$ sudo apt-get update
$ sudo apt-get install libdcmtk8 

libdcmtk8 is installed in your system.

Make ensure the libdcmtk8 package were installed using the commands given below,

$ sudo dpkg-query -l | grep libdcmtk8 *

You will get with libdcmtk8 package name, version, architecture and description in a table

libdcmtk8 package basic information: