5-FU Injections for Lip Scar. NYC Doctor Recommendations?

A little over a year ago I was in an accident that left me with a lip scar. A few months ago I had a revision that removed some of the scar and helped regain the contours of the lip, but I'm still left with some hard lumps and discomfort from the scar. I've had about 2 steroid (kenalog) injections about 1 month apart with little to no change in the scar. I'm wondering if 5-FU would be more appropriate and if there are any doctors in the NYC area with experience in this? Thanks so much!