The ct and bone scan are called staging. The specialists use it to come up with a treatment plan. The bone scan in particular is handy as years down the track you may have another one and it will be compared to the first one to see if you have any osteo troubles brewing.
My sis in law had pains in her side and they thought maybe a hidden hernia so had a ct scan. They found cancer in a kidney. They did a quick op, took the kidney out and she never had any more cancer happen. Never did find out what the pain was in terms of the hernia though. That scan saved her life.