My Dad had cancer of his tongue. He had a radical operation where 45% tongue was amputated, tumours further down his throat (still on his tongue) were removed along with lymph nodes in his neck. 

My dad unfortunately also suffered with lymphodema and obviously compression bandaging not an option with the face. He eventually saw lymphodema nurse and was advised to use tape (kinesiology tape) to help drain the fluid. It took some time but it worked. 

I hope your brother is doing ok.