Q: I received radiation therapy to my scalp two years ago to treat a brain tumor. I lost my hair during treatment and it has not grown back. The doctors said that this treatment might result in permanent hair loss. Is a hair transplant a viable option after radiation treatment? — K.G., Darien, C.T.

A: Unlike chemotherapy which generally causes a reversible shedding of hair (called anagen effluvium), radiation therapy can cause both reversible shedding and the permanent loss of hair follicles (scarring alopecia).  Hair can be successfully transplanted into these scarred areas – but there must be enough donor hair to do so. If the radiotherapy was localized, a hair transplant procedure is often quite effective – although several procedures may be required to achieve adequate coverage of the irradiated areas.