Conformal, fractionated radiation therapy (XRT) is variably used as a treatment alternative for active acromegaly patients, usually, after failed pituitary surgery. Our objective was to evaluate the long-term efficacy and safety of XRT using strict criteria of biochemical control. Retrospective cohort study of 94 patients (73 women, mean age at radiation 53.16 ± 12.9 years) attending a specialized multidisciplinary clinic between 1998 and 2014 with a mean duration of follow-up of 12.9 ± 7.3 years. A basal growth hormone