exactly. its nice that you have a theory, but its the development that's going to take a while. I'm sure there is a scientist or group out there working on something along this lines, but it takes a while,
first they'd have to figure out a way to identify a cancer cell or 'potentianlly' cancerous cell. then they would have to make that work with a small little nano tech robot. then probably develop some way of distroying the cells that does not harm the body too much. and then again, figure out how to put that technology into a small little nano tech robot.
it would be a long process