My mom is 97 and in great health. she has basil cell on her face and derm doc suggested 17 sessions of radiation. must she?

Quality of life...: In this case and if she is able to make decisions it is up to what she wishes especially if she wants to have a good quality of life. At her age this is a decision that needs to be taken with a grain of salt. Side effects of radiation may make her uncomfortable but it all depends on a discussion with your Dermatologist, primary care provider and if she is unable her health care proxy or caregiver.