[en] It is generally agreed that, among the different kinds of radiations usable for radio-therapy, high energy proton beams exhibit the best ballistic specificity. However, the development of proton therapy has been hindered by the size, cost and complexity of high energy accelerators. An attempt to design not only an accelerator, but a complete proton therapy facility is presented, where the size, the investment, the complexity and the cost of operation would be minimized. A non-superconducting isochronous cyclotron has been selected for this purpose. (R.P.) 5 refs.; 2 figs.; 2 tabs