I’m now a bit lost I’m afraid. Could you please try starting from scratch, so deleting the directory tree where you’ve copied the DICOM example (I assume DICOM and not DICOM2?). Re-copy it from the install area of Geant4 and do exactly the following. My comments are preceded by “#”, the commands you need to run follow the “$” sign.
# Let's assume that you've deleted and recopied DICOM to ~/Bureau/DICOM
$ cd ~/Bureau/DICOM
# double check there is NO CMakeCache.txt file is this directory, you should see the "No such message..."
$ ls CMakeCache.txt
ls: CMakeCache.txt: No such file or directory
# create a directory in which to do the build
$ mkdir build
# change into it
$ cd build
# Run CMake as follows:
$ cmake -DCMAKE_PREFIX_PATH="/home/ihssane/GEANT4/geant4-v11.2.0-install;/home/ihssane/DMCTK/dmctk-3.6.8-install" -DDICOM_USE_DMCTK=ON ..
# Build
$ make
Let’s see what that does first - please post the output here, but first please see the post on How to post code snippets
Screenshots aren’t optimal for helping with these types of issue.