Even if they have Ph. D.’s, in a clinical setting PA’s are not to be called “doctor”. All the PA’s I have met ask their patients to call them by their first name. (Many call them “doctor” anyway.)
https://forums.studentdoctor.net/threads/do-you-call-a-pa-doctor.90801/
한국말로도 적당한 말이 없는게 문제네요, 학위는 석사인데 그렇디고 석사 선생님 그렇기도 뭐하고.
그냥 선생님 또는 의사선생님 이라고 하면 될 것 같네요.