The topical and the pill are 2 doifferent things.
The actual Accutane works systematically, changing things LONG TERM, for life, for many.
The topical stuff cannot and will not work that way.
I have used both.
Accutane is NOT a "fix it now" drug. It is meant for long term use and you MUST commit to long consistent use of the product (like 4-6 months, which can be damned uncomfortable for some) in order to get the real benefits. Its not "Clearasil". If you stick with it that long its benefits will continue after you stop taking it. For many people, they have improvements which last for the rest of their lives.
The topical stuff has some similarities, but it does NOT work that way. Use it, get a benefit, stop it, the benefit stops (its not quite THAT black-and-white, but its close).