I went to a new hospital for the first time yesterday and the doctor who treated me was so nice and polite.
この場合、次のような言い方ができますよ。
ーI went to a new hospital for the first time yesterday and the doctor who treated me was so nice and polite.
「昨日新しい病院に初めて行ったら、新サスしてくれた先生がとても丁寧だった」=「先生がとても丁寧に診察してくれた」
ご参考まで!