When it comes to acne scars, tretinoin is generally fine for maintenance, once appropriate treatment of the scars have been performed. Putting aside all the marketing hype and social media buzz surrounding this or that, expensive, so-called "energy-based" gizmos out there, like fraxel lasers and RF microneedling devices, simple, relatively inexpensive subcision, whiich I have personally been using since 1995, has a long track record for safety and efficacy for elevating and smoothing all kinds of indentations, whether from acne scars anywhere on the body or cellulite, etc.. You would be wise to consult with an experienced, board certified cosmetic dermatologist and best of luck.