DT[S package Loads a package using the SSIS Service. The package argument specifies the folder and name of the package to ...

DT[S] package

Loads a package using the SSIS Service. The package argument specifies the
folder and name of the package to retrieve.

However, you can use the DTS option in conjunction with the Server option.

If you omit the Server option, the default local instance of the SSIS Service
is assumed.

If you use the DTS option in conjunction with any of the following options, 
dtexec fails: 
o File 
o SQL