the location of the tumor in the CT image using the coplanar points present in the RTSTRUCT information.
The Segmentations module in 3D Slicer 4.8.0 helps me create a binary labelmap using the RTSTRUCT data. However, I am not sure of how to use this labelmap to get the tumor boundary on the CT image ( or how to map the points present in the RTSTRUCT to the CT image).
Also, the Isodose module in the tutorial shows that the isodose lines will be indicated on the CT image. However, in my case, even after I click on the “Apply” option in the Isodose module, there is no change observed in the original CT image.
Can you please tell me how to proceed with the problem?

Install SlicerRT extension and load a study that has contours defined in RTSTRUCT. Slicer will load and display the contours overlaid on the CT image.

To generate isodose lines/surfaces, you need to use RTDOSE volume as input.

Which TCIA collection and data set you are looking at?

Dear Sir,
I already installed the SlicerRT extension from the 3 D
Slicer but I am not very sure how to use it because although it is
displayed in the Manage Extension section,it does not get displayed when I
click on the modules list.
I am using the TCIA HNSCC database.

SlicerRT is not one module, it is many modules, one of which is integrated with DICOM loading. You need to load the DICOM-RT files the same way as you would load other DICOM files after installing SlicerRT.

Dear Sir,
Thanks for the prompt reply. I will try this module out.

A post was merged into an existing topic: How to analyse CT data?