Cobalt-60 beam therapy in carcinoma of the esophagus.

The development by Trump and Van de Graaff (1) of x-ray equipment in the 2- to 3-MEV range, and more recently the production of readily available high-energy sources of cobalt 60 by the Atomic Energy of Canada Limited (2), have been significant forward steps in the progress of radiation physics, radiation biology, and clinical radiotherapy. The installation, in October 1951, of the first Atomic Energy of Canada Limited cobalt 60 beam-therapy unit in a treatment center of moderate size such as ours (Ontario Cancer Foundation London Clinic) placed upon us a responsibility, and presented a unique and challenging opportunity to be among the first to assess the effectiveness of this quality of nuclear radiation. We naturally looked forward to the possibility of its being more therapeutically effective by a considerable margin than conventional roentgen radiation in similar application. We have been so far sufficiently encouraged by the results of the first six years in the treatment of epidermoid carcinoma (3)...