Cancer in the elderly represents a major public health topic and its importance will increase in the future because of increased life expectancy and ageing. Cancer prognosis is worse due to late diagnosis, frequent comorbidities and treatment often considered as suboptimal. Reference treatments were primarily validated for younger or selected elderly patients and experimental data collected on most vulnerable are rare. Oncogeriatrics development for 15 years made it possible to consider two fundamental aspects, which are the geriatric evaluation, from the most simple to the complete one, and the development of specific trials. In addition, a strong institutional policy allowed promotion, on the French national territory, of regional experiments thanks to Pilot Units of Oncogeriatrics Coordination (UPCOG). The question of the interest of a geriatric evaluation in radiotherapy is related mainly to the difficulties of tolerance and observance of this treatment, but also with its effectiveness and this review explores the main curative, adjuvant and palliative indications as well as research perspectives.