Hello, My Father Had Tests Done As A Follow-up To

hello, my father had tests done as a follow-up to brachytherapy and it shows:
1. lungs hyperinflated
2. elevated right hemidiaphragm with blunted costrophenic angle
3. subtle radiopacity in right upper lung field

he has said that he has been having respiratory problems.

what type of specialist should he go see?

thanks