gdcmtar: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/gdcmtar - from package: libgdcm-tools

You may install the required package with command apt-get install {package}
Error in other languages:
gdcmtar: bevel nie gevind nie
gdcmtar: comandă negăsită
gdcmtar: comando não encontrado
gdcmtar: commande introuvable
gdcmtar: command not found
gdcmtar: käsku ei ole
gdcmtar: không tìm thấy lệnh
gdcmtar: komanda nerasta
gdcmtar: Kommando nicht gefunden.
gdcmtar: kommandot finns inte
gdcmtar: komut yok
gdcmtar: nie znaleziono polecenia
gdcmtar: níor aimsíodh an t-ordú
gdcmtar: no se encontró la orden
gdcmtar: no s'ha trobat l'ordre
gdcmtar: opdracht niet gevonden
gdcmtar: parancs nem található
gdcmtar: perintah tidak ditemukan
gdcmtar: príkaz nenájdený
gdcmtar: příkaz nenalezen
gdcmtar: команда не найдена
gdcmtar: командата не е открита
gdcmtar: 命令找不到
gdcmtar: コマンドが見つかりません