dcmdspfn: 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/dcmdspfn - from package: dcmtk

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