PTs and OTs don't make the same amount, in general. There is a 25k dollar range in what PTs make depending on location, even for entry-level graduates.
I know several people, including myself, that have paid off loans that large - and even larger, in a year's time on a PTs salary.
All that being said, don't go to one or the other as a result of what the salary of the position may be. I find your question troubling, basing career choices on salary. You may have difficulty getting through school if you are only waiting for the paycheck.
