Would the doctor be held accountable and sinful in his work in a foreign country if hospital regulations dictate that the female patient (mostly) must completely undress before examination, and the doctor cannot change this or refuse without losing his license, while being obligated to work in this hospital for at least one year?

It is impermissible to work in a hospital that requires patients to remove their clothes, thereby necessitating the viewing of their private parts without necessity. This is because necessity is determined by its extent, and viewing private parts without necessity is forbidden. Losing a certificate is better than falling into sin, and whoever gives up something for the sake of Allah, Allah will compensate him with something better. Moreover, one can obtain a certificate from another hospital where a Muslim would not be exposed to what Allah has forbidden.