You're on the right track! "In" means "master" in Dovahzul. However, Vokriiin would have too many i's in a row and might sound silly to you. Maybe Invokrii will work for you.

Other words to consider using are "aus" (suffer) - Invoaus (Master, undo, suffer), Voausin (Un, suffer, master)

"slen" means "flesh", but that might be too "icky" for the aesthetic of a doctor.

EDIT: I have to add that my suggestion is for Dovah-style name only. If you want an actual description, I'd add "Insevokrii" (Master of restoration)

I've always used "munsevokrii" "man of restoration" (note: mun is generally regarded as gender neutral so it works for non males as well).