Can children be around a patient going through chemotherapy with stage 4 lung cancer?

Cautiously: The main issue is that someone on chemotherapy is going to be very susceptible to infections. As a result, make sure that your kids aren't sick, don't have fevers or runny noses, etc before you bring them round. It's also a good idea to make sure you kids have had all their vaccinations.

Yes: I see why not. If it's a family member or a relative, they should be regarded as a team player. I've been told stories about people who were about to die but because of a child's presence in the house, they were able to motivate themselves enough to have their life extended for a few more years.