[en] Introduction: The invention of the cobalt-60 (Co-60) treatment unit in the 1950’s established high energy radiation therapy, but the use of Co-60 treatment began to decline in the late 1970s. At that time linear accelerator based radiation treatment became prevalent, especially in the developed world where today utilization standards recommend that 50% of cancer patients would benefit from radiation therapy at some time during their care. Recently, the World Health Organization has reported that low and middle income countries (LMICs) account for over 60% of the world’s new annual cases of cancer and over 70% of the world’s cancer deaths. However, despite being home to 85% of the world’s population, LMICs have less than 35% of the world’s radiotherapy facilities. It is evident that most cancer patients in LMICs do not have access to beneficial radiation treatment. Until recently Co-60 units still served a dominant role in many LMICs, mainly because these reliable devices are simple and robust, and require manageable maintenance programs and little facility infrastructure. But Co-60 based radiation therapy has dwindled also in LMICs and its use is not considered even in areas that could benefit from it. We postulate that this can be attributed to a lack of development of Co-60 treatment machines and, until recently, a lack of evidence that modern dose delivery techniques are feasible with Co 60. In this paper we will present results of our research advancing modern Co-60 radiation therapy along with reports of image guided conformal treatment delivery with the MRIdian Co-60 unit (ViewRay, Cleveland OH), and developments of dedicated units (e.g. for breast treatment and total body irradiation), to support recommendations for further Co-60 development.