Yes, INCISION is a Scrabble word!

Letter values in Scrabble US: I 1, N 1, C 3, I 1, S 1, I 1, O 1, N 1.

Is it a valid word?

INCISION is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

a depression scratched or carved into a surface
the cutting of or into body tissues or organs (especially by a surgeon as part of an operation)

Also: surgical incision.