attachInterrupt to touch screen event, is it possible ?

I'm using a TFT display on a MEGA 2560 with UTOUCH and UTFT. I would like to attach an interrupt to trigger when the TFT gets a touch input on the display. Is that even possible ? After reading a book called Arduino Cookbook I get the impression that an interrupt can only be attached to pin on the board. And none of those pins listed for MEGA is used by the touch screen as far as I can see.

Probably possible, but useless.

A touch event is, in microprocessor terms, extremely slow. You should be polling for such events as your main loop cycles thousands of times per second. If your loop is not doing so, there is something badly wrong with your program design. You should not be using "delay()" statements in other than a crude demonstration project.