I had 2 sessions of PT while my injury was still classified as RSI.
The second session did find more upper body involvement but w/c wouldn't approve tx for the additional sx. Dr didn't know/understand about TOS only did a basic arm pulse test on one arm.
I was just starting to read & learn about TOS at the time, so i wasn't much help with suggestions.

After I learned more and understood it better, I found a very good chiropractor that does PT type and soft tissue tx as well as adjustments when needed.
After a few months of chiro tx, I was still having some arm use limitations so I found an advanced PT guy{a university PT teacher} for a secondary evaluation and he found out that my top ribs had raised up and stuck that way {had severe scalene/scm spasms previously} - he was able to drop my top ribs back into place in one treatment.
Plus he gave me some other basic things to do at home, similar to Sharon Butlers TOS program suggestions.
It was amazing, the improvement and relief!
Both have been major helps to how I feel and maintain.

The PT sessions were in 03/04 and DC since mid 04 and the final PT guy in early 05.
I still go to chiro each month or so and the rest is stuff I do as home care.