BACKGROUND AND PURPOSE:Characterization of radiotherapy activity and its trend over time. Gathering of parameters for future planning of our resources, applicable to similar population areas. Performing a clinical audit of appropriate use of radiotherapy. MATERIAL AND METHODS:Analysis of 9782 patients treated between 1998 and 2008. Descriptive statistics of pathologies and social/demographic characteristics. Intention of treatment. The rate of radiotherapy utilization was estimated and compared with those considered optimal. Rate of reirradiation. RESULTS:The average global rate of radiotherapy utilization for the period was 32.7%. It increased by 23% between 1998 and 2008, while the population of the area rose by 1.04%, equaling an average 1.13 irradiations/1000 inhabitants/year. Radiation treatment has increased by 13.6, 2.3, 1.6 and 1.06 times in patients with prostate, breast, rectal and lung cancer, respectively. Eight percent of radiotherapy treatments involve concurrent chemotherapy. The proportion of treatments with palliative intent was 18.2%. The overall underutilization of radiation therapy in our environment was an estimated 13.4%. CONCLUSIONS:The grade of adequacy of radiation rates in relation with scientific evidence was globally considered suboptimal, especially in lung cancer. There was an upward trend of irradiation in breast and prostate cancer, tending toward rates considered optimal.